rfc9240.original		rfc9240.txt
	ALTO WG W. Roome		Internet Engineering Task Force (IETF) W. Roome
	Internet-Draft S. Randriamasy		Request for Comments: 9240 S. Randriamasy
	Intended status: Standards Track Nokia Bell Labs		Category: Standards Track Nokia Bell Labs
	Expires: 1 September 2022 Y. Yang		ISSN: 2070-1721 Y. Yang
	Yale University		Yale University
	J. Zhang		J. Zhang
	Tongji University		Tongji University
	K. Gao		K. Gao
	Sichuan University		Sichuan University
	28 February 2022		July 2022
	An ALTO Extension: Entity Property Maps		An Extension for Application-Layer Traffic Optimization (ALTO): Entity
	draft-ietf-alto-unified-props-new-24		Property Maps
	Abstract		Abstract
	This document specifies an extension to the base Application-Layer		This document specifies an extension to the base Application-Layer
	Traffic Optimization (ALTO) protocol that generalizes the concept of		Traffic Optimization (ALTO) Protocol that generalizes the concept of
	"endpoint properties", which were so far tied to IP addresses, to		"endpoint properties", which have been tied to IP addresses so far,
	entities defined by a wide set of objects. Further, these properties		to entities defined by a wide set of objects. Further, these
	are presented as maps, similar to the network and cost maps in the		properties are presented as maps, similar to the network and cost
	base ALTO protocol. While supporting the endpoints and related		maps in the base ALTO Protocol. While supporting the endpoints and
	endpoint property service defined in RFC7285, the ALTO protocol is		related Endpoint Property Service defined in RFC 7285, the ALTO
	extended in two major directions. First, from endpoints restricted		Protocol is extended in two major directions. First, from endpoints
	to IP addresses to entities covering a wider and extensible set of		restricted to IP addresses to entities covering a wider and
	objects; second, from properties on specific endpoints to entire		extensible set of objects; second, from properties for specific
	entity property maps. These extensions introduce additional features		endpoints to entire entity property maps. These extensions introduce
	allowing entities and property values to be specific to a given		additional features that allow entities and property values to be
	information resource. This is made possible by a generic and		specific to a given information resource. This is made possible by a
	flexible design of entity and property types.		generic and flexible design of entity and property types.
	Status of This Memo		Status of This Memo
	This Internet-Draft is submitted in full conformance with the		This is an Internet Standards Track document.
	provisions of BCP 78 and BCP 79.
	Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-
	Drafts is at https://datatracker.ietf.org/drafts/current/.
	Internet-Drafts are draft documents valid for a maximum of six months		This document is a product of the Internet Engineering Task Force
	and may be updated, replaced, or obsoleted by other documents at any		(IETF). It represents the consensus of the IETF community. It has
	time. It is inappropriate to use Internet-Drafts as reference		received public review and has been approved for publication by the
	material or to cite them other than as "work in progress."		Internet Engineering Steering Group (IESG). Further information on
			Internet Standards is available in Section 2 of RFC 7841.
	This Internet-Draft will expire on 1 September 2022.		Information about the current status of this document, any errata,
			and how to provide feedback on it may be obtained at
			https://www.rfc-editor.org/info/rfc9240.
	Copyright Notice		Copyright Notice
	Copyright (c) 2022 IETF Trust and the persons identified as the		Copyright (c) 2022 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
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	Table of Contents		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4		1. Introduction
	1.1. Terminology and notation . . . . . . . . . . . . . . . . 6		1.1. Terminology and Notation
	2. Requirements Language . . . . . . . . . . . . . . . . . . . . 6		2. Requirements Language
	3. Basic Features of the Entity Property Map Extension . . . . . 7		3. Basic Features of the Entity Property Map Extension
	3.1. Entity . . . . . . . . . . . . . . . . . . . . . . . . . 7		3.1. Entity
	3.2. Entity Domain . . . . . . . . . . . . . . . . . . . . . . 8		3.2. Entity Domain
	3.2.1. Entity Domain Type . . . . . . . . . . . . . . . . . 8		3.2.1. Entity Domain Type
	3.2.2. Entity Domain Name . . . . . . . . . . . . . . . . . 8		3.2.2. Entity Domain Name
	3.3. Entity Property Type . . . . . . . . . . . . . . . . . . 9		3.3. Entity Property Type
	3.4. New Information Resource and Media Type: ALTO Property		3.4. New Information Resource and Media Type: ALTO Property Map
	Map . . . . . . . . . . . . . . . . . . . . . . . . . . . 10		4. Advanced Features of the Entity Property Map Extension
	4. Advanced Features of the Entity Property Map Extension . . . 10		4.1. Entity Identifier and Entity Domain Name
	4.1. Entity Identifier and Entity Domain Name . . . . . . . . 10		4.2. Resource-Specific Entity Domain Name
	4.2. Resource-Specific Entity Domain Name . . . . . . . . . . 11		4.3. Resource-Specific Entity Property Value
	4.3. Resource-Specific Entity Property Value . . . . . . . . . 12		4.4. Entity Hierarchy and Property Inheritance
	4.4. Entity Hierarchy and Property Inheritance . . . . . . . . 13		4.4.1. Entity Hierarchy
	4.4.1. Entity Hierarchy . . . . . . . . . . . . . . . . . . 13		4.4.2. Property Inheritance
	4.4.2. Property Inheritance . . . . . . . . . . . . . . . . 14		4.4.3. Property Value Unicity
	4.4.3. Property Value Unicity . . . . . . . . . . . . . . . 14		4.5. Supported Properties for Entity Domains in Property Map
	4.5. Supported Properties on Entity Domains in Property Map		Capabilities
	Capabilities . . . . . . . . . . . . . . . . . . . . . . 15
	4.6. Defining Information Resource for Resource-Specific Entity		4.6. Defining Information Resource for Resource-Specific Entity
	Domains . . . . . . . . . . . . . . . . . . . . . . . . . 15		Domains
	4.6.1. Defining Information Resource and its Media Type . . 16		4.6.1. Defining Information Resource and Its Media Type
	4.6.2. Examples of Defining Information Resources and Their		4.6.2. Examples of Defining Information Resources and Their
	Media Type . . . . . . . . . . . . . . . . . . . . . 17		Media Types
	4.7. Defining Information Resource for Resource-Specific		4.7. Defining Information Resources for Resource-Specific
	Property Values . . . . . . . . . . . . . . . . . . . . . 18		Property Values
	5. Protocol Specification: Basic Data Types . . . . . . . . . . 19		5. Protocol Specification: Basic Data Types
	5.1. Entity Domain . . . . . . . . . . . . . . . . . . . . . . 19		5.1. Entity Domain
	5.1.1. Entity Domain Type . . . . . . . . . . . . . . . . . 19		5.1.1. Entity Domain Type
	5.1.2. Entity Domain Name . . . . . . . . . . . . . . . . . 20		5.1.2. Entity Domain Name
	5.1.3. Entity Identifier . . . . . . . . . . . . . . . . . . 22		5.1.3. Entity Identifier
	5.1.4. Hierarchy and Inheritance . . . . . . . . . . . . . . 23		5.1.4. Hierarchy and Inheritance
	5.2. Entity Property . . . . . . . . . . . . . . . . . . . . . 23		5.2. Entity Property
	5.2.1. Entity Property Type . . . . . . . . . . . . . . . . 23		5.2.1. Entity Property Type
	5.2.2. Entity Property Name . . . . . . . . . . . . . . . . 24		5.2.2. Entity Property Name
	5.2.3. Format for Entity Property Value . . . . . . . . . . 25		5.2.3. Format for Entity Property Value
	6. Entity Domain Types Defined in this Document . . . . . . . . 25		6. Entity Domain Types Defined in This Document
	6.1. Internet Address Domain Types . . . . . . . . . . . . . . 25		6.1. Internet Address Domain Types
	6.1.1. Entity Domain Type: IPv4 . . . . . . . . . . . . . . 25		6.1.1. Entity Domain Type: IPv4
	6.1.2. Entity Domain Type: IPv6 . . . . . . . . . . . . . . 26		6.1.2. Entity Domain Type: IPv6
	6.1.3. Hierarchy and Inheritance of Internet Address		6.1.3. Hierarchy and Inheritance of Internet Address Domains
	Domains . . . . . . . . . . . . . . . . . . . . . . . 26		6.1.4. Defining Information Resource Media Type for Domain
	6.1.4. Defining Information Resource Media Type for domain		Types IPv4 and IPv6
	types IPv4 and IPv6 . . . . . . . . . . . . . . . . . 28		6.2. Entity Domain Type: PID
	6.2. Entity Domain Type: PID . . . . . . . . . . . . . . . . . 28		6.2.1. Entity Domain Type Identifier
	6.2.1. Entity Domain Type Identifier . . . . . . . . . . . . 28		6.2.2. Domain-Specific Entity Identifiers
	6.2.2. Domain-Specific Entity Identifiers . . . . . . . . . 28		6.2.3. Hierarchy and Inheritance
	6.2.3. Hierarchy and Inheritance . . . . . . . . . . . . . . 28
	6.2.4. Defining Information Resource Media Type for Domain		6.2.4. Defining Information Resource Media Type for Domain
	Type PID . . . . . . . . . . . . . . . . . . . . . . 28		Type PID
	6.2.5. Relationship To Internet Addresses Domains . . . . . 29		6.2.5. Relationship To Internet Addresses Domains
	6.3. Internet Address Properties vs. PID Properties . . . . . 29		6.3. Internet Address Properties vs. PID Properties
	7. Property Map . . . . . . . . . . . . . . . . . . . . . . . . 29		7. Property Map
	7.1. Media Type . . . . . . . . . . . . . . . . . . . . . . . 30		7.1. Media Type
	7.2. HTTP Method . . . . . . . . . . . . . . . . . . . . . . . 30		7.2. HTTP Method
	7.3. Accept Input Parameters . . . . . . . . . . . . . . . . . 30		7.3. Accept Input Parameters
	7.4. Capabilities . . . . . . . . . . . . . . . . . . . . . . 30		7.4. Capabilities
	7.5. Uses . . . . . . . . . . . . . . . . . . . . . . . . . . 30		7.5. Uses
	7.6. Response . . . . . . . . . . . . . . . . . . . . . . . . 30		7.6. Response
	8. Filtered Property Map . . . . . . . . . . . . . . . . . . . . 32		8. Filtered Property Map
	8.1. Media Type . . . . . . . . . . . . . . . . . . . . . . . 32		8.1. Media Type
	8.2. HTTP Method . . . . . . . . . . . . . . . . . . . . . . . 32		8.2. HTTP Method
	8.3. Accept Input Parameters . . . . . . . . . . . . . . . . . 32		8.3. Accept Input Parameters
	8.4. Capabilities . . . . . . . . . . . . . . . . . . . . . . 34		8.4. Capabilities
	8.5. Uses . . . . . . . . . . . . . . . . . . . . . . . . . . 34		8.5. Uses
	8.6. Filtered Property Map Response . . . . . . . . . . . . . 34		8.6. Filtered Property Map Response
	8.7. Entity Property Type Defined in This Document . . . . . . 36		8.7. Entity Property Type Defined in This Document
	8.7.1. Entity Property Type: pid . . . . . . . . . . . . . . 36		8.7.1. Entity Property Type: pid
	9. Impact on Legacy ALTO Servers and ALTO Clients . . . . . . . 37		9. Impact on Legacy ALTO Servers and ALTO Clients
	9.1. Impact on Endpoint Property Service . . . . . . . . . . . 37		9.1. Impact on Endpoint Property Service
	9.2. Impact on Resource-Specific Properties . . . . . . . . . 37		9.2. Impact on Resource-Specific Properties
	9.3. Impact on Other Properties . . . . . . . . . . . . . . . 37		9.3. Impact on Other Properties
	10. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 38		10. Examples
	10.1. Network Map . . . . . . . . . . . . . . . . . . . . . . 38		10.1. Network Map
	10.2. Property Definitions . . . . . . . . . . . . . . . . . . 38		10.2. Property Definitions
	10.3. Information Resource Directory (IRD) . . . . . . . . . . 39		10.3. Information Resource Directory (IRD)
	10.4. Full Property Map Example . . . . . . . . . . . . . . . 42		10.4. Full Property Map Example
	10.5. Filtered Property Map Example #1 . . . . . . . . . . . . 43		10.5. Filtered Property Map Example #1
	10.6. Filtered Property Map Example #2 . . . . . . . . . . . . 44		10.6. Filtered Property Map Example #2
	10.7. Filtered Property Map Example #3 . . . . . . . . . . . . 45		10.7. Filtered Property Map Example #3
	10.8. Filtered Property Map Example #4 . . . . . . . . . . . . 47		10.8. Filtered Property Map Example #4
	10.9. Filtered Property Map for ANEs Example #5 . . . . . . . 47		10.9. Filtered Property Map for ANEs Example #5
	11. Security Considerations . . . . . . . . . . . . . . . . . . . 48		11. Security Considerations
	12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 50		12. IANA Considerations
	12.1. application/alto-propmap+json Media Type . . . . . . . . 51		12.1. application/alto-propmap+json Media Type
	12.2. alto-propmapparams+json Media Type . . . . . . . . . . . 52		12.2. alto-propmapparams+json Media Type
	12.3. ALTO Entity Domain Type Registry . . . . . . . . . . . . 53		12.3. ALTO Entity Domain Types Registry
	12.3.1. Consistency Procedure between ALTO Address Type		12.3.1. Consistency Procedure between ALTO Address Types
	Registry and ALTO Entity Domain Type Registry . . . . 54		Registry and ALTO Entity Domain Types Registry
	12.3.2. ALTO Entity Domain Type Registration Process . . . . 56		12.3.2. ALTO Entity Domain Type Registration Process
	12.4. ALTO Entity Property Type Registry . . . . . . . . . . . 57		12.4. ALTO Entity Property Types Registry
	13. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 58		13. References
	14. References . . . . . . . . . . . . . . . . . . . . . . . . . 59		13.1. Normative References
	14.1. Normative References . . . . . . . . . . . . . . . . . . 59		13.2. Informative References
	14.2. Informative References . . . . . . . . . . . . . . . . . 60		Appendix A. Features Introduced with the Entity Property Maps
	Appendix A. Features introduced with the Entity Property Maps		Extension
	extension . . . . . . . . . . . . . . . . . . . . . . . . 61		Acknowledgments
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 62		Authors' Addresses
	1. Introduction		1. Introduction
	The ALTO protocol [RFC7285] introduces the concept of "properties"		The ALTO Protocol [RFC7285] introduces the concept of "properties"
	attached to "endpoint addresses". It also defines the Endpoint		attached to "endpoint addresses". It also defines the Endpoint
	Property Service (EPS) to allow ALTO clients to retrieve those		Property Service (EPS) to allow ALTO clients to retrieve those
	properties. While useful, the EPS, as defined in [RFC7285], has at		properties. While useful, the EPS as defined in [RFC7285] has at
	least three limitations that are further elaborated hereafter.		least three limitations, which are elaborated here.
	First, the EPS allows properties to be associated with only endpoints		First, the EPS allows properties to be associated only with endpoints
	that are identified by individual communication addresses like IPv4		that are identified by individual communication addresses like IPv4
	and IPv6 addresses. It is reasonable to think that collections of		and IPv6 addresses. It is reasonable to think that collections of
	endpoints or Provider-Defined Identifiers (PIDs), may also have		endpoints identified by Provider-Defined Identifiers (PIDs) may also
	properties. Furthermore, recent ALTO use cases show that properties		have properties. Furthermore, recent ALTO use cases show that
	of entities such as abstracted network elements as defined in		properties of entities such as Abstract Network Elements as defined
	[I-D.ietf-alto-path-vector] are also useful. However, the current		in [PATH-VECTOR] are also useful. However, the current EPS is
	EPS is restricted to individual endpoints and cannot be applied to		restricted to individual endpoints and cannot be applied to those
	those entities.		entities.
	Second, the EPS only allows endpoints identified by global		Second, the EPS only allows endpoints identified by global
	communication addresses. However, an endpoint address may be a local		communication addresses. However, an endpoint address may be a local
	IP address or an anycast IP address that may not be globally unique.		IP address or an anycast IP address that may not be globally unique.
	Additionally, an entity such as a PID may have an identifier that is		Additionally, an entity such as a PID may have an identifier that is
	not globally unique. That is, a same PID may be used in multiple		not globally unique. That is, the same PID may be used in multiple
	network maps, while in each network map, this PID points to a		network maps, while in each network map, this PID points to a
	different set of addresses.		different set of addresses.
	Third, in section 11.4 of [RFC7285], the EPS is only defined as a		Third, in Section 11.4 of [RFC7285], the EPS is only defined as a
	POST-mode service. ALTO clients must request the properties for an		POST-mode service. ALTO clients must request the properties for an
	explicit set of endpoint addresses. By contrast, [RFC7285], in		explicit set of endpoint addresses. By contrast, Section 11.2.3 of
	section 11.2.3, defines a GET-mode cost map resource which returns		[RFC7285] defines a GET-mode cost map resource that returns all
	all available costs, so an ALTO Client can retrieve a full set of		available costs, so an ALTO Client can retrieve a full set of costs
	costs once, and then process cost lookups without querying the ALTO		once and then process cost lookups without querying the ALTO server.
	server. [RFC7285] does not define a similar service for endpoint		[RFC7285] does not define a similar service for endpoint properties.
	properties. At first, a map of endpoint properties might seem		At first, a map of endpoint properties might seem impractical because
	impractical, because it could require enumerating the property value		it could require enumerating the property value for every possible
	for every possible endpoint. In particular, the number of endpoint		endpoint. In particular, the number of endpoint addresses involved
	addresses involved by an ALTO server can be quite large. To avoid		by an ALTO server can be quite large. To avoid enumerating a large
	enumerating a large number of endpoint addresses inefficiently, the		number of endpoint addresses inefficiently, the ALTO server might
	ALTO server might define properties for a sufficiently large subset		define properties for a sufficiently large subset of endpoints and
	of endpoints and uses an aggregation representation to reference		then use an aggregation representation to reference endpoints in
	endpoints to allow efficient enumeration. This is particularly true		order to allow efficient enumeration. This is particularly true if
	if blocks of endpoint addresses with a common prefix have the same		blocks of endpoint addresses with a common prefix have the same value
	value for a property. Entities in other domains may very well allow		for a property. Entities in other domains may very well allow
	aggregated representation and hence be enumerable as well.		aggregated representation and hence be enumerable as well.
	To address these three limitations, this document specifies an ALTO		To address these three limitations, this document specifies an ALTO
	protocol extension for defining and retrieving ALTO properties:		Protocol extension for defining and retrieving ALTO properties:
	* The first limitation is addressed by introducing a generic concept		* The first limitation is addressed by introducing a generic concept
	called ALTO Entity, which generalizes an endpoint and may		called ALTO entity, which generalizes an endpoint and may
	represent a PID, a network element, a cell in a cellular network,		represent a PID, a network element, a cell in a cellular network,
	an abstracted network element [I-D.ietf-alto-path-vector], or		an Abstract Network Element [PATH-VECTOR], or other physical or
	other physical or logical objects involved in a network topology.		logical objects involved in a network topology. Each entity is
	Each entity is included in a collection called an ALTO entity		included in a collection called an ALTO entity domain. Since each
	domain. Since each ALTO entity domain includes only one type of		ALTO entity domain includes only one type of entity, each entity
	entities, each entity domain can be classified by the type of		domain can be classified by the type of enclosed entities.
	enclosed entities.
	* The second limitation is addressed by using resource-specific		* The second limitation is addressed by using resource-specific
	entity domains. A resource-specific entity domain contains		entity domains. A resource-specific entity domain contains
	entities that are defined and identified with respect to a given		entities that are defined and identified with respect to a given
	ALTO information resource, which provides scoping. For example,		ALTO information resource, which provides scoping. For example,
	an entity domain containing PIDs is identified with respect to the		an entity domain containing PIDs is identified with respect to the
	network map in which these PIDs are defined. Likewise, an entity		network map in which these PIDs are defined. Likewise, an entity
	domain containing local IP addresses may be defined with respect		domain containing local IP addresses may be defined with respect
	to a local network map.		to a local network map.
	* The third limitation is addressed by defining two new types of		* The third limitation is addressed by defining two new types of
	ALTO information resources: Property Map (Section 7) and Filtered		ALTO information resources: property map (Section 7) and filtered
	Property Map (Section 8). The former is a resource that is		property map (Section 8). The former is a resource that is
	requested using the HTTP GET method, returns the property values		requested using the HTTP GET method, returns the property values
	for all entities in one or more entity domains, and is analogous		for all entities in one or more entity domains, and is analogous
	to a network map or a cost map in Section 11.2 of [RFC7285]. The		to a network map or a cost map in Section 11.2 of [RFC7285]. The
	latter is a resource that that is requested using the HTTP POST		latter is a resource that is requested using the HTTP POST method,
	method, returns the values for sets of properties and entities		returns the values for sets of properties and entities requested
	requested by the client, and is analogous to a filtered network		by the client, and is analogous to a filtered network map or a
	map or a filtered cost map.		filtered cost map.
	The Entity Property Maps extension described in this document		The entity property maps extension described in this document
	introduces a number of features that are summarized in Appendix A,		introduces a number of features that are summarized in Appendix A,
	where Table 4 lists the features and references the sections in this		where Table 11 lists the features and references the sections in this
	document that give their high-level and their normative description.		document that give their high-level and their normative descriptions.
	The protocol extension defined in this document is augmentable. New		The protocol extension defined in this document can be augmented.
	entity domain types can be defined without revising the present		New entity domain types can be defined without revising the present
	specification. Similarly, new cost metrics and new endpoint		specification. Similarly, new cost metrics and new endpoint
	properties can be defined in other documents without revising the		properties can be defined in other documents without revising the
	protocol specification defined in [RFC7285].		protocol specification defined in [RFC7285].
	1.1. Terminology and notation		1.1. Terminology and Notation
	This document uses the following terms and abbreviations, that will		This document uses the following terms and abbreviations that will be
	be further defined in the document. While this document introduces		further defined in the document. While this document introduces the
	the feature "entity property map", it will use both the term		feature "entity property map", it will use both the term "property
	"property map" and "entity property map" to refer to this feature.		map" and "entity property map" to refer to this feature.
	* Transaction: A request/response exchange between an ALTO client		Transaction: A request/response exchange between an ALTO client and
	and an ALTO server.		an ALTO server.
	* Client: When used with a capital "C", this term refers to an ALTO		Client: When used with a capital "C", this term refers to an ALTO
	client. Note that expressions "ALTO client", "ALTO Client" and		client. Note that expressions "ALTO client", "ALTO Client", and
	"Client" are equivalent.		"Client" are equivalent.
	* Server: When used with a capital "S", this term refers to an ALTO		Server: When used with a capital "S", this term refers to an ALTO
	server. Note that expressions "ALTO server", "ALTO Server" and		server. Note that expressions "ALTO server", "ALTO Server", and
	"Server" are equivalent.		"Server" are equivalent.
	* EPS: An abbreviation for Endpoint Property Service.		EPS: An abbreviation for Endpoint Property Service.
	This document uses the semi-formal notation defined in Section 8.2 of		This document uses the notation defined in Section 8.2 of [RFC7285].
	[RFC7285].
	2. Requirements Language		2. Requirements Language
	The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",		The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
	"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and		"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
	"OPTIONAL" in this document are to be interpreted as described in BCP		"OPTIONAL" in this document are to be interpreted as described in
	14 [RFC2119] [RFC8174] when, and only when, they appear in all		BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
	capitals, as shown here. When the words appear in lower case, they		capitals, as shown here.
	are to be interpreted with their natural language meanings.
	3. Basic Features of the Entity Property Map Extension		3. Basic Features of the Entity Property Map Extension
	This section gives a high-level overview of the basic features		This section gives a high-level overview of the basic features
	involved in ALTO Entity Property Maps. It assumes the reader is		involved in ALTO entity property maps. It assumes the reader is
	familiar with the ALTO protocol [RFC7285]. The purpose of this		familiar with the ALTO Protocol [RFC7285]. The purpose of this
	extension is to convey properties on objects that extend ALTO		extension is to convey properties for objects that extend ALTO
	Endpoints and are called ALTO Entities, or entities for short.		endpoints and are called ALTO Entities, or entities for short.
	The features introduced in this section can be used as standalone.		The features introduced in this section can be used standalone.
	However, in some cases, these features may depend on particular		However, in some cases, these features may depend on particular
	information resources and need to be defined with respect to them.		information resources and need to be defined with respect to them.
	To this end, Section 4 introduces additional features that extend the		To this end, Section 4 introduces additional features that extend the
	ones presented in the present section.		ones presented in this section.
	3.1. Entity		3.1. Entity
	The concept of an ALTO Entity generalizes the concept of an ALTO		The concept of an ALTO entity generalizes the concept of an ALTO
	Endpoint defined in Section 2.1 of [RFC7285]. An entity is an object		endpoint defined in Section 2.1 of [RFC7285]. An entity is an object
	that can be an endpoint defined by its network address, but can also		that can be an endpoint defined by its network address, but it can
	be an object that has a defined mapping to a set of one or more		also be an object that has a defined mapping to a set of one or more
	network addresses or an object that is not even related to any		network addresses or an object that is not even related to any
	network address. Thus, whereas all endpoints are entities, not all		network address. Thus, whereas all endpoints are entities, not all
	entities are endpoints.		entities are endpoints.
	Examples of entities are:		Examples of entities are:
	* an ALTO endpoint that represents an application or a host		* an ALTO endpoint that represents an application or a host
	identified by a communication address (e.g., an IPv4 or IPv6		identified by a communication address (e.g., an IPv4 or IPv6
	address) in a network,		address) in a network,
	* a PID, defined in [RFC7285], that has a provider defined human-		* a PID, defined in [RFC7285], that has a provider-defined, human-
	readable identifier specified by an ALTO network map, which maps a		readable identifier specified by an ALTO network map, which maps a
	PID to a set of IPv4 and IPv6 addresses,		PID to a set of IPv4 and IPv6 addresses,
	* an Autonomous System (AS), that has an AS number (ASN) as its		* an Autonomous System (AS) that has an AS number (ASN) as its
	identifier and maps to a set of IPv4 and IPv6 addresses, that is		identifier and maps to a set of IPv4 and IPv6 addresses, which is
	defined in [I-D.ietf-alto-cdni-request-routing-alto],		defined in [RFC9241],
	* a country with a code specified in [ISO3166-1], to which		* a country with a code specified in [ISO3166-1] to which
	applications such as CDN providers associate properties and		applications such as content delivery network (CDN) providers
	capabilities, that is defined in		associate properties and capabilities, which is defined in
	[I-D.ietf-alto-cdni-request-routing-alto],		[RFC9241],
	* a TCP/UDP network flow, that is identified by a TCP/UDP 5-tuple		* a TCP or UDP network flow that is identified by a 5-tuple
	specifying its source and destination addresses and port numbers,		specifying its source and destination addresses and port numbers,
	and the IP protocol,		and the IP protocol (TCP or UDP),
	* a routing element, that is specified in [RFC7921] and is		* a routing element, as specified in [RFC7921], that is associated
	associated with routing capabilities information,		with routing capabilities information, or
	* an abstract network element, that is specified in		* an Abstract Network Element, as specified in [PATH-VECTOR], that
	[I-D.ietf-alto-path-vector] and that represents an abstraction of		represents an abstraction of a network part such as a router, one
	a network part such as a router, one or more links, a network		or more links, a network domain, or their aggregation.
	domain or their aggregation.
	Some of the example entities listed above have already been		Some of the example entities listed above have already been
	documented as ALTO entities. The other examples are provided for		documented as ALTO entities. The other examples are provided for
	illustration as potential entities.		illustration as potential entities.
	3.2. Entity Domain		3.2. Entity Domain
	An entity domain defines a set of entities of the same semantic type.		An entity domain defines a set of entities of the same semantic type.
	An entity domain is characterized by a type and identified by a name.		An entity domain is characterized by a type and identified by a name.
	In this document, an entity is owned by exactly one entity domain		In this document, an entity is owned by exactly one entity domain
	name. An entity identifier points to exactly one entity. If two		name. An entity identifier points to exactly one entity. If two
	entities in two different entity domains refer to the same physical		entities in two different entity domains refer to the same physical
	or logical object, they are treated as different entities. For		or logical object, they are treated as different entities. For
	example, if an end host has both an IPv4 and an IPv6 address, these		example, if an end host has both an IPv4 and an IPv6 address, these
	two addresses will be treated as two entities, defined respectively		two addresses will be treated as two entities, defined respectively
	in the "ipv4" and "ipv6" entity domains.		in the "ipv4" and "ipv6" entity domains.
	3.2.1. Entity Domain Type		3.2.1. Entity Domain Type
	The type of an entity domain type defines the semantics of a type of		The entity domain type defines the semantics of the type of entity
	entity. Entity domain types can be defined in different documents.		found in an entity domain. Entity domain types can be defined in
	For example: the present document defines entity domain types "ipv4",		different documents. For example: the present document defines
	"ipv6" and "pid" in Section 6.1 and Section 6.2. The entity domain		entity domain types "ipv4" and "ipv6" in Section 6.1 and "pid" in
	type "ane", that defines Abstract Network Elements (ANEs), is		Section 6.2. The entity domain type "ane", which defines Abstract
	introduced in [I-D.ietf-alto-path-vector]. The entity domain type		Network Elements (ANEs), is introduced in [PATH-VECTOR]. The
	that defines country codes is introduced in		"countrycode" entity domain type that defines country codes is
	[I-D.ietf-alto-cdni-request-routing-alto]. An entity domain type		introduced in [RFC9241]. An entity domain type MUST be registered
	MUST be registered at the IANA, as specified in Section 12.3.2.		with IANA, as specified in Section 12.3.2.
	3.2.2. Entity Domain Name		3.2.2. Entity Domain Name
	In this document, the identifier of an entity domain is mostly called		In this document, the identifier of an entity domain is mostly called
	"entity domain name". The identifier of an entity domain is defined		"entity domain name". The identifier of an entity domain is scoped
	in the scope of an ALTO server. An entity domain identifier can		to an ALTO server. An entity domain identifier can sometimes be
	sometimes be identical to the identifier of its relevant entity		identical to the identifier of its relevant entity domain type. This
	domain type. This is the case when the entities of a domain have an		is the case when the entities of a domain have an identifier that
	identifier that points to the same object throughout all the		points to the same object throughout all the information resources of
	information resources of the Server that provide entity properties		the Server that are providing entity properties for this domain. For
	for this domain. For example, a domain of type "ipv4" containing		example, a domain of type "ipv4" containing entities that are
	entities that are identified by a public IPv4 address can be named		identified by a public IPv4 address can be named "ipv4" because its
	"ipv4" because its entities are uniquely identified by all the Server		entities are uniquely identified by all the Server resources.
	resources.
	In some cases, the name of an entity domain cannot be simply its		In some cases, the name of an entity domain cannot be simply its
	entity domain type. Indeed, for some domain types, entities are		entity domain type. Indeed, for some domain types, entities are
	defined relative to a given information resource. This is the case		defined relative to a given information resource. This is the case
	for entities of domain type "pid". A PID is defined relative to a		for entities of domain type "pid". A PID is defined relative to a
	network map. For example, an entity "mypid10" of domain type "pid"		network map. For example, an entity "mypid10" of domain type "pid"
	may be defined in a given network map and be undefined in other		may be defined in a given network map and be undefined in other
	network maps. Or "mypid10" may even be defined in two different		network maps. The entity "mypid10" may even be defined in two
	network maps and map, in each of these network maps, to a different		different network maps, and it may map in each of these network maps
	set of endpoint addresses. In this case, naming an entity domain		to a different set of endpoint addresses. In this case, naming an
	only by its type "pid" does not guarantee that its set of entities is		entity domain only by its type "pid" does not guarantee that its set
	owned by exactly one entity domain.		of entities is owned by exactly one entity domain.
	Section 4.2 and Section 5.1.2 describe how a domain is uniquely		Sections 4.2 and 5.1.2 describe how a domain is uniquely identified
	identified, across the ALTO server, by a name that associates the		across the ALTO server by a name that associates the domain type and
	domain type and the related information resource.		the related information resource.
	3.3. Entity Property Type		3.3. Entity Property Type
	An entity property defines a property of an entity. This is similar		An entity property defines a property of an entity. This is similar
	to the endpoint property defined in Section 7.1 of [RFC7285]. An		to the endpoint property defined in Section 7.1 of [RFC7285]. An
	entity property can convey either network-aware or network-agnostic		entity property can convey either network-aware or network-agnostic
	information. Similar to an entity domain, an entity property is		information. Similar to an entity domain, an entity property is
	characterized by a type and identified by a name. An entity property		characterized by a type and identified by a name. An entity property
	type MUST be registered at the IANA, as specified in Section 12.4.		type MUST be registered with IANA, as specified in Section 12.4.
	Below are listed some examples with real and fictitious entity domain		Below are listed some examples with real and fictitious entity domain
	and property names:		and property names:
	* an entity in the "ipv4" domain type may have a property whose		* an entity in the "ipv4" domain type may have a property whose
	value is an Autonomous System (AS) number indicating the AS to		value is an Autonomous System (AS) number indicating the AS to
	which this IPv4 address belongs and another property named		which this IPv4 address belongs and another property named
	"countrycode" indicating a country code mapping to this address,		"countrycode" indicating a country code mapping to this address,
	* an entity identified by its country code in the entity domain type		* an entity identified by its country code in the entity domain type
	"countrycode", defined in		"countrycode", defined in [RFC9241], may have a property
	[I-D.ietf-alto-cdni-request-routing-alto] may have a property		indicating what delivery protocol is used by a CDN, or
	indicating what delivery protocol is used by a CDN,
	* an entity in the "netmap1.pid" domain may have a property that		* an entity in the "netmap1.pid" domain may have a property that
	indicates the central geographical location of the endpoints it		indicates the central geographical location of the endpoints it
	includes.		includes.
	It should be noted that some identifiers may be used for both an		It should be noted that some identifiers may be used for both an
	entity domain type and a property type. For example:		entity domain type and a property type. For example:
	* the identifier "countrycode" may point to both the entity domain		* the identifier "countrycode" may point to both the entity domain
	type "countrycode" and the fictitious property type "countrycode".		type "countrycode" and the fictitious property type "countrycode".
	* the identifier "pid" may point to both the entity domain type		* the identifier "pid" may point to both the entity domain type
	"pid" and the property type "pid".		"pid" and the property type "pid".
	Likewise, the same identifier may point to both a domain name and a		Likewise, the same identifier may point to both a domain name and a
	property name. For example: the identifier "netmap10.pid" may point		property name. For example: the identifier "netmap10.pid" may point
	to either the domain defined by the PIDs of network map "netmap10" or		to either the domain defined by the PIDs of network map "netmap10" or
	to a property that returns, for an entity defined by its IPv4		to a property that returns, for an entity defined by its IPv4
	address, the PID of netmap10 that contains this entity. Such cases		address, the PID of "netmap10" that contains this entity. Such cases
	will be further explained in Section 4.		are further explained in Section 4.
	3.4. New Information Resource and Media Type: ALTO Property Map		3.4. New Information Resource and Media Type: ALTO Property Map
	This document introduces a new ALTO information resource named		This document introduces a new ALTO information resource named
	Property Map. An ALTO property map provides a set of properties on		property map. An ALTO property map provides a set of properties for
	one or more sets of entities. A property may apply to different		one or more sets of entities. A property may apply to different
	entity domain types and names. For example, an ALTO property map may		entity domain types and names. For example, an ALTO property map may
	define the "ASN" property for both "ipv4" and "ipv6" entity domains.		define the "ASN" property for both "ipv4" and "ipv6" entity domains.
	The present extension also introduces a new media type.		The present extension also introduces a new media type.
	This document uses the same definition of an information resource as		This document uses the same definition of an information resource as
	Section 9.1 of [RFC7285]. ALTO uses media types to uniquely indicate		Section 9.1 of [RFC7285]. ALTO uses media types to uniquely indicate
	the data format used to encode the content to be transmitted between		the data format used to encode the content to be transmitted between
	an ALTO server and an ALTO client in the HTTP entity body. In the		an ALTO server and an ALTO client in the HTTP entity body. In the
	present case, an ALTO property map resource is defined by the media		present case, an ALTO property map resource is defined by the media
	type "application/alto-propmap+json".		type "application/alto-propmap+json".
	A Property Map can be queried as a GET-mode resource, thus conveying		A property map can be queried as a GET-mode resource, thus conveying
	all properties on all entities indicated in its capabilities. It can		all properties for all entities indicated in its capabilities. It
	also be queried as a POST-mode resource, thus conveying a selection		can also be queried as a POST-mode resource, thus conveying a
	of properties on a selection of entities.		selection of properties for a selection of entities.
	4. Advanced Features of the Entity Property Map Extension		4. Advanced Features of the Entity Property Map Extension
	This section gives a high-level overview of the advanced features		This section gives a high-level overview of the advanced features
	involved in ALTO Entity Property Maps. Most of these features are		involved in ALTO entity property maps. Most of these features extend
	defined to extend the ones defined in Section 3.		the features defined in Section 3.
	4.1. Entity Identifier and Entity Domain Name		4.1. Entity Identifier and Entity Domain Name
	In [RFC7285], an endpoint has an identifier that is explicitly		In [RFC7285], an endpoint has an identifier that is explicitly
	associated with the "ipv4" or "ipv6" address domain. Examples are		associated with the "ipv4" or "ipv6" address domain. Examples are
	"ipv4:192.0.2.14" and "ipv6:2001:db8::12".		"ipv4:192.0.2.14" and "ipv6:2001:db8::12".
	In this document, example IPv4 and IPv6 addresses and prefixes are		In this document, example IPv4 and IPv6 addresses and prefixes are
	taken from the address ranges reserved for documentation by [RFC5737]		taken from the address ranges reserved for documentation by [RFC5737]
	and [RFC3849].		and [RFC3849].
	In this document, an entity must be owned by exactly one entity		In this document, an entity must be owned by exactly one entity
	domain name and an entity identifier must point to exactly one		domain name, and an entity identifier must point to exactly one
	entity. To ensure this, an entity identifier is explicitly attached		entity. To ensure this, an entity identifier is explicitly attached
	to the name of its entity domain and an entity domain type		to the name of its entity domain, and an entity domain type
	characterizes the semantics and identifier format of its entities.		characterizes the semantics and identifier format of its entities.
	The encoding format of an entity identifier is further specified in		The encoding format of an entity identifier is further specified in
	Section 5.1.3 of this document.		Section 5.1.3 of this document.
	For instance:		For instance:
	* if an entity is an endpoint with IPv4 address "192.0.2.14", its		* if an entity is an endpoint with IPv4 address "192.0.2.14", its
	identifier is associated with entity domain name "ipv4" and is		identifier is associated with entity domain name "ipv4" and is
	"ipv4:192.0.2.14",		"ipv4:192.0.2.14";
	* if an entity is a PID named "mypid10" in network map resource		* if an entity is a PID named "mypid10" in network map resource
	"netmap2", its identifier is associated with entity domain name		"netmap2", its identifier is associated with entity domain name
	"netmap2.pid" and is "netmap2.pid:mypid10".		"netmap2.pid" and is "netmap2.pid:mypid10".
	4.2. Resource-Specific Entity Domain Name		4.2. Resource-Specific Entity Domain Name
	Some entities are defined and identified uniquely and globally in the		Some entities are defined and identified uniquely and globally in the
	context of an ALTO server. This is the case for instance when		context of an ALTO server. This is the case, for instance, when
	entities are endpoints that are identified by a reachable IPv4 or		entities are endpoints that are identified by a reachable IPv4 or
	IPv6 address. The entity domain for such entities can be globally		IPv6 address. The entity domain for such entities can be globally
	defined and named "ipv4" or "ipv6". Those entity domains are called		defined and named "ipv4" or "ipv6". Those entity domains are called
	resource-agnostic entity domains in this document, as they are not		resource-agnostic entity domains in this document, as they are not
	associated with any specific ALTO information resources.		associated with any specific ALTO information resources.
	Some other entities and entity types are only defined relative to a		Some other entities and entity types are only defined relative to a
	given information resource. This is the case for entities of domain		given information resource. This is the case for entities of domain
	type "pid", that can only be understood with respect to the network		type "pid", which can only be understood with respect to the network
	map where they are defined. For example, a PID named "mypid10" may		map where they are defined. For example, a PID named "mypid10" may
	be defined to represent a set S1 of IP addresses in a network map		be defined to represent a set S1 of IP addresses in a network map
	resource named "netmap1". Another network map "netmap2" may use the		resource named "netmap1". Another network map "netmap2" may use the
	same name "mypid10" and define it to represent another set S2 of IP		same name "mypid10" and define it to represent another set S2 of IP
	addresses. The identifier "pid:mypid10" may thus point to different		addresses. The identifier "pid:mypid10" may thus point to different
	objects because the information on the originating information		objects because the information on the originating information
	resource is lost.		resource is lost.
	To solve this ambiguity, the present extension introduces the concept		To solve this ambiguity, the present extension introduces the concept
	of resources-specific entity domain. This concept applies to domain		of resource-specific entity domain. This concept applies to domain
	types where entities are defined relative to a given information		types where entities are defined relative to a given information
	resource. It can also apply to entity domains that are defined		resource. It can also apply to entity domains that are defined
	locally, such as local networks of objects identified with a local		locally, such as local networks of objects identified with a local
	IPv4 address.		IPv4 address.
	In such cases, an entity domain type is explicitly associated with an		In such cases, an entity domain type is explicitly associated with an
	identifier of the information resource where these entities are		identifier of the information resource where these entities are
	defined. Such an information resource is referred to as the		defined. Such an information resource is referred to as the
	"specific information resource". Using a resource-aware entity		"specific information resource". Using a resource-aware entity
	domain name, an ALTO property map can unambiguously identify distinct		domain name, an ALTO property map can unambiguously identify distinct
	entity domains of the same type, on which entity properties may be		entity domains of the same type, on which entity properties may be
	queried. Examples of resource-specific entity domain names may look		queried. Examples of resource-specific entity domain names may look
	like: "netmap1.pid" or "netmap2.pid". Thus, a name association such		like "netmap1.pid" or "netmap2.pid". Thus, a name association such
	as "netmap1.pid:mypid10" and "netmap2.pid:mypid10" allows to		as "netmap1.pid:mypid10" and "netmap2.pid:mypid10" distinguishes the
	distinguish the two abovementioned PIDs that are both named "mypid10"		two abovementioned PIDs that are both named "mypid10" but in two
	but in two different resources, "netmap1" and "netmap2".		different resources, "netmap1" and "netmap2".
	An information resource is defined in the scope of an ALTO Server and		An information resource is defined in the scope of an ALTO Server and
	so is an entity domain name. The format of a resource-specific		so is an entity domain name. The format of a resource-specific
	entity domain name is further specified in Section 5.1.2.		entity domain name is further specified in Section 5.1.2.
	4.3. Resource-Specific Entity Property Value		4.3. Resource-Specific Entity Property Value
	Like entity domains, some types of properties are defined relative to		Like entity domains, some types of properties are defined relative to
	an information resource. That is, an entity may have a property of a		an information resource. That is, an entity may have a property of a
	given type, whose values are associated to different information		given type whose values are associated with different information
	resources.		resources.
	For example, suppose entity "192.0.2.34" defined in the "ipv4" domain		For example, suppose entity "192.0.2.34" defined in the "ipv4" domain
	has a property of type "pid", whose value is the PID to which address		has a property of type "pid" whose value is the PID to which address
	"192.0.2.34" is attached in a network map. The mapping of network		"192.0.2.34" is attached in a network map. The mapping of network
	addresses to PIDs is specific to a network map and probably different		addresses to PIDs is specific to a network map and probably different
	from one network map resource to another one. Thus, if a property		from one network map resource to another one. Thus, if a property
	"pid" is defined for entity "192.0.2.34" in two different network		"pid" is defined for entity "192.0.2.34" in two different network
	maps "netmap1" and "netmap2", the value for this property can be a		maps "netmap1" and "netmap2", the value for this property can be a
	different value in "netmap1" and "netmap2".		different value in "netmap1" and "netmap2".
	To support information resource dependent property values, this		To support information-resource-dependent property values, this
	document uses the same approach as in Section 10.8.1 of [RFC7285]		document uses the same approach as in Section 10.8.1
	entitled "Resource-Specific Endpoint Properties". When a property		("Resource-Specific Endpoint Properties") of [RFC7285]. When a
	value depends on a given information resource, the name of this		property value depends on a given information resource, the name of
	property MUST be explicitly associated with the information resource		this property MUST be explicitly associated with the information
	that defines it.		resource that defines it.
	For example, the property "pid" queried on entity "ipv4:192.0.2.34"		For example, the property "pid" queried on entity "ipv4:192.0.2.34"
	and defined in both "netmap1" and "netmap2", can be named		and defined in both "netmap1" and "netmap2" can be named
	"netmap1.pid" and "netmap2.pid". This allows a Client to get a		"netmap1.pid" and "netmap2.pid". This allows a Client to get a
	property of the same type but defined in different information		property of the same type but defined in different information
	resources with a single query. Specifications on the property name		resources with a single query. Specifications for the property name
	format are provided in Section 5.2.		format are provided in Section 5.2.
	4.4. Entity Hierarchy and Property Inheritance		4.4. Entity Hierarchy and Property Inheritance
	For some domain types, there is an underlying structure that allows		For some domain types, there is an underlying structure that allows
	entities to efficiently be grouped into a set and be defined by the		entities to be efficiently grouped into a set and be defined by the
	identifier of this set. This is the case for domain types "ipv4" and		identifier of this set. This is the case for domain types "ipv4" and
	"ipv6", where individual Internet addresses can be grouped in blocks.		"ipv6", where individual Internet addresses can be grouped in blocks.
	When the same property value applies to a whole set, a Server can		When the same property value applies to a whole set, a Server can
	define a property for the identifier of this set instead of		define a property for the identifier of this set instead of
	enumerating all the entities and their properties. This allows a		enumerating all the entities and their properties. This allows a
	substantial reduction of transmission payload both for the Server and		substantial reduction of transmission payload both for the Server and
	the Client. For example, all the entities included in the set		the Client. For example, all the entities included in the set
	defined by the address block "ipv6:2001:db8::1/64" share the same		defined by the address block "ipv6:2001:db8::1/64" share the same
	properties and values defined for this block.		properties and values defined for this block.
	Additionally, entity sets sometimes are related by inclusion,		Additionally, entity sets sometimes are related by inclusion,
	hierarchy or other relations. This allows defining inheritance rules		hierarchy, or other relations. This allows defining inheritance
	for entity properties that propagate properties among related entity		rules for entity properties that propagate properties among related
	sets. The Server and the Client can use these inheritance rules for		entity sets. The Server and the Client can use these inheritance
	further payload savings. Entity hierarchy and property inheritance		rules for further payload savings. Entity hierarchy and property
	rules are specified in the documents that define the applicable		inheritance rules are specified in the documents that define the
	domain types. The present document defines these rules for the		applicable domain types. The present document defines these rules
	"ipv4" and "ipv6" domain types.		for the "ipv4" and "ipv6" domain types.
	This document introduces, for applicable domain types, "Entity		For applicable domain types, this document introduces entity property
	Property Inheritance rules", with the following concepts: Entity		inheritance rules with the following concepts: entity hierarchy,
	Hierarchy, Property Inheritance and Property Value Unicity. A		property inheritance, and property value unicity. A detailed
	detailed specification of entity hierarchy and property inheritance		specification of entity hierarchy and property inheritance rules is
	rules is provided in Section 5.1.4.		provided in Section 5.1.4.
	4.4.1. Entity Hierarchy		4.4.1. Entity Hierarchy
	An entity domain may allow using a single identifier to identify a		An entity domain may allow the use of a single identifier to identify
	set of related individual entities. For example, a CIDR block can be		a set of related individual entities. For example, a Classless
	used to identify a set of IPv4 or IPv6 entities. A CIDR block is		Inter-Domain Routing (CIDR) block can be used to identify a set of
	called a hierarchical entity identifier, as it can reflect inclusion		IPv4 or IPv6 entities. A CIDR block is called a hierarchical entity
	relations among entity sets. That is, in an entity hierarchy,		identifier, as it can reflect inclusion relations among entity sets.
	"supersets" are defined at upper levels and include "subsets" defined		That is, in an entity hierarchy, "supersets" are defined at upper
	at lower levels." For example, the CIDR "ipv4:192.0.1.0/24" includes		levels and include "subsets" defined at lower levels. For example,
	all the individual IPv4 entities identified by the CIDR		the CIDR "ipv4:192.0.1.0/24" includes all the individual IPv4
	"ipv4:192.0.1.0/26". This document will sometimes use the term		entities identified by the CIDR "ipv4:192.0.1.0/26". This document
	"hierarchical address" to refer to a hierarchical entity identifier.		will sometimes use the term "hierarchical address" to refer to a
			hierarchical entity identifier.
	4.4.2. Property Inheritance		4.4.2. Property Inheritance
	A property may be defined for a hierarchical entity identifier, while		A property may be defined for a hierarchical entity identifier, while
	it may be undefined for individual entities covered by this		it may be undefined for individual entities covered by this
	identifier. In this case, these individual entities inherit the		identifier. In this case, these individual entities inherit the
	property value defined for the identifier that covers them. For		property value defined for the identifier that covers them. For
	example, suppose a property map defines a property P for which it		example, suppose a property map defines a property P for which it
	assigns value V1 only for the hierarchical entity identifier		assigns value V1 only for the hierarchical entity identifier
	"ipv4:192.0.1.0/24" but not for individual entities in this block.		"ipv4:192.0.1.0/24" but not for individual entities in this block.
	skipping to change at page 14, line 29 ¶		skipping to change at line 632 ¶
	Property value inheritance rules also apply among entity sets. A		Property value inheritance rules also apply among entity sets. A
	property map may define values for an entity set belonging to a		property map may define values for an entity set belonging to a
	hierarchy but not for "subsets" that are covered by this set		hierarchy but not for "subsets" that are covered by this set
	identifier. In this case, inheritance rules must specify how		identifier. In this case, inheritance rules must specify how
	entities in "subsets" inherit property values from their "superset".		entities in "subsets" inherit property values from their "superset".
	For instance, suppose a property P is defined only for the entity set		For instance, suppose a property P is defined only for the entity set
	defined by address block "ipv4:192.0.1.0/24". We know that entity		defined by address block "ipv4:192.0.1.0/24". We know that entity
	set "ipv4:192.0.1.0/30" is included in "ipv4:192.0.1.0/24".		set "ipv4:192.0.1.0/30" is included in "ipv4:192.0.1.0/24".
	Therefore, the entities of "ipv4:192.0.1.0/30" may inherit the value		Therefore, the entities of "ipv4:192.0.1.0/30" may inherit the value
	of property P from set "ipv4:192.0.1.0/24", if an inheritance rule		of property P from set "ipv4:192.0.1.0/24" if an inheritance rule
	from "ipv4" CIDR blocks to included "ipv4" CIDR blocks, is specified.		from "ipv4" CIDR blocks to included "ipv4" CIDR blocks is specified.
	4.4.3. Property Value Unicity		4.4.3. Property Value Unicity
	The inheritance rules must ensure that an entity belonging to a		The inheritance rules must ensure that an entity belonging to a
	hierarchical set of entities inherits no more than one property		hierarchical set of entities inherits no more than one property
	value, for the sake of consistency. Indeed, a property map may		value, for the sake of consistency. Indeed, a property map may
	define a property on a hierarchy of entity sets that inherit property		define a property for a hierarchy of entity sets that inherits
	values from one or more supersets (located at upper levels). On the		property values from one or more supersets (located at upper levels).
	other hand, a property value, defined on a subset (located at a lower		On the other hand, a property value defined for a subset (located at
	level) may be different from the value defined on a superset. In		a lower level) may be different from the value defined for a
	such a case, subsets may potentially end up with different property		superset. In such a case, subsets may potentially end up with
	values. This may be the case for address blocs with increasing		different property values. This may be the case for address blocks
	prefix length, on which a property value gets increasingly accurate		with increasing prefix length, on which a property value becomes
	and thus may differ. For example, a fictitious property such as		increasingly accurate and thus may differ. For example, a fictitious
	"geo-location" or "average transfer volume" may be defined at a		property such as "geo-location" or "average transfer volume" may be
	progressively finer grain for lower level subsets of entities,		defined at a progressively finer grain for lower-level subsets of
	defined with progressively longer CIDR prefixes. It seems more		entities defined with progressively longer CIDR prefixes. It seems
	interesting to have property values of progressively higher accuracy.		more interesting to have property values of progressively higher
	A unicity rule, applied to the entity domain type must specify an		accuracy. A unicity rule applied to the entity domain type must
	arbitration rule among the different property values for an entity.		specify an arbitration rule among the different property values for
	An example illustrating the need for such rules is provided in		an entity. An example illustrating the need for such rules is
	Section 6.1.3.		provided in Section 6.1.3.
	4.5. Supported Properties on Entity Domains in Property Map		4.5. Supported Properties for Entity Domains in Property Map
	Capabilities		Capabilities
	A property type is not necessarily applicable to any domain type, or		A property type is not necessarily applicable to any domain type, or
	an ALTO Server may choose not to provide a property on all applicable		an ALTO Server may choose not to provide a property for all
	domains. For instance, a property type reflecting link bandwidth is		applicable domains. For instance, a property type reflecting link
	likely not defined on entities of a domain of type "countrycode".		bandwidth is likely not defined for entities of a domain of type
	Therefore, an ALTO server providing Property Maps needs to specify		"countrycode". Therefore, an ALTO server providing property maps
	the properties that can be queried on the different entity domains it		needs to specify the properties that can be queried on the different
	supports.		entity domains it supports.
	This document explains how the Information Resources Directory (IRD)		This document explains how the Information Resource Directory (IRD)
	capabilities of a Property Map resource unambiguously expose what		capabilities of a property map resource unambiguously expose which
	properties a Client can query on a given entity domain:		properties a Client can query on a given entity domain:
	* a field named "mappings" lists the names of the entity domains		* a field named "mappings" lists the names of the entity domains
	supported by the Property Map,		supported by the property map, and
	* for each listed entity domain, a list of the names of the		* for each listed entity domain, a list of the names of the
	applicable properties is provided.		applicable properties is provided.
	An example is provided in Section 10.3. The "mappings" field		An example is provided in Section 10.3. The "mappings" field
	associates entity domains and properties that can be resource-		associates entity domains and properties that can be resource-
	agnostic or resource-specific. This allows a Client to formulate		agnostic or resource-specific. This allows a Client to formulate
	compact and unambiguous entity property queries, possibly relating to		compact and unambiguous entity property queries, possibly relating to
	one or more information resources. In particular:		one or more information resources. In particular:
	* it prevents a Client from querying a property on entity domains on		* it prevents a Client from querying a property for entity domains
	which it is not defined,		for which it is not defined;
	* it allows a Client to query, for an entity E, values for a		* it allows a Client to query, for an entity E, values for a
	property P that are defined in several information resources,		property P that are defined in several information resources; and
	* it allows a Client to query a property P on entities that are		* it allows a Client to query a property P on entities that are
	defined in several information resources.		defined in several information resources.
	Further details are provided in Section 7.4.		Further details are provided in Section 7.4.
	4.6. Defining Information Resource for Resource-Specific Entity Domains		4.6. Defining Information Resource for Resource-Specific Entity Domains
	A Client willing to query properties on entities belonging to a		A Client willing to query entity properties belonging to a domain
	domain needs to know how to retrieve these entities. To this end,		needs to know how to retrieve these entities. To this end, the
	the Client can look up the "mappings" field exposed in IRD		Client can look up the "mappings" field exposed in IRD capabilities
	capabilities of a property map, see Section 4.5. This field, in its		of a property map; see Section 4.5. This field, in its keys, exposes
	keys, exposes all the entity domains supported by the property map.		all the entity domains supported by the property map. The syntax of
	The syntax of the entity domain identifier specified in Section 5.1.2		the entity domain identifier specified in Section 5.1.2 allows the
	allows the client to infer whether the entity domain is resource-		client to infer whether the entity domain is resource-specific or
	specific or not. The Client can extract, if applicable, the		not. The Client can extract, if applicable, the identifier of the
	identifier of the specific resource, query the resource and retrieve		specific resource, query the resource, and retrieve the entities.
	the entities. For example:		For example:
	* an entity domain named "netmap1.ipv4" includes the IPv4 addresses		* an entity domain named "netmap1.ipv4" includes the IPv4 addresses
	that appear in the "ipv4" field of the endpoint address group of		that appear in the "ipv4" field of the endpoint address group of
	each PID in the network map "netmap1", and that have no meaning		each PID in the network map "netmap1" and that have no meaning
	outside "netmap1" because, for instance, these are local addresses		outside "netmap1" because, for instance, these are local addresses
	not reachable outside some private network,		not reachable outside some private network;
	* an entity domain named "netmap1.pid" includes the PIDs listed in		* an entity domain named "netmap1.pid" includes the PIDs listed in
	network map "netmap1".		network map "netmap1"; and
	* an entity domain named "ipv4" is resource-agnostic and covers all		* an entity domain named "ipv4" is resource-agnostic and covers all
	the reachable IPv4 addresses.		the reachable IPv4 addresses.
	Besides, it is not possible to prevent a Server from mistakenly		Besides, it is not possible to prevent a Server from mistakenly
	exposing inappropriate associations of information resources and		exposing inappropriate associations of information resources and
	entity domain types. To prevent failures due to invalid queries, it		entity domain types. To prevent failures due to invalid queries, it
	is necessary to inform the Client about which associations are		is necessary to inform the Client which associations are allowed. An
	allowed. An informed Client will just ignore inappropriate		informed Client will just ignore inappropriate associations exposed
	associations exposed by a Server and avoid error-prone transactions		by a Server and avoid error-prone transactions with the Server.
	with the Server.
	For example, the association "costmap3.pid" is not allowed for the		For example, the association "costmap3.pid" is not allowed for the
	following reason: although a cost map exposes PID identifiers, it		following reason: although a cost map exposes PID identifiers, it
	does not define the set of addresses included in this PID. Neither		does not define the set of addresses included in this PID. Neither
	does a cost map list all the PIDs on which properties can be queried,		does a cost map list all the PIDs on which properties can be queried
	because a cost map only exposes PID pairs on which a queried cost		because a cost map only exposes PID pairs on which a queried cost
	type is defined. Therefore, the resource "costmap3" does not enable		type is defined. Therefore, the resource "costmap3" does not enable
	a Client to extract information on the existing PID entities or on		a Client to extract information on the existing PID entities or on
	the addresses they contain.		the addresses they contain.
	Instead, the cost map uses a network map, where all the PIDs used in		Instead, the cost map uses a network map where all the PIDs used in a
	a cost map are defined together with the addresses contained by the		cost map are defined together with the addresses contained by the
	PIDs. This network map is qualified in this document as the Defining		PIDs. This network map is qualified in this document as the defining
	Information Resource for the entity domain of type "pid" and this		information resource for the entity domain of type "pid", and this
	concept is explained in Section 4.6.1.		concept is explained in Section 4.6.1.
	4.6.1. Defining Information Resource and its Media Type		4.6.1. Defining Information Resource and Its Media Type
	For the reasons explained in Section 4.6, this document introduces		For the reasons explained in Section 4.6, this document introduces
	the concept of "Defining Information Resource and its Media Type".		the concept of "Defining Information Resource and its Media Type".
	A defining information resource for an entity domain D is the		A defining information resource for an entity domain D is the
	information resource where entities of D are defined. That is, all		information resource where entities of D are defined. That is, all
	the information on the entities of D can be retrieved in this		the information on the entities of D can be retrieved in this
	resource. A defining information resource is defined for resource-		resource. A defining information resource is defined for resource-
	specific entity domains. It does not exist for entity domains that		specific entity domains. It does not exist for entity domains that
	are not resource-specific such as "ipv4" or "ipv6". Neither does it		are not resource-specific such as "ipv4" or "ipv6". Neither does it
	exist for entity domains that are covering entity identifiers already		exist for entity domains that are covering entity identifiers already
	defined in other standardization documents, at it is the case for		defined in other standardization documents, as is the case for
	country code identifiers standardized in [ISO3166-1] or AS numbers		country code identifiers standardized in [ISO3166-1] or AS numbers
	allocated by the IANA. This is useful for entity domain types that		allocated by IANA. This is useful for entity domain types that are
	are by essence domain-specific, such as the "pid" domain type. It is		by essence domain-specific, such as the domain type "pid". It is
	also useful for resource-specific entity domains constructed from		also useful for resource-specific entity domains constructed from
	resource-agnostic domain types, such as network map specific domains		resource-agnostic domain types, such as network-map-specific domains
	of local IPv4 addresses.		of local IPv4 addresses.
	The defining information resource of a resource-specific entity		The defining information resource of a resource-specific entity
	domain D, when it exists, is unique and has the following		domain D, when it exists, is unique and has the following
	specificities:		characteristics:
	* it has an entry in the IRD,		* it has an entry in the IRD;
	* it defines the entities of D,		* it defines the entities of D;
	* it does not use another information resource that defines these		* it does not use another information resource that defines these
	entities,		entities;
	* it defines and exposes entity identifiers that are all persistent,		* it defines and exposes entity identifiers that are all persistent;
			and
	* its media type is equal to the one that is specified for the		* its media type is equal to the one that is specified for the
	defining information resource of an entity domain type.		defining information resource of an entity domain type.
	A fundamental characteristic of a defining information resource is		A fundamental characteristic of a defining information resource is
	its media type. There is a unique association between an entity		its media type. There is a unique association between an entity
	domain type and the media type of its defining information resource.		domain type and the media type of its defining information resource.
	When an entity domain type allows associations with defining		When an entity domain type allows associations with defining
	information resources, the media type of the potential defining		information resources, the media type of the potential defining
	information resource MUST be specified:		information resource MUST be specified:
	* in the document that defines this entity domain type,		* in the document that defines this entity domain type, and
	* in the IANA ALTO Entity Domain Type Registry and related		* in the "ALTO Entity Domain Types" IANA registry.
	information.
	When the Client wants to use a resource-specific entity domain, it		When the Client wants to use a resource-specific entity domain, it
	needs to be cognizant of the media-type of its defining information		needs to be cognizant of the media type of its defining information
	resource. If the Server exposes a resource-specific entity domain		resource. If the Server exposes a resource-specific entity domain
	with a non-compliant media type for the defining resource, the Client		with a noncompliant media type for the defining resource, the Client
	MUST ignore the entities from that entity domain to avoid errors.		MUST ignore the entities from that entity domain to avoid errors.
	4.6.2. Examples of Defining Information Resources and Their Media Type		4.6.2. Examples of Defining Information Resources and Their Media Types
	Here are examples of defining information resource types and their		Here are examples of defining information resource types and their
	media types associated to different entity domain types:		media types associated with different entity domain types:
	* For entity domain type "pid": the media type of the specific		* For entity domain type "pid", the media type of the specific
	resource is "application/alto-networkmap+json", because PIDs are		resource is "application/alto-networkmap+json" because PIDs are
	defined in network map resources.		defined in network map resources.
	* For entity domain types "ipv4" and "ipv6": the media type of the		* For entity domain types "ipv4" and "ipv6", the media type of the
	specific resource is "application/alto-networkmap+json", because		specific resource is "application/alto-networkmap+json" because
	IPv4 and IPv6 addresses covered by the Server are defined in		IPv4 and IPv6 addresses covered by the Server are defined in
	network map resources.		network map resources.
	* For entities of domain type "ane": [I-D.ietf-alto-path-vector]		* For entities of domain type "ane"; [PATH-VECTOR] defines entities
	defines entities named "ANE", where ANE stands for Abstracted		named "ANE", where ANE stands for Abstract Network Element, and
	Network Element, and the entity domain type "ane". An ANE may		the entity domain type "ane". An ANE may have a persistent
	have a persistent identifier, say, "entity-4", that is provided by		identifier, say, "entity-4", that is provided by the Server as a
	the Server as a value of the "persistent-entity-id" property of		value of the "persistent-entity-id" property of this ANE. Further
	this ANE. Further properties may then be queried on an ANE by		properties may then be queried on an ANE by using its persistent
	using its persistent entity ID. These properties are available		entity identifier. These properties are available from a
	from a persistent property map, that defines properties on a		persistent property map that defines properties for a specific
	specific "ane" domain. Together with the persistent identifier,		"ane" domain. Together with the persistent identifier, the Server
	the Server also provides the property map resource identifier		also provides the property map resource identifier where the "ane"
	where the "ane" domain containing "entity-4" is defined. The		domain containing "entity-4" is defined. The definition of the
	definition of the "ane" entity domain containing "entity-4" is		"ane" entity domain containing "entity-4" is thus specific to the
	thus specific to the property map. Therefore, for entities of		property map. Therefore, for entities of domain type "ane" that
	domain type "ane" that have a persistent identifier, the media		have a persistent identifier, the media type of the defining
	type of the defining information resource is "application/alto-		information resource is "application/alto-propmap+json".
	propmap+json".
	* Last, the entity domain types "asn" and "countrycode" defined in		* Last, the entity domain types "asn" and "countrycode" defined in
	[I-D.ietf-alto-cdni-request-routing-alto] do not have a defining		[RFC9241] do not have a defining information resource. Indeed,
	information resource. Indeed, the entity identifiers in these two		the entity identifiers in these two entity domain types are
	entity domain types are already standardized in documents that the		already standardized in documents that the Client can use.
	Client can use.
	4.7. Defining Information Resource for Resource-Specific Property		4.7. Defining Information Resources for Resource-Specific Property
	Values		Values
	As explained in Section 4.3, a property type may take values that are		As explained in Section 4.3, a property type may take values that are
	resource-specific. This is the case for property type "pid", whose		resource-specific. This is the case for property type "pid", whose
	values are by essence defined relative to a specific network map.		values are by essence defined relative to a specific network map.
	That is, the PID value returned for an IPv4 address is specific to		That is, the PID value returned for an IPv4 address is specific to
	the network map defining this PID and may differ from one network map		the network map defining this PID and may differ from one network map
	to another one.		to another one.
	Another example is provided in		Another example is provided in [RFC9241], which defines property type
	[I-D.ietf-alto-cdni-request-routing-alto] that defines property type
	"cdni-capabilities". The value of this property is specific to a		"cdni-capabilities". The value of this property is specific to a
	CDNI advertisement resource, that provides a list of CDNI		Content Delivery Network Interconnection (CDNI) Advertisement
	capabilities. The property is provided for entity domain types		resource, which provides a list of CDNI capabilities. The property
	"ipv4", "ipv6", "asn" and "countrycode". A CDNI Advertisement		is provided for entity domain types "ipv4", "ipv6", "asn", and
	resource does however not define PID values for IPv4 addresses while		"countrycode". However, a CDNI Advertisement resource does not
	a network map does not define CDNI capabilities for IPv4 addresses.		define PID values for IPv4 addresses, while a network map does not
			define CDNI capabilities for IPv4 addresses.
	Similar to resource-specific entity domains, the Client needs to be		Similar to resource-specific entity domains, the Client needs to be
	cognizant of appropriate associations of information resource and		cognizant of appropriate associations of information resource and
	property types. Therefore, when specifying and registering a		property types. Therefore, when specifying and registering a
	property type whose values are resource-specific, the media type of		property type whose values are resource-specific, the media type of
	its defining information resource needs to be specified. For		its defining information resource needs to be specified. For
	example:		example:
	* The media type of the defining information resource for property		* The media type of the defining information resource for property
	type "pid" is "application/alto-networkmap+json".		type "pid" is "application/alto-networkmap+json".
	* The media type of the defining information resource for property		* The media type of the defining information resource for property
	type "cdni-capabilities" defined in		type "cdni-capabilities" defined in [RFC9241] is "application/
	[I-D.ietf-alto-cdni-request-routing-alto] is "application/alto-		alto-cdni+json".
	cdni+json".
	5. Protocol Specification: Basic Data Types		5. Protocol Specification: Basic Data Types
	5.1. Entity Domain		5.1. Entity Domain
	5.1.1. Entity Domain Type		5.1.1. Entity Domain Type
	An entity domain has a type, which is uniquely identified by a string		An entity domain has a type, which is uniquely identified by a string
	that MUST be no more than 64 characters, and MUST NOT contain		that MUST be no more than 64 characters, and MUST NOT contain
	characters other than US-ASCII alphanumeric characters		characters other than US-ASCII alphanumeric characters
	(U+0030-U+0039, U+0041-U+005A, and U+0061-U+007A), the hyphen ('-',		(U+0030-U+0039, U+0041-U+005A, and U+0061-U+007A), the hyphen-minus
	U+002D), the colon (':', U+003A), or the low line ('_', U+005F).		('-', U+002D), the colon (':', U+003A), or the low line ('_',
			U+005F).
	The usage of colon (':', U+003A) MUST obey the rules below:		The usage of colon (':', U+003A) MUST obey the rules below:
	* The colon (':', U+003A) character MUST NOT appear more than once,		* The colon (':', U+003A) character MUST NOT appear more than once;
	* The colon character MUST NOT be used unless within the string		* The colon character MUST NOT be used unless within the string
	"priv:",		"priv:";
	* The string "priv:" MUST NOT be used unless it starts the string		* The string "priv:" MUST NOT be used unless it starts the string
	that identifies an entity domain type,		that identifies an entity domain type; and
	* For an entity domain type identifier with the "priv:" prefix , an		* For an entity domain type identifier with the "priv:" prefix, an
	additional string (e.g., company identifier or random string) MUST		additional string (e.g., company identifier or random string) MUST
	follow "priv:", to reduce potential collisions.		follow "priv:" to reduce potential collisions.
	For example, the strings "ipv4", "ipv6", "pid" and "priv:example-		For example, the strings "ipv4", "ipv6", "pid", and "priv:example-
	test-edt", are valid entity domain types. "ipv4.anycast", "pid.local"		test-edt", are valid entity domain types. "ipv4.anycast",
	and "priv:" are invalid.		"pid.local", and "priv:" are invalid.
	Although "_", "-", "__--" are valid entity domain types, it is		Although "_", "-", "__--" are valid entity domain types, it is
	desirable to add characters such as alphanumeric ones, for better		desirable to add characters, such as alphanumeric ones, for better
	intelligibility.		intelligibility.
	The type EntityDomainType is used in this document to denote a JSON		The type EntityDomainType is used in this document to denote a JSON
	string meeting the preceding requirements.		string meeting the preceding requirements.
	An entity domain type defines the semantics of a type of entity,		An entity domain type defines the semantics of a type of entity,
	independently of any specifying resource. All entity domain types		independently of any specifying resource. All entity domain types
	that are not prefixed with "priv:" MUST be registered with the IANA,		that are not prefixed with "priv:" MUST be registered with IANA in
	in the "ALTO Entity Domain Type Registry", defined in Section 12.3,		the "ALTO Entity Domain Types" registry, defined in Section 12.3,
	following the procedure specified in Section 12.3.2 of this document.		following the procedure specified in Section 12.3.2 of this document.
	The format of the entity identifiers (see Section 5.1.3) in that		The format of the entity identifiers (see Section 5.1.3) in that
	entity domain type, as well as any hierarchical or inheritance rules		entity domain type, as well as any hierarchical or inheritance rules
	(see Section 5.1.4) for those entities, MUST be specified in the IANA		(see Section 5.1.4) for those entities, MUST be specified in the IANA
	registration.		registration.
	Entity domain type identifiers prefixed with "priv:" are reserved for		Entity domain type identifiers prefixed with "priv:" are reserved for
	Private Use (see [RFC8126]) without a need to register with IANA.		Private Use (see [RFC8126]) without a need to register with IANA.
	The definition of a private use entity domain type MUST apply the		The definition of a private-use entity domain type MUST apply the
	same way in all property maps of an IRD where it is present.		same way in all property maps of an IRD where it is present.
	5.1.2. Entity Domain Name		5.1.2. Entity Domain Name
	As discussed in Section 3.2, an entity domain is characterized by a		As discussed in Section 3.2, an entity domain is characterized by a
	type and identified by a name.		type and identified by a name.
	This document distinguishes three categories of entity domains:		This document distinguishes three categories of entity domains:
	resource-specific entity domains, resource-agnostic entity domains		resource-specific entity domains, resource-agnostic entity domains,
	and self-defined entity domains. Their entity domain names are		and self-defined entity domains. Their entity domain names are
	constructed as specified in the following sub-sections.		constructed as specified in the following subsections.
	Each entity domain is identified by a unique entity domain name.		Each entity domain is identified by a unique entity domain name.
	Borrowing the symbol "::=" from the Backus-Naur Form notation		Borrowing the symbol "::=" from the Backus-Naur Form notation
	[RFC5511], the format of an entity domain name is defined as follows:		[RFC5511], the format of an entity domain name is defined as follows:
	EntityDomainName ::= [ [ ResourceID ] '.' ] EntityDomainType		EntityDomainName ::= [ [ ResourceID ] '.' ] EntityDomainType
	The presence and construction of the component		The presence and construction of the component
	"[ [ ResourceID ] '.' ]"		"[ [ ResourceID ] '.' ]"
	depends on the category of entity domain.		depends on the category of entity domain.
	Note that the '.' separator is not allowed in EntityDomainType and		Note that the '.' separator is not allowed in EntityDomainType, and
	hence there is no ambiguity on whether an entity domain name refers		hence there is no ambiguity on whether an entity domain name refers
	to a resource-agnostic entity domain or a resource-specific entity		to a resource-agnostic entity domain or a resource-specific entity
	domain.		domain.
	Note also that Section 10.1 of [RFC7285] specifies the format of the		Note also that Section 10.1 of [RFC7285] specifies the format of the
	PID name which is the format of the resource ID including the		PID name, which is the format of the resource identifier including
	following specification: "the '.' separator is reserved for future		the following specification:
	use and MUST NOT be used unless specifically indicated in this
	document, or an extension document". The present extension keeps the
	format specification of [RFC7285], hence the '.' separator MUST NOT
	be used in an information resource ID.
	5.1.2.1. Resource-specific Entity Domain		| The '.' separator is reserved for future use and MUST NOT be used
			| unless specifically indicated in this document, or an extension
			| document.
			The present extension keeps the format specification of [RFC7285],
			hence the '.' separator MUST NOT be used in an information resource
			identifier.
			5.1.2.1. Resource-Specific Entity Domain
	A resource-specific entity domain is identified by an entity domain		A resource-specific entity domain is identified by an entity domain
	name constructed as follows. It MUST start with a resource ID using		name constructed as follows. It MUST start with a resource
	the ResourceID type defined in Section 10.2 of [RFC7285], followed by		identifier using the ResourceID type defined in Section 10.2 of
	the '.' separator (U+002E), followed by a string of the type		[RFC7285], followed by the '.' separator (U+002E), followed by a
	EntityDomainType specified in Section 5.1.1.		string of the type EntityDomainType specified in Section 5.1.1.
	For example, if an ALTO server provides two network maps "netmap-1"		For example, if an ALTO server provides two network maps "netmap-1"
	and "netmap-2", these network maps can define two resource-specific		and "netmap-2", these network maps can define two resource-specific
	domains of type "pid", respectively identified by "netmap-1.pid" and		domains of type "pid", respectively identified by "netmap-1.pid" and
	"netmap-2.pid".		"netmap-2.pid".
	5.1.2.2. Resource-agnostic Entity Domain		5.1.2.2. Resource-Agnostic Entity Domain
	A resource-agnostic entity domain contains entities that are		A resource-agnostic entity domain contains entities that are
	identified independently of any information resource. The identifier		identified independently of any information resource. The identifier
	of a resource-agnostic entity domain is simply the identifier of its		of a resource-agnostic entity domain is simply the identifier of its
	entity domain type. For example, "ipv4" and "ipv6" identify the two		entity domain type. For example, "ipv4" and "ipv6" identify the two
	resource-agnostic Internet address entity domains defined in		resource-agnostic Internet address entity domains defined in
	Section 6.1.		Section 6.1.
	5.1.2.3. Self-defined Entity Domain		5.1.2.3. Self-Defined Entity Domain
	A property map can define properties on entities that are specific to		A property map can define properties for entities that are specific
	a unique information resource, which is the property map itself.		to a unique information resource, which is the property map itself.
	This may be the case when an ALTO Server provides properties on a set		This may be the case when an ALTO Server provides properties for a
	of entities that are defined only in this property map, are not		set of entities that are defined only in this property map, are not
	relevant to another one and do not depend on another specific		relevant to another one, and do not depend on another specific
	resource.		resource.
	For example: a specialised property map may define a domain of type		For example: a specialized property map may define a domain of type
	"ane", defined in [I-D.ietf-alto-path-vector], that contains a set of		"ane", defined in [PATH-VECTOR], that contains a set of ANEs
	ANEs representing data centers, that each have a persistent		representing data centers that each have a persistent identifier and
	identifier and are relevant only to this property map.		are relevant only to this property map.
	In this case, the entity domain is qualified as "self-defined". The		In this case, the entity domain is qualified as "self-defined". The
	identifier of a self-defined entity domain can be of the format:		identifier of a self-defined entity domain can be of the format:
	EntityDomainName ::= '.' EntityDomainType		EntityDomainName ::= '.' EntityDomainType
	where '.' indicates that the entity domain only exists within the		where '.' indicates that the entity domain only exists within the
	property map resource using it.		property map resource using it.
	A self-defined entity domain can be viewed as a particular case of		A self-defined entity domain can be viewed as a particular case of
	resource-specific entity domain, where the specific resource is the		resource-specific entity domain, where the specific resource is the
	current resource that uses this entity domain. In that case, for the		current resource that uses this entity domain. In that case, for the
	sake of simplification, the component "ResourceID" MUST be omitted in		sake of simplification, the component ResourceID MUST be omitted in
	its entity domain name.		its entity domain name.
	5.1.3. Entity Identifier		5.1.3. Entity Identifier
	Entities in an entity domain are identified by entity identifiers		Entities in an entity domain are identified by entity identifiers
	(EntityID) of the following format:		(EntityID) of the following format:
	EntityID ::= EntityDomainName ':' DomainTypeSpecificEntityID		EntityID ::= EntityDomainName ':' DomainTypeSpecificEntityID
	Examples from the Internet address entity domains include individual		Examples from the Internet address entity domains include individual
	IP addresses such as "net1.ipv4:192.0.2.14" and		IP addresses such as "net1.ipv4:192.0.2.14" and
	"net1.ipv6:2001:db8::12", as well as address blocks such as		"net1.ipv6:2001:db8::12", as well as address blocks such as
	"net1.ipv4:192.0.2.0/26" and "net1.ipv6:2001:db8::/48".		"net1.ipv4:192.0.2.0/26" and "net1.ipv6:2001:db8::/48".
	The format of the second part of an entity identifier,		The format of the second part of an entity identifier,
	DomainTypeSpecificEntityID, depends on the entity domain type, and		DomainTypeSpecificEntityID, depends on the entity domain type and
	MUST be specified when defining a new entity domain type and		MUST be specified when defining a new entity domain type and
	registering it with the IANA. Identifiers MAY be hierarchical, and		registering it with IANA. Identifiers MAY be hierarchical, and
	properties MAY be inherited based on that hierarchy. The rules		properties MAY be inherited based on that hierarchy. The rules
	defining any hierarchy or inheritance MUST be defined when the entity		defining any hierarchy or inheritance MUST be defined when the entity
	domain type is registered.		domain type is registered.
	The type EntityID is used in this document to denote a JSON string		The type EntityID is used in this document to denote a JSON string
	representing an entity identifier in this format.		representing an entity identifier in this format.
	Note that two entity identifiers with different valid textual		Note that two entity identifiers with different, valid textual
	representations may refer to the same entity, for a given entity		representations may refer to the same entity, for a given entity
	domain. For example, the strings "net1.ipv6:2001:db8::1" and		domain. For example, the strings "net1.ipv6:2001:db8::1" and
	"net1.ipv6:2001:db8:0:0:0:0:0:1" refer to the same entity in the		"net1.ipv6:2001:db8:0:0:0:0:0:1" refer to the same entity in the
	"ipv6" entity domain. Such equivalences should be established by the		"ipv6" entity domain. Such equivalences should be established by the
	object represented by DomainTypeSpecificEntityID, for example,		object represented by DomainTypeSpecificEntityID. For example,
	[RFC5952] establishes equivalence for IPv6 addresses, while [RFC4632]		[RFC5952] establishes equivalence for IPv6 addresses, while [RFC4632]
	does so for IPv4 addresses.		does so for IPv4 addresses.
	5.1.4. Hierarchy and Inheritance		5.1.4. Hierarchy and Inheritance
	To simplify the representation, some types of entity domains allow		To simplify the representation, some types of entity domains allow
	the ALTO Client and Server to use a hierarchical entity identifier		the ALTO Client and Server to use a hierarchical entity identifier
	format to represent a block of individual entities. For instance, in		format to represent a block of individual entities. For instance, in
	an IPv4 domain "net1.ipv4", a CIDR "net1.ipv4:192.0.2.0/26" covers 64		an IPv4 domain "net1.ipv4", a CIDR "net1.ipv4:192.0.2.0/26" covers 64
	individual IPv4 entities. In this case, the corresponding property		individual IPv4 entities. In this case, the corresponding property
	skipping to change at page 23, line 36 ¶		skipping to change at line 1060 ¶
	Each entity property has a type to indicate the encoding and the		Each entity property has a type to indicate the encoding and the
	semantics of the value of this entity property, and has a name to		semantics of the value of this entity property, and has a name to
	identify it.		identify it.
	5.2.1. Entity Property Type		5.2.1. Entity Property Type
	The type EntityPropertyType is used in this document to indicate a		The type EntityPropertyType is used in this document to indicate a
	string denoting an entity property type. The string MUST be no more		string denoting an entity property type. The string MUST be no more
	than 32 characters, and it MUST NOT contain characters other than US-		than 32 characters, and it MUST NOT contain characters other than US-
	ASCII alphanumeric characters (U+0030-U+0039, U+0041-U+005A, and		ASCII alphanumeric characters (U+0030-U+0039, U+0041-U+005A, and
	U+0061-U+007A), the hyphen ('-', U+002D), the colon (':', U+003A), or		U+0061-U+007A), the hyphen-minus ('-', U+002D), the colon (':',
	the low line ('_', U+005F). Note that the '.' separator is not		U+003A), or the low line ('_', U+005F). Note that the '.' separator
	allowed because it is reserved to separate an entity property type		is not allowed because it is reserved to separate an entity property
	and an information resource identifier when an entity property is		type and an information resource identifier when an entity property
	resource-specific.		is resource-specific.
	While, in Section 5.1.1, character ":" is allowed with restrictions		While Section 5.1.1 allows the use of the character ":" with
	on entity domain identifiers, it can be used without restrictions on		restrictions on entity domain identifiers, it can be used without
	entity property type identifiers. This relates to [RFC7285], where a		restrictions on entity property type identifiers. This relates to
	Server can define properties on endpoints "ipv4" and "ipv6". In the		[RFC7285], where a Server can define properties for endpoints "ipv4"
	present extension, there is a mapping of ALTO entity domain types		and "ipv6". In the present extension, there is a mapping of ALTO
	"ipv4" and "ipv6", to ALTO address types "ipv4" and "ipv6".		entity domain types "ipv4" and "ipv6" to ALTO address types "ipv4"
	Properties defined on "ipv4" and "ipv6" endpoints should be re-usable		and "ipv6". Properties defined for "ipv4" and "ipv6" endpoints
	on "ipv4" and "ipv6" entities. Forbidding the usage of ":" in a non-		should be reusable on "ipv4" and "ipv6" entities. Forbidding the
	private entity property type identifier would not allow to use		usage of ":" in a non-private entity property type identifier would
	properties previously defined on "ipv4" and "ipv6" endpoints because		not allow the use of properties previously defined for "ipv4" and
	their identifiers would be invalid.		"ipv6" endpoints because their identifiers would be invalid.
	Although ":" or "_::-" are valid entity domain types, it is desirable		Although ":" or "_::-" are valid entity domain types, it is desirable
	to add characters such as alphanumeric ones, for better		to add characters, such as alphanumeric ones, for better
	intelligibility.		intelligibility.
	Identifiers prefixed with "priv:" are reserved for Private Use		Identifiers prefixed with "priv:" are reserved for Private Use
	[RFC8126] without a need to register with IANA. All other		[RFC8126] without a need to register with IANA. All other
	identifiers for entity property types MUST be registered in the "ALTO		identifiers for entity property types MUST be registered in the "ALTO
	Entity Property Type Registry", defined in Section 12.4. The		Entity Property Types" registry, which is defined in Section 12.4.
	intended semantics of the entity property type MUST be specified in		The intended semantics of the entity property type MUST be specified
	the IANA registration.		in the IANA registration.
	For an entity property identifier with the "priv:" prefix, an		For an entity property identifier with the "priv:" prefix, an
	additional string (e.g., company identifier or random string) MUST		additional string (e.g., company identifier or random string) MUST
	follow the prefix to reduce potential collisions, that is, the string		follow the prefix to reduce potential collisions, that is, the string
	"priv:" alone is not a valid entity property identifier. The		"priv:" alone is not a valid entity property identifier. The
	definition of a private use entity property type must apply the same		definition of a private-use entity property type must apply the same
	way in all property maps of an IRD where it is present.		way in all property maps of an IRD where it is present.
	To distinguish from the endpoint property type, the entity property		To distinguish from the endpoint property type, the entity property
	type has the following characteristics:		type has the following characteristics:
	* Some entity property types are applicable to entities in		* Some entity property types are applicable only to entities in
	particular entity domain types only. For example, the property		particular entity domain types. For example, the property type
	type "pid" is applicable to entities in the entity domain types		"pid" is applicable to entities in the entity domain types "ipv4"
	"ipv4" or "ipv6" while is not applicable to entities in an entity		or "ipv6", while it is not applicable to entities in an entity
	domain of type "pid".		domain of type "pid".
	* The intended semantics of the value of an entity property may also		* The intended semantics of the value of an entity property may also
	depend on the entity domain type. For example, suppose that a		depend on the entity domain type. For example, suppose that a
	property named "geo-location" is defined as the coordinates of a		property named "geo-location" is defined as the coordinates of a
	point, encoded as: "latitude longitude [altitude]." When applied		point and is encoded as: "latitude longitude [altitude]." When
	to an entity that represents a specific host computer, identified		applied to an entity that represents a specific host computer and
	by an address in an entity domain of type "ipv4" or "ipv6", the		identified by an address in an entity domain of type "ipv4" or
	"geo-location" property would define the host's location.		"ipv6", the "geo-location" property would define the host's
	However, when applied to an entity in a "pid" domain type, the		location. However, when applied to an entity in a domain of type
	property would indicate a location representative of all hosts in		"pid", the property would indicate a location representative of
	this "pid" entity.		all hosts in this "pid" entity.
	5.2.2. Entity Property Name		5.2.2. Entity Property Name
	Each entity property is identified by an entity property name, which		Each entity property is identified by an entity property name, which
	is a string of the following format:		is a string of the following format:
	EntityPropertyName ::= [ [ ResourceID ] '.' ] EntityPropertyType		EntityPropertyName ::= [ [ ResourceID ] '.' ] EntityPropertyType
	Similar to the endpoint property type defined in Section 10.8 of		Similar to the endpoint property type defined in Section 10.8 of
	[RFC7285], each entity property may be defined by either the property		[RFC7285], each entity property may be defined by either the property
	map itself (self-defined) or some other specific information resource		map itself (self-defined) or some other specific information resource
	(resource-specific).		(resource-specific).
	The entity property name of a resource-specific entity property		The entity property name of a resource-specific entity property
	starts with a string of the type ResourceID defined in [RFC7285],		starts with a string of the type ResourceID defined in [RFC7285],
	followed by the '.' separator (U+002E) and a EntityDomainType typed		followed by the '.' separator (U+002E) and an EntityDomainType typed
	string. For example, the "pid" properties of an "ipv4" entity		string. For example, the "pid" properties of an "ipv4" entity
	defined by two different maps "net-map-1" and "net-map-2" are		defined by two different maps "net-map-1" and "net-map-2" are
	identified by "net-map-1.pid" and "net-map-2.pid" respectively.		identified by "net-map-1.pid" and "net-map-2.pid" respectively.
	The specific information resource of an entity property may be the		The specific information resource of an entity property may be the
	current information resource itself, that is, the property map		current information resource itself, that is, the property map
	defining the property. In that case, the ResourceID in the property		defining the property. In that case, the ResourceID in the property
	name SHOULD be omitted. For example, the property name ".asn"		name SHOULD be omitted. For example, the property name ".ASN"
	applied to an entity identified by its IPv4 address, indicates the AS		applied to an entity identified by its IPv4 address indicates the AS
	number of the AS that "owns" the entity, where the returned AS number		number of the AS that "owns" the entity, where the returned AS number
	is defined by the property map itself.		is defined by the property map itself.
	5.2.3. Format for Entity Property Value		5.2.3. Format for Entity Property Value
	Section 11.4.1.6 of [RFC7285] specifies that an implementation of the		Section 11.4.1.6 of [RFC7285] specifies that an implementation of the
	Endpoint Property Service specified in [RFC7285] SHOULD assume that		Endpoint Property Service specified in [RFC7285] SHOULD assume that
	the property value is a JSONString and fail to parse if it is not.		the property value is a JSONString and fail to parse if it is not.
	This document extends the format of a property value by allowing it		This document extends the format of a property value by allowing it
	to be a JSONValue instead of just a JSONString.		to be a JSONValue instead of just a JSONString.
	6. Entity Domain Types Defined in this Document		6. Entity Domain Types Defined in This Document
	The definition of each entity domain type MUST include (1) the entity		The definition of each entity domain type MUST include the entity
	domain type name and (2) domain-specific entity identifiers, and MAY		domain type name and the domain-specific entity identifiers. The
	include (3) hierarchy and inheritance semantics optionally. This		definition of an entity domain type MAY include hierarchy and
	document defines three initial entity domain types as follows.		inheritance semantics. This document defines three initial entity
			domain types as follows.
	6.1. Internet Address Domain Types		6.1. Internet Address Domain Types
	The document defines two entity domain types (IPv4 and IPv6) for		The document defines two entity domain types (IPv4 and IPv6) for
	Internet addresses. Both types are resource-agnostic entity domain		Internet addresses. Both types are resource-agnostic entity domain
	types and hence define corresponding resource-agnostic entity domains		types and hence define corresponding resource-agnostic entity domains
	as well. Since the two domains use the same hierarchy and		as well. Since the two domains use the same hierarchy and
	inheritance semantics, we define the semantics together, instead of		inheritance semantics, we define the semantics together, instead of
	repeating for each.		repeating for each.
	skipping to change at page 26, line 4 ¶		skipping to change at line 1169 ¶
	6.1. Internet Address Domain Types		6.1. Internet Address Domain Types
	The document defines two entity domain types (IPv4 and IPv6) for		The document defines two entity domain types (IPv4 and IPv6) for
	Internet addresses. Both types are resource-agnostic entity domain		Internet addresses. Both types are resource-agnostic entity domain
	types and hence define corresponding resource-agnostic entity domains		types and hence define corresponding resource-agnostic entity domains
	as well. Since the two domains use the same hierarchy and		as well. Since the two domains use the same hierarchy and
	inheritance semantics, we define the semantics together, instead of		inheritance semantics, we define the semantics together, instead of
	repeating for each.		repeating for each.
	6.1.1. Entity Domain Type: IPv4		6.1.1. Entity Domain Type: IPv4
	6.1.1.1. Entity Domain Type Identifier		6.1.1.1. Entity Domain Type Identifier
	The identifier for this Entity Domain Type is "ipv4".		The identifier for this entity domain type is "ipv4".
	6.1.1.2. Domain-Specific Entity Identifiers		6.1.1.2. Domain-Specific Entity Identifiers
	Individual addresses are strings as specified by the IPv4address rule		Individual addresses are strings as specified by the IPv4address rule
	in Section 3.2.2 of [RFC3986]; Hierarchical addresses are strings as		in Section 3.2.2 of [RFC3986]; hierarchical addresses are strings as
	specified by the prefix notation in Section 3.1 of [RFC4632]. To		specified by the prefix notation in Section 3.1 of [RFC4632]. An
	define properties, an individual Internet address and the		individual Internet address and the corresponding full-length prefix
	corresponding full-length prefix are considered aliases for the same		are considered aliases for the same entity on which to define
	entity on which to define properties. Thus, "ipv4:192.0.2.0" and		properties. Thus, "ipv4:192.0.2.0" and "ipv4:192.0.2.0/32" are
	"ipv4:192.0.2.0/32" are equivalent.		equivalent.
	6.1.2. Entity Domain Type: IPv6		6.1.2. Entity Domain Type: IPv6
	6.1.2.1. Entity Domain Type Identifier		6.1.2.1. Entity Domain Type Identifier
	The identifier for this Entity Domain Type is "ipv6".		The identifier for this Entity Domain Type is "ipv6".
	6.1.2.2. Domain-Specific Entity Identifiers		6.1.2.2. Domain-Specific Entity Identifiers
	Individual addresses are strings as specified by Section 4 of		Individual addresses are strings as specified by Section 4 of
	[RFC5952]; Hierarchical addresses are strings as specified by IPv6		[RFC5952]; hierarchical addresses are strings as specified by IPv6
	address prefixes notation in Section 2.3 of [RFC4291]. To define		address prefixes notation in Section 2.3 of [RFC4291]. To define
	properties, an individual Internet address and the corresponding		properties, an individual Internet address and the corresponding
	128-bit prefix are considered aliases for the same entity. That is,		128-bit prefix are considered aliases for the same entity. That is,
	"ipv6:2001:db8::1" and "ipv6:2001:db8::1/128" are equivalent, and		"ipv6:2001:db8::1" and "ipv6:2001:db8::1/128" are equivalent and have
	have the same set of properties.		the same set of properties.
	6.1.3. Hierarchy and Inheritance of Internet Address Domains		6.1.3. Hierarchy and Inheritance of Internet Address Domains
	Both Internet address domains allow property values to be inherited.		Both Internet address domains allow property values to be inherited.
	Specifically, if a property P is not defined for a specific Internet		Specifically, if a property P is not defined for a specific Internet
	address I, but P is defined for a hierarchical Internet address C		address I, but P is defined for a hierarchical Internet address C
	which represents a set of addresses containing I, then the address I		that represents a set of addresses containing I, then the address I
	inherits the value of P defined for the hierarchical address C. If		inherits the value of P defined for the hierarchical address C. If
	more than one such hierarchical addresses define a value for P, I		more than one such hierarchical addresses define a value for P, I
	inherits the value of P in the hierarchical address with the longest		inherits the value of P in the hierarchical address with the longest
	prefix. Note that this longest prefix rule ensures no multiple value		prefix. Note that this longest prefix rule ensures no multiple value
	inheritances, and hence no ambiguity.		inheritances, and hence no ambiguity.
	Hierarchical addresses can also inherit properties: if a property P		Hierarchical addresses can also inherit properties. For instance, if
	is not defined for the hierarchical address C, but is defined for a		a property P:
	set of hierarchical addresses, where each address C' in the set
	contains all IP addresses in C, and C' has a shorter prefix length		* is not defined for the hierarchical address C,
	than C, then C MUST inherit the property P from the C' having the
	longest prefix length.		* but is defined for a set of hierarchical addresses where:
			- each address C' in the set contains all IP addresses in C, and
			- C' has a shorter prefix length than C,
			then C MUST inherit the property P from the C' having the longest
			prefix length.
	As an example, suppose that a server defines a property P for the		As an example, suppose that a server defines a property P for the
	following entities:		following entities:
	ipv4:192.0.2.0/26: P=v1		+--------------------+------+
	ipv4:192.0.2.0/28: P=v2		| ipv4:192.0.2.0/26: | P=v1 |
	ipv4:192.0.2.0/30: P=v3		+--------------------+------+
	ipv4:192.0.2.0: P=v4		| ipv4:192.0.2.0/28: | P=v2 |
			+--------------------+------+
			| ipv4:192.0.2.0/30: | P=v3 |
			+--------------------+------+
			| ipv4:192.0.2.0: | P=v4 |
			+--------------------+------+
	Figure 1: Defined Property Values.		Table 1: Defined Property
			Values
	Then the following entities have the indicated values:		Then the following entities have the indicated values:
	ipv4:192.0.2.0: P=v4		+--------------------+---------------+
	ipv4:192.0.2.1: P=v3		| ipv4:192.0.2.0: | P=v4 |
	ipv4:192.0.2.16: P=v1		+--------------------+---------------+
	ipv4:192.0.2.32: P=v1		| ipv4:192.0.2.1: | P=v3 |
	ipv4:192.0.2.64: (not defined)		+--------------------+---------------+
	ipv4:192.0.2.0/32: P=v4		| ipv4:192.0.2.16: | P=v1 |
	ipv4:192.0.2.0/31: P=v3		+--------------------+---------------+
	ipv4:192.0.2.0/29: P=v2		| ipv4:192.0.2.32: | P=v1 |
	ipv4:192.0.2.0/27: P=v1		+--------------------+---------------+
	ipv4:192.0.2.0/25: (not defined)		| ipv4:192.0.2.64: | (not defined) |
			+--------------------+---------------+
			| ipv4:192.0.2.0/32: | P=v4 |
			+--------------------+---------------+
			| ipv4:192.0.2.0/31: | P=v3 |
			+--------------------+---------------+
			| ipv4:192.0.2.0/29: | P=v2 |
			+--------------------+---------------+
			| ipv4:192.0.2.0/27: | P=v1 |
			+--------------------+---------------+
			| ipv4:192.0.2.0/25: | (not defined) |
			+--------------------+---------------+
	Figure 2: Inherited Property Values.		Table 2: Inherited Property Values
	An ALTO server MAY explicitly indicate a property as not having a		An ALTO server MAY explicitly indicate a property as not having a
	value for a particular entity. That is, a server MAY say that		value for a particular entity. That is, a server MAY say that
	property P of entity X is "defined to have no value", instead of		property P of entity X is "defined to have no value" instead of
	"undefined". To indicate "no value", a server MAY perform different		"undefined". To indicate "no value", a server MAY perform different
	behaviors:		behaviors:
	* If entity X would inherit a value for property P, and if the ALTO		* If entity X would inherit a value for property P, and if the ALTO
	server decides to say that "X has no value for P", then the ALTO		server decides to say that "X has no value for P", then the ALTO
	server MUST return a "null" value for that property on X. In this		server MUST return a "null" value for that property on X. In this
	case, the ALTO client MUST recognize the JSON "null" value as "no		case, the ALTO client MUST recognize the JSON "null" value as "no
	value" and interpret it as "do not apply the inheritance rules for		value" and interpret it as "do not apply the inheritance rules for
	this property on X".		this property on X".
	* If the entity would not inherit a value, then the ALTO server MAY		* If the entity would not inherit a value, then the ALTO server MAY
	return "null" or just omit the property. In this case, the ALTO		return "null" or just omit the property. In this case, the ALTO
	client cannot infer the value for this property of this entity		client cannot infer the value for this property of this entity
	from the Inheritance rules. So, the client MUST interpret that		from the Inheritance rules. Thus, the client MUST interpret that
	this property has no value.		this property has no value.
	If the ALTO server does not define any properties for an entity, then		If the ALTO server does not define any properties for an entity, then
	the server MAY omit that entity from the response.		the server MAY omit that entity from the response.
	6.1.4. Defining Information Resource Media Type for domain types IPv4		6.1.4. Defining Information Resource Media Type for Domain Types IPv4
	and IPv6		and IPv6
	Entity domain types "ipv4" and "ipv6" both allow to define resource		Entity domain types "ipv4" and "ipv6" both allow the definition of
	specific entity domains. When resource specific domains are defined		resource-specific entity domains. When resource-specific domains are
	with entities of domain type "ipv4" or "ipv6", the defining		defined with entities of domain type "ipv4" or "ipv6", the defining
	information resource for an entity domain of type "ipv4" or "ipv6"		information resource for an entity domain of type "ipv4" or "ipv6"
	MUST be a Network Map. The media type of a defining information		MUST be a network map. The media type of a defining information
	resource is therefore:		resource is therefore:
	application/alto-networkmap+json		application/alto-networkmap+json
	6.2. Entity Domain Type: PID		6.2. Entity Domain Type: PID
	The PID entity domain associates property values with the PIDs in a		The PID entity domain associates property values with the PIDs in a
	network map. Accordingly, this entity domain always depends on a		network map. Accordingly, this entity domain always depends on a
	network map.		network map.
	6.2.1. Entity Domain Type Identifier		6.2.1. Entity Domain Type Identifier
	The identifier for this Entity Domain Type is "pid"		The identifier for this Entity Domain Type is "pid".
	6.2.2. Domain-Specific Entity Identifiers		6.2.2. Domain-Specific Entity Identifiers
	The entity identifiers are the PID names of the associated network		The entity identifiers are the PID names of the associated network
	map.		map.
	6.2.3. Hierarchy and Inheritance		6.2.3. Hierarchy and Inheritance
	There are no hierarchy or inheritance for properties associated with		There is no hierarchy or inheritance for properties associated with
	PIDs.		PIDs.
	6.2.4. Defining Information Resource Media Type for Domain Type PID		6.2.4. Defining Information Resource Media Type for Domain Type PID
	The entity domain type "pid" allows to define resource specific		The entity domain type "pid" allows the definition of resource-
	entity domains. When resource specific domains are defined with		specific entity domains. When resource-specific domains are defined
	entities of domain type "pid", the defining information resource for		with entities of domain type "pid", the defining information resource
	entity domain type "pid" MUST be a Network Map. The media type of a		for entity domain type "pid" MUST be a network map. The media type
	defining information resource is therefore:		of a defining information resource is therefore:
	application/alto-networkmap+json		application/alto-networkmap+json
	6.2.5. Relationship To Internet Addresses Domains		6.2.5. Relationship To Internet Addresses Domains
	The PID domain and the Internet address domains are completely		The PID domain and the Internet address domains are completely
	independent; the properties associated with a PID have no relation to		independent; the properties associated with a PID have no relation to
	the properties associated with the prefixes or endpoint addresses in		the properties associated with the prefixes or endpoint addresses in
	that PID. An ALTO server MAY choose to assign all the properties of		that PID. An ALTO server MAY choose to assign all the properties of
	a PID to the prefixes in that PID or only some of these properties.		a PID to the prefixes in that PID or only some of these properties.
	For example, suppose "PID1" consists of the prefix		For example, suppose "PID1" consists of the prefix
	"ipv4:192.0.2.0/24", and has the property "P" with value "v1". The		"ipv4:192.0.2.0/24" and has the property P with value v1. The
	Internet address entities "ipv4:192.0.2.0" and "ipv4:192.0.2.0/24" in		Internet address entities "ipv4:192.0.2.0" and "ipv4:192.0.2.0/24" in
	the IPv4 domain MAY have a value for the property "P", and if they		the IPv4 domain MAY have a value for the property P, and if they do,
	do, it is not necessarily "v1".		it is not necessarily v1.
	6.3. Internet Address Properties vs. PID Properties		6.3. Internet Address Properties vs. PID Properties
	Because the Internet address and PID domains relate to completely		Because the Internet address and PID domains relate to completely
	distinct domain types, the question may arise as to which entity		distinct domain types, the question may arise as to which entity
	domain type is the best for a property. In general, the Internet		domain type is the best for a property. In general, the Internet
	address domain types are RECOMMENDED for properties that are closely		address domain types are RECOMMENDED for properties that are closely
	related to the Internet address, or are associated with, and		related to the Internet address or are associated with, and inherited
	inherited through, hierarchical addresses.		through, hierarchical addresses.
	The PID domain type is RECOMMENDED for properties that arise from the		The PID domain type is RECOMMENDED for properties that arise from the
	definition of the PID, rather than from the Internet address prefixes		definition of the PID, rather than from the Internet address prefixes
	in that PID.		in that PID.
	For example, because Internet addresses are allocated to service		For example, because Internet addresses are allocated to service
	providers by blocks of prefixes, an "ISP" property would be best		providers by blocks of prefixes, an "ISP" property would be best
	associated with Internet address domain types. On the other hand, a		associated with Internet address domain types. On the other hand, a
	property that explains why a PID was formed, or how it relates to a		property that explains why a PID was formed, or how it relates to a
	provider's network, would best be associated with the PID domain		provider's network, would best be associated with the PID domain
	type.		type.
	7. Property Map		7. Property Map
	A property map returns the properties defined for all entities in one		A property map returns the properties defined for all entities in one
	or more domains, e.g., the "location" property of entities in "pid"		or more domains, e.g., the "location" property of entities in a
	domain, and the "ASN" property of entities in "ipv4" and "ipv6"		domain of type "pid", and the "ASN" property of entities in domains
	domains. Section 10.4 gives an example of a property map request and		of types "ipv4" and "ipv6". Section 10.4 gives an example of a
	its response.		property map request and its response.
	Downloading the whole property map is a way for the Client to obtain		Downloading the whole property map is a way for the Client to obtain
	the Entity IDs that can be used as input for a Filtered Property Map		the entity identifiers that can be used as input for a filtered
	request. However, a whole property map may be too voluminous for a		property map request. However, a whole property map may be too
	Client that only wants the list of applicable Entity IDs. How to		voluminous for a Client that only wants the list of applicable entity
	obtain the list of entities of a filtered property map in a		identifiers. How to obtain the list of entities of a filtered
	simplified response is specified in Section 8.		property map in a simplified response is specified in Section 8.
	7.1. Media Type		7.1. Media Type
	The media type of a property map is "application/alto-propmap+json".		The media type of a property map is "application/alto-propmap+json".
	7.2. HTTP Method		7.2. HTTP Method
	The property map is requested using the HTTP GET method.		The property map is requested using the HTTP GET method.
	7.3. Accept Input Parameters		7.3. Accept Input Parameters
	A Property Map has no Accept Input parameters.		A property map has no Accept Input parameters.
	7.4. Capabilities		7.4. Capabilities
	The capabilities are defined by an object of type		The capabilities are defined by an object of type
	PropertyMapCapabilities:		PropertyMapCapabilities:
	object {		object {
	EntityPropertyMapping mappings;		EntityPropertyMapping mappings;
	} PropertyMapCapabilities;		} PropertyMapCapabilities;
	skipping to change at page 30, line 40 ¶		skipping to change at line 1416 ¶
	with fields:		with fields:
	mappings: A JSON object whose keys are names of entity domains and		mappings: A JSON object whose keys are names of entity domains and
	values are the supported entity properties of the corresponding		values are the supported entity properties of the corresponding
	entity domains.		entity domains.
	7.5. Uses		7.5. Uses
	The "uses" field of a property map resource in an IRD entry specifies		The "uses" field of a property map resource in an IRD entry specifies
	the resources in this same IRD on which this property map directly		the resources in this same IRD on which this property map directly
	depends. It is an array of resource ID(s). This array identifies		depends. It is an array of resource identifier(s). This array
	the defining information resources associated with the resource-		identifies the defining information resources associated with the
	specific entity domains and properties that are indicated in this		resource-specific entity domains and properties that are indicated in
	resource.		this resource.
	7.6. Response		7.6. Response
	If the entity domains in this property map depend on other resources,		If the entity domains in this property map depend on other resources,
	the "dependent-vtags" field in the "meta" field of the response MUST		the "dependent-vtags" field in the "meta" field of the response MUST
	be an array that includes the version tags of those resources, and		be an array that includes the version tags of those resources, and
	the order MUST be consistent with the "uses" field of this property		the order MUST be consistent with the "uses" field of this property
	map resource. The data component of a property map response is named		map resource. The data component of a property map response is named
	"property-map", which is a JSON object of type PropertyMapData,		"property-map", which is a JSON object of type PropertyMapData,
	where:		where:
	skipping to change at page 31, line 34 ¶		skipping to change at line 1459 ¶
	strings of type PropertyName. A protocol implementation SHOULD		strings of type PropertyName. A protocol implementation SHOULD
	assume that the property value is either a JSONString or a JSON		assume that the property value is either a JSONString or a JSON
	"null" value, and fail to parse if it is not, unless the		"null" value, and fail to parse if it is not, unless the
	implementation is using an extension to this document that indicates		implementation is using an extension to this document that indicates
	when and how property values of other data types are signaled.		when and how property values of other data types are signaled.
	For each entity in the property map:		For each entity in the property map:
	* If the entity is in a resource-specific entity domain, the ALTO		* If the entity is in a resource-specific entity domain, the ALTO
	server MUST only return self-defined properties and resource-		server MUST only return self-defined properties and resource-
	specific properties which depend on the same resource as the		specific properties that depend on the same resource as the entity
	entity does. The ALTO client MUST ignore any resource-specific		does. The ALTO client MUST ignore any resource-specific property
	property for this entity if the mapping between this resource-		for this entity if the mapping between this resource-specific
	specific property and this entity is not indicated, in the IRD, in		property and this entity is not indicated, in the IRD, in the
	the "mappings" capability of the property map resource.		"mappings" capability of the property map resource.
	* If the entity identifier is resource-agnostic, the ALTO server		* If the entity identifier is resource-agnostic, the ALTO server
	SHOULD return the self-defined properties and all the resource-		SHOULD return the self-defined properties and all the resource-
	specific properties that are defined in the property defining		specific properties defined in the property-defining information
	information resources indicated, in the IRD, in the "mappings"		resources that are indicated, in the IRD, in the "mappings"
	capability of the property map resource, unless property values		capability of the property map resource, unless property values
	can be omitted upon some inheritance rules.		can be omitted upon some inheritance rules.
	The ALTO server MAY omit property values that are inherited rather		The ALTO server MAY omit property values that are inherited rather
	than explicitly defined, in order to achieve more compact encoding.		than explicitly defined in order to achieve more compact encoding.
	As a consequence, the ALTO Client MUST NOT assume inherited property		As a consequence, the ALTO Client MUST NOT assume inherited property
	values will all be present. If the Client needs inherited values, it		values will all be present. If the Client needs inherited values, it
	MUST use the entity domain's inheritance rules to deduce those		MUST use the entity domain's inheritance rules to deduce those
	values.		values.
	8. Filtered Property Map		8. Filtered Property Map
	A filtered property map returns the values of a set of properties for		A filtered property map returns the values of a set of properties for
	a set of entities selected by the client.		a set of entities selected by the client.
	Section 10.5, Section 10.6, Section 10.7 and Section 10.8 give		Sections 10.5, 10.6, 10.7, and 10.8 give examples of filtered
	examples of filtered property map requests and responses.		property map requests and responses.
	While the IRD lists all the names of the supported properties, it		While the IRD lists all the names of the supported properties, it
	only lists the names of the supported entity domains and not the		only lists the names of the supported entity domains and not the
	entity IDs. A client, sometimes, may only want to know what entity		entity identifiers. Sometimes a client only wants to know what
	IDs it can provide as input to a filtered property map request but		entity identifiers it can provide as input to a filtered property map
	wants to avoid the burden of downloading the full property map. Or		request but does not want to download the full property map, or it
	it may want to check whether some given entity IDs are eligible for a		may want to check whether some given entity identifiers are eligible
	query. To support such a case, the filtered property map supports a		for a query. To support these cases, the filtered property map
	light weight response, with empty property values.		supports a lightweight response with empty property values.
	8.1. Media Type		8.1. Media Type
	The media type of a property map resource is "application/alto-		The media type of a property map resource is "application/alto-
	propmap+json".		propmap+json".
	8.2. HTTP Method		8.2. HTTP Method
	The filtered property map is requested using the HTTP POST method.		The filtered property map is requested using the HTTP POST method.
	8.3. Accept Input Parameters		8.3. Accept Input Parameters
	The input parameters for a filtered property map request are supplied		The input parameters for a filtered property map request are supplied
	in the entity body of the POST request. This document specifies the		in the entity body of the POST request. This document specifies the
	input parameters with a data format indicated by the media type		input parameters with a data format indicated by the media type
	"application/alto-propmapparams+json", which is a JSON object of type		"application/alto-propmapparams+json", which is a JSON object of type
	ReqFilteredPropertyMap. ReqFilteredPropertyMap is designed to		ReqFilteredPropertyMap. ReqFilteredPropertyMap is designed to
	support the following cases of client requests:		support the following cases of client requests:
	* The client wants the value of a selected set of properties on a		* The client wants the value of a selected set of properties for a
	selected set of entities,		selected set of entities;
	* The client wants all properties values on all the entities,		* The client wants all property values on all the entities;
	* The client wants all entities on which a property is defined but
	is not interested in their property values,
	* The Client wants to cross-check whether some entity IDs are		* The client wants all entities for which a property is defined but
	present in the Filtered Property Map but is not interested in		is not interested in their property values; or
			* The client wants to cross-check whether some entity identifiers
			are present in the filtered property map but is not interested in
	their property values.		their property values.
	The third case is equivalent to querying the whole unfiltered		The third case is equivalent to querying the whole unfiltered
	property map, which can also be achieved with a GET request. Some		property map, which can also be achieved with a GET request. Some
	Clients however, may prefer to systematically make filtered property		Clients, however, may prefer to systematically make filtered property
	map queries, where filtering parameters may sometimes be empty.		map queries, where filtering parameters may sometimes be empty.
	The JSON object ReqFilteredPropertyMap is specified as follows:		The JSON object ReqFilteredPropertyMap is specified as follows:
	object {		object {
	EntityID entities<0..*>;		EntityID entities<0..*>;
	[EntityPropertyName properties<0..*>;]		[EntityPropertyName properties<0..*>;]
	} ReqFilteredPropertyMap;		} ReqFilteredPropertyMap;
	with fields:		with fields:
	entities: List of entity identifiers for which the specified		entities: A list of entity identifiers for which the specified
	properties are to be returned. If the list is empty, the ALTO		properties are to be returned. If the list is empty, the ALTO
	Server MUST interpret the list as if it contained a list of all		Server MUST interpret the list as if it contained a list of all
	entities currently defined in the filtered property map. The		entities currently defined in the filtered property map. The
	domain of each entity MUST be included in the list of entity		domain of each entity MUST be included in the list of entity
	domains in this resource's "capabilities" field (see Section 8.4).		domains in this resource's "capabilities" field (see Section 8.4).
	The ALTO server MUST interpret entries appearing multiple times as		The ALTO server MUST interpret entries appearing multiple times as
	if they appeared only once.		if they appeared only once.
	properties: List of properties to be returned for each entity. If		properties: A list of properties to be returned for each entity. If
	the list is empty, the ALTO Sever MUST interpret the list as if it		the list is empty, the ALTO Sever MUST interpret the list as if it
	contained a list of all properties currently defined in the		contained a list of all properties currently defined in the
	filtered property map. Each specified property MUST be included		filtered property map. Each specified property MUST be included
	in the list of properties in this resource's "capabilities" field		in the list of properties in this resource's "capabilities" field
	(see Section 8.4). The ALTO server MUST interpret entries		(see Section 8.4). The ALTO server MUST interpret entries
	appearing multiple times as if they appeared only once. This		appearing multiple times as if they appeared only once. This
	field is optional. If it is absent, the Server returns a property		field is optional. If it is absent, the Server returns a property
	value equal to the literal string "{}" for all the entity IDs of		value equal to the literal string "{}" for all the entity
	the "entities" field on which at least one property is defined.		identifiers of the "entities" field for which at least one
			property is defined.
	Note that the field "properties" is optional. When in addition, the		Note that the field "properties" is optional. In addition, when the
	"entities" field is an empty list, it corresponds to a query for all		"entities" field is an empty list, it corresponds to a query for all
	applicable entity IDs of the filtered property map, with no current		applicable entity identifiers of the filtered property map, with no
	interest on any particular property. When the "entities" field is		current interest on any particular property. When the "entities"
	not empty, it allows the Client to check whether the listed entity		field is not empty, it allows the Client to check whether the listed
	IDs can be used as input to a filtered property map query.		entity identifiers can be used as input to a filtered property map
			query.
	8.4. Capabilities		8.4. Capabilities
	The capabilities are defined by an object of type		The capabilities are defined by an object of type
	PropertyMapCapabilities, as defined in Section 7.4.		PropertyMapCapabilities, as defined in Section 7.4.
	8.5. Uses		8.5. Uses
	Same to the "uses" field of the Property Map resource (see		This is the same as the "uses" field of the property map resource
	Section 7.5).		(see Section 7.5).
	8.6. Filtered Property Map Response		8.6. Filtered Property Map Response
	The response MUST indicate an error, using ALTO protocol error		The response MUST indicate an error, using ALTO Protocol error
	handling, as defined in Section 8.5 of [RFC7285], if the request is		handling, as defined in Section 8.5 of [RFC7285], if the request is
	invalid.		invalid.
	Specifically, a filtered property map request can be invalid in the		Specifically, a filtered property map request can be invalid in the
	following cases:		following cases:
	* The input field "entities" is absent from the Client request. In		* The input field "entities" is absent from the Client request. In
	this case, the Server MUST return an "E_MISSING_FIELD" error as		this case, the Server MUST return an "E_MISSING_FIELD" error as
	defined in Section 8.5.2 of [RFC7285].		defined in Section 8.5.2 of [RFC7285].
	* An entity identifier in the "entities" field of the request is		* An entity identifier in the "entities" field of the request is
	invalid. This occurs when:		invalid. This occurs when:
	- The domain of this entity is not defined in the "entity-		- The domain of this entity is not defined in the "mappings"
	domains" capability of this resource in the IRD,		capability of this resource in the IRD, or
	- The entity identifier is not valid for the entity domain.		- The entity identifier is not valid for the entity domain.
	A valid entity identifier does never generate an error, even if		A valid entity identifier never generates an error, even if the
	the filtered property map resource does not define any properties		filtered property map resource does not define any properties for
	for it.		it.
	If an entity identifier in the "entities" field of the request is		If an entity identifier in the "entities" field of the request is
	invalid, the ALTO server MUST return an "E_INVALID_FIELD_VALUE"		invalid, the ALTO server MUST return an "E_INVALID_FIELD_VALUE"
	error defined in Section 8.5.2 of [RFC7285], and the "value" field		error defined in Section 8.5.2 of [RFC7285], and the "value" field
	of the error message SHOULD indicate the provided invalid entity		of the error message SHOULD indicate the provided invalid entity
	identifier.		identifier.
	* A property name in the "properties" field of the request is		* A property name in the "properties" field of the request is
	invalid. This occurs when this property name is not defined in		invalid. This occurs when this property name is not defined in
	the "properties" capability of this resource in the IRD.		the "properties" capability of this resource in the IRD.
	When a filtered property map resource does not define a value for		When a filtered property map resource does not define a value for
	a property requested on a particular entity, it is not an error.		a property requested for a particular entity, it is not an error.
	In this case, the ALTO server MUST omit that property from the		In this case, the ALTO server MUST omit that property from the
	response for that endpoint.		response for that endpoint.
	If a property name in "properties" in the request is invalid, the		If a property name in the "properties" field in the request is
	ALTO server MUST return an "E_INVALID_FIELD_VALUE" error defined		invalid, the ALTO server MUST return an "E_INVALID_FIELD_VALUE"
	in Section 8.5.2 of [RFC7285]. The "value" field of the error		error defined in Section 8.5.2 of [RFC7285]. The "value" field of
	message SHOULD indicate the property name.		the error message SHOULD indicate the property name.
	Some identifiers can be interpreted as both an entity name and a		Some identifiers can be interpreted as both an entity name and a
	property name, as it is the case for "pid" if it would be erroneously		property name, as is the case for "pid" if it were erroneously used
	used alone. In such a case, the Server SHOULD follow Section 8.5.2		alone. In such a case, the Server SHOULD follow Section 8.5.2 of
	of [RFC7285], that says: "For an E_INVALID_FIELD_VALUE error, the		[RFC7285], which says:
	server may include an optional field named "field" in the "meta"
	field of the response, to indicate the field that contains the wrong
	value."
	The response to a valid request is the same as for the Property Map		| For an E_INVALID_FIELD_VALUE error, the server may include an
	(see Section 7.6), except that:		| optional field named "field" in the "meta" field of the response,
			| to indicate the field that contains the wrong value.
			The response to a valid request is the same as for the property map
			(see Section 7.6) except that:
	* If the requested entities include entities with a resource-		* If the requested entities include entities with a resource-
	agnostic identifier, the "dependent-vtags" field in its "meta"		agnostic identifier, the "dependent-vtags" field in its "meta"
	field MUST include version tags of all dependent resources		field MUST include version tags of all dependent resources
	appearing in the "uses" field.		appearing in the "uses" field.
	* If the requested entities only include entities in resource-		* If the requested entities only include entities in resource-
	specific entity domains, the "dependent-vtags" field in its "meta"		specific entity domains, the "dependent-vtags" field in its "meta"
	field MUST include the version tags of the resources on which the		field MUST include the version tags of the resources on which the
	requested resource-specific entity domains and the requested		requested resource-specific entity domains and the requested
	resource-specific properties are dependent on.		resource-specific properties are dependent.
	* The response only includes the entities and properties requested		* The response only includes the entities and properties requested
	by the client. If an entity in the request is identified by a		by the client. If an entity in the request is identified by a
	hierarchical identifier (e.g., a "ipv4" or "ipv6" prefix), the		hierarchical identifier (e.g., a "ipv4" or "ipv6" prefix), the
	response MUST return all properties that are present on any		response MUST return all properties that are present for any
	address covered by the prefix, even though some of those		address covered by the prefix, even though some of those
	properties may not be present on all addresses covered by the		properties may not be present for all addresses covered by the
	prefix.		prefix.
	* When the input member "properties" is absent from the client		* When the input member "properties" is absent from the client
	request, the Server returns a property map containing all the		request, the Server returns a property map containing all the
	requested entity identifiers on which one or more properties are		requested entity identifiers for which one or more properties are
	defined. For all the entities of the returned map, the returned		defined. For all the entities of the returned map, the returned
	property value is equal to '{}'.		property value is equal to "{}".
	The filtered property map response MUST include all the inherited		The filtered property map response MUST include all the inherited
	property values for the requested entities and all the entities which		property values for the requested entities and all the entities that
	are able to inherit property values from the requested entities. To		are able to inherit property values from the requested entities. To
	achieve this goal, the ALTO server MAY follow two rules:		achieve this goal, the ALTO server MAY follow two rules:
	* If a property for a requested entity is inherited from another		* If a property for a requested entity is inherited from another
	entity not included in the request, the response MUST include this		entity not included in the request, the response MUST include this
	property for the requested entity. For example, A full property		property for the requested entity. For example, a full property
	map may skip a property P for an entity A (e.g.,		map may skip a property P for an entity A (e.g.,
	ipv4:192.0.2.0/31) if P can be derived using inheritance from		"ipv4:192.0.2.0/31") if P can be derived using inheritance from
	another entity B (e.g., ipv4:192.0.2.0/30). A filtered property		another entity B (e.g., "ipv4:192.0.2.0/30"). A filtered property
	map request may include only A but not B. In such a case, the		map request may include only A but not B. In such a case, the
	property P MUST be included in the response for A.		property P MUST be included in the response for A.
	* If there are entities covered by a requested entity but having		* If there are entities covered by a requested entity but they have
	different values for the requested properties, the response MUST		different values for the requested properties, the response MUST
	include all those entities and the different property values for		include all those entities and the different property values for
	them. For example, considering a request for property P of entity		them. For example, consider a request for property P of entity A
	A (e.g., ipv4:192.0.2.0/31), if P has value v1 for		(e.g., "ipv4:192.0.2.0/31"): if P has value v1 for
	A1=ipv4:192.0.2.0/32 and v2 for A2=ipv4:192.0.2.1/32, then, the		"A1=ipv4:192.0.2.0/32" and v2 for "A2=ipv4:192.0.2.1/32", then the
	response SHOULD include A1 and A2.		response SHOULD include A1 and A2.
	For the sake of response compactness, the ALTO server SHOULD obey the		For the sake of response compactness, the ALTO server SHOULD obey the
	following rule:		following rule:
	* If an entity identifier in the response is already covered by		* If an entity identifier in the response is already covered by
	other entities identifiers in the same response, it SHOULD be		other entities identifiers in the same response, it SHOULD be
	removed from the response. In the previous example, the entity A		removed from the response. In the previous example, the entity
	= ipv4:192.0.2.0/31 SHOULD be removed because A1 and A2 cover all		"A=ipv4:192.0.2.0/31" SHOULD be removed because A1 and A2 cover
	the addresses in A.		all the addresses in A.
	An ALTO client should be aware that the entities in the response may		An ALTO client should be aware that the entities in the response may
	be different from the entities in its request.		be different from the entities in its request.
	8.7. Entity Property Type Defined in This Document		8.7. Entity Property Type Defined in This Document
	This document defines the entity property type "pid". This property		This document defines the entity property type "pid". This property
	type extends the ALTO Endpoint Property Type "pid" defined in section		type extends the ALTO endpoint property type "pid" defined in
	7.1.1 of [RFC7285] as follows: the property has the same semantics		Section 7.1.1 of [RFC7285] as follows: the property has the same
	and applies to IPv4 and IPv6 addresses; the difference is that the		semantics and applies to IPv4 and IPv6 addresses; the difference is
	IPv4 and IPv6 addresses have evolved from the status of endpoints to		that the IPv4 and IPv6 addresses have evolved from the status of
	the status of entities.		endpoints to the status of entities.
	The defining information resource for property type MUST be a network		The defining information resource for property type MUST be a network
	map. This document requests a IANA registration for this property		map.
	8.7.1. Entity Property Type: pid		8.7.1. Entity Property Type: pid
	1. Identifier: pid
	2. Semantics: the intended semantics are the same as in [RFC7285]		Identifier: pid
	for the ALTO Endpoint Property Type "pid"
	3. Media type of defining information resource: application/alto-		Semantics: the intended semantics are the same as in [RFC7285] for
	networkmap+json		the ALTO endpoint property type "pid".
	4. Security considerations: for entity property type "pid" are the		Media type of defining information resource: application/alto-
	same as documented in [RFC7285] for the ALTO Endpoint Property		networkmap+json
	Type "pid".
			Security considerations: for entity property type "pid" are the same
			as documented in [RFC7285] for the ALTO endpoint property type
			"pid".
	9. Impact on Legacy ALTO Servers and ALTO Clients		9. Impact on Legacy ALTO Servers and ALTO Clients
	9.1. Impact on Endpoint Property Service		9.1. Impact on Endpoint Property Service
	Since the Property Map and the Filtered Property Map defined in this		Since the property map and the filtered property map defined in this
	document provide a functionality that covers the EPS defined in		document provide a functionality that covers the EPS defined in
	Section 11.4 of [RFC7285], ALTO servers may prefer to provide		Section 11.4 of [RFC7285], ALTO servers may prefer to provide
	Property Map and Filtered Property Map in place of EPS. However, for		property map and filtered property map in place of EPS. However, for
	the legacy endpoint properties, it is recommended that ALTO servers		the legacy endpoint properties, it is recommended that ALTO servers
	also provide EPS so that legacy clients can still be supported.		also provide EPS so that legacy clients can still be supported.
	9.2. Impact on Resource-Specific Properties		9.2. Impact on Resource-Specific Properties
	Section 10.8 of [RFC7285] defines two categories of endpoint		Section 10.8 of [RFC7285] defines two categories of endpoint
	properties: "resource-specific" and "global". Resource-specific		properties: "resource-specific" and "global". Resource-specific
	property names are prefixed with the ID of the resource they depend		property names are prefixed with the identifier of the resource they
	on, while global property names have no such prefix. The property		depend on, while global property names have no such prefix. The
	map and the filtered property map defined in this document define		property map and the filtered property map specified in this document
	similar categories of entity properties. The difference is that		define similar categories of entity properties. The difference is
	entity property maps do not define "global" entity properties.		that entity property maps do not define "global" entity properties.
	Instead, they define "self-defined" entity properties as a special		Instead, they define self-defined entity properties as a special case
	case of "resource-specific" entity properties, where the specific		of "resource-specific" entity properties, where the specific resource
	resource is the property map itself. This means that "self-defined"		is the property map itself. This means that self-defined properties
	properties are defined within the scope of the property map.		are defined within the scope of the property map.
	9.3. Impact on Other Properties		9.3. Impact on Other Properties
	In the present extension, properties can be defined on sets of entity		In the present extension, properties can be defined for sets of
	addresses, rather than just individual endpoint addresses as		entity addresses, rather than just individual endpoint addresses as
	initially defined in [RFC7285]. This might change the semantics of a		initially defined in [RFC7285]. This might change the semantics of a
	property. These sets can be for example hierarchical IP address		property. These sets can be, for example, hierarchical IP address
	blocks. For instance, a property such as fictitious "geo-location",		blocks. For instance, a property such as the fictitious "geo-
	defined on a set of IP addresses would have a value corresponding to		location" defined for a set of IP addresses would have a value
	a location representative of all the addresses in this set.		corresponding to a location representative of all the addresses in
			this set.
	10. Examples		10. Examples
	In this document, the HTTP message bodies of all the examples use		In this document, the HTTP message bodies of all the examples use
	Unix-style line-ending character (%x0A) as the line separator.		Unix-style line-ending character (%x0A) as the line separator.
	10.1. Network Map		10.1. Network Map
	The examples in this section use a very simple default network map:		The examples in this section use a very simple default network map:
	defaultpid: ipv4:0.0.0.0/0 ipv6:::/0		+-------------+--------------------------+
	pid1: ipv4:192.0.2.0/25		| defaultpid: | ipv4:0.0.0.0/0 ipv6:::/0 |
	pid2: ipv4:192.0.2.0/27		+-------------+--------------------------+
	pid3: ipv4:192.0.3.0/28		| pid1: | ipv4:192.0.2.0/25 |
	pid4: ipv4:192.0.3.16/28		+-------------+--------------------------+
			| pid2: | ipv4:192.0.2.0/27 |
			+-------------+--------------------------+
			| pid3: | ipv4:192.0.3.0/28 |
			+-------------+--------------------------+
			| pid4: | ipv4:192.0.3.16/28 |
			+-------------+--------------------------+
	Figure 3: Example Default Network Map		Table 3: Example Default Network Map
	And another simple alternative network map:		And another simple alternative network map:
	defaultpid: ipv4:0.0.0.0/0 ipv6:::/0		+-------------+--------------------------+
	pid1: ipv4:192.0.2.0/27		| defaultpid: | ipv4:0.0.0.0/0 ipv6:::/0 |
	pid2: ipv4:192.0.3.0/27		+-------------+--------------------------+
			| pid1: | ipv4:192.0.2.0/27 |
			+-------------+--------------------------+
			| pid2: | ipv4:192.0.3.0/27 |
			+-------------+--------------------------+
	Figure 4: Example Alternative Network Map		Table 4: Example Alternative Network Map
	10.2. Property Definitions		10.2. Property Definitions
	Beyond "pid", the examples in this section use four additional		Beyond "pid", the examples in this section use four additional,
	fictitious property types for entities of domain type "ipv4":		fictitious property types for entities of domain type "ipv4":
	"countrycode", "ASN", "ISP", and "state". These properties are		"countrycode", "ASN", "ISP", and "state". These properties are
	assumed to be resource-agnostic so their name is identical to their		assumed to be resource-agnostic so their name is identical to their
	type. The entities have the following values:		type. The entities have the following values:
	ISP ASN countrycode state		+=====================+=========+=======+=============+=======+
	ipv4:192.0.2.0/23: BitsRus - us -		| | ISP | ASN | countrycode | state |
	ipv4:192.0.2.0/28: - 65543 - NJ		+=====================+=========+=======+=============+=======+
	ipv4:192.0.2.16/28: - 65543 - CT		| ipv4:192.0.2.0/23: | BitsRus | - | us | - |
	ipv4:192.0.2.1: - - - PA		+---------------------+---------+-------+-------------+-------+
	ipv4:192.0.3.0/28: - 65544 - TX		| ipv4:192.0.2.0/28: | - | 65543 | - | NJ |
	ipv4:192.0.3.16/28: - 65544 - MN		+---------------------+---------+-------+-------------+-------+
			| ipv4:192.0.2.16/28: | - | 65543 | - | CT |
			+---------------------+---------+-------+-------------+-------+
			| ipv4:192.0.2.1: | - | - | - | PA |
			+---------------------+---------+-------+-------------+-------+
			| ipv4:192.0.3.0/28: | - | 65544 | - | TX |
			+---------------------+---------+-------+-------------+-------+
			| ipv4:192.0.3.16/28: | - | 65544 | - | MN |
			+---------------------+---------+-------+-------------+-------+
	Figure 5: Example Property Values for Internet Address Domains		Table 5: Example Property Values for Internet Address Domains
	And the examples in this section use the property "region" for the		The examples in this section use the property "region" for the PID
	PID domain of the default network map with the following values:		domain of the default network map with the following values:
	region		+=================+==========+
	pid:defaultpid: -		| | region |
	pid:pid1: us-west		+=================+==========+
	pid:pid2: us-east		| pid:defaultpid: | - |
	pid:pid3: us-south		+-----------------+----------+
	pid:pid4: us-north		| pid:pid1: | us-west |
			+-----------------+----------+
			| pid:pid2: | us-east |
			+-----------------+----------+
			| pid:pid3: | us-south |
			+-----------------+----------+
			| pid:pid4: | us-north |
			+-----------------+----------+
	Figure 6: Example Property Values for Default Network Map's PID		Table 6: Example Property
	Domain		Values for Default Network
			Map's PID Domain
	Note that "-" means the value of the property for the entity is		Note that "-" means the value of the property for the entity is
	"undefined". So the entity would inherit a value for this property		"undefined". So the entity would inherit a value for this property
	by the inheritance rule if possible. For example, the value of the		by the inheritance rule if possible. For example, the value of the
	"ISP" property for "ipv4:192.0.2.1" is "BitsRus" because of		"ISP" property for "ipv4:192.0.2.1" is "BitsRus" because of
	"ipv4:192.0.2.0/24". But the "region" property for "pid:defaultpid"		"ipv4:192.0.2.0/24". But the "region" property for "pid:defaultpid"
	has no value because no entity from which it can inherit.		has no value because there is no entity from which it can inherit.
	Similar to the PID domain of the default network map, the examples in		Similar to the PID domain of the default network map, the examples in
	this section use the property "ASN" for the PID domain of the		this section use the property "ASN" for the PID domain of the
	alternative network map with the following values:		alternative network map with the following values:
	ASN		+=================+=======+
	pid:defaultpid: -		| | ASN |
	pid:pid1: 65543		+=================+=======+
	pid:pid2: 65544		| pid:defaultpid: | - |
			+-----------------+-------+
			| pid:pid1: | 65543 |
			+-----------------+-------+
			| pid:pid2: | 65544 |
			+-----------------+-------+
	Figure 7: Example Property Values for Alternative Network Map's		Table 7: Example
	PID Domain		Property Values for
			Alternative Network
			Map's PID Domain
	10.3. Information Resource Directory (IRD)		10.3. Information Resource Directory (IRD)
	The following IRD defines ALTO Server information resources that are		The following IRD defines ALTO Server information resources that are
	relevant to the Entity Property Service. It provides a property map		relevant to the Entity Property Service. It provides a property map
	for the "ISP" and "ASN" properties. The server could have provided a		for the "ISP" and "ASN" properties. The server could have provided a
	single property map for all four properties, but does not, presumably		single property map for all four properties, but it does not,
	because the organization that runs the ALTO server believes that a		presumably because the organization that runs the ALTO server
	client is not necessarily interested in getting all four properties.		believes that a client is not necessarily interested in getting all
			four properties.
	The server provides several filtered property maps. The first		The server provides several filtered property maps. The first
	returns all four properties, and the second returns only the "pid"		returns all four properties, and the second returns only the "pid"
	property for the default network map and the "alt-network-map".		property for the default network map and the "alt-network-map".
	The filtered property maps for the "ISP", "ASN", "countrycode" and		The filtered property maps for the "ISP", "ASN", "countrycode", and
	"state" properties do not depend on the default network map (it does		"state" properties do not depend on the default network map (it does
	not have a "uses" capability), because the definitions of those		not have a "uses" capability) because the definitions of those
	properties do not depend on the default network map. The Filtered		properties do not depend on the default network map. The filtered
	Property Map providing the "pid" property does have a "uses"		property map providing the "pid" property does have a "uses"
	capability for the default network map because the default network		capability for the default network map because the default network
	map defines the values of the "pid" property.		map defines the values of the "pid" property.
	Note that for legacy clients, the ALTO server provides an Endpoint		Note that for legacy clients, the ALTO server provides an Endpoint
	Property Service for the "pid" property defined on the endpoints of		Property Service for the "pid" property defined for the endpoints of
	the default network map and the "alt-network-map".		the default network map and the "alt-network-map".
	The server provides another filtered Property map resource, named		The server provides another filtered Property map resource, named
	"ane-dc-property-map", that returns fictitious properties named		"ane-dc-property-map", that returns fictitious properties named
	"storage-capacity", "ram" and "cpu" for ANEs that have a persistent		"storage-capacity", "ram", and "cpu" for ANEs that have a persistent
	identifier. The entity domain to which the ANEs belong is "self-		identifier. The entity domain to which the ANEs belong is self-
	defined" and valid only within the property map.		defined and valid only within the property map.
	The other property maps in the returned IRD are here for purposes of		The other property maps in the returned IRD are shown here for
	illustration.		purposes of illustration.
	GET /directory HTTP/1.1		GET /directory HTTP/1.1
	Host: alto.example.com		Host: alto.example.com
	Accept: application/alto-directory+json,application/alto-error+json		Accept: application/alto-directory+json,application/alto-error+json
	HTTP/1.1 200 OK		HTTP/1.1 200 OK
	Content-Length: 2713		Content-Length: 2713
	Content-Type: application/alto-directory+json		Content-Type: application/alto-directory+json
	{		{
	skipping to change at page 42, line 4 ¶		skipping to change at line 1975 ¶
	}		}
	}		}
	},		},
	"legacy-endpoint-property" : {		"legacy-endpoint-property" : {
	"uri" : "http://alto.example.com/legacy/eps-pid",		"uri" : "http://alto.example.com/legacy/eps-pid",
	"media-type" : "application/alto-endpointprop+json",		"media-type" : "application/alto-endpointprop+json",
	"accepts" : "application/alto-endpointpropparams+json",		"accepts" : "application/alto-endpointpropparams+json",
	"capabilities" : {		"capabilities" : {
	"properties" : [ "default-network-map.pid",		"properties" : [ "default-network-map.pid",
	"alt-network-map.pid" ]		"alt-network-map.pid" ]
	}		}
	},		},
	"ane-dc-property-map": {		"ane-dc-property-map": {
	"uri" : "http://alto.example.com/propmap/lookup/ane-dc",		"uri" : "http://alto.example.com/propmap/lookup/ane-dc",
	"media-type" : "application/alto-propmap+json",		"media-type" : "application/alto-propmap+json",
	"accepts": "application/alto-propmapparams+json",		"accepts": "application/alto-propmapparams+json",
	"capabilities": {		"capabilities": {
	"mappings": {		"mappings": {
	".ane" : [ "storage-capacity", "ram", "cpu" ]		".ane" : [ "storage-capacity", "ram", "cpu" ]
	}		}
	}		}
	}		}
	}		}
	}		}
	Figure 8: Example IRD		Figure 1: Example IRD
	10.4. Full Property Map Example		10.4. Full Property Map Example
	The following example uses the properties and IRD defined in		The following example uses the properties and IRD defined in
	Section 10.3 to retrieve a Property Map for entities with the "ISP"		Section 10.3 to retrieve a property map for entities with the "ISP"
	and "ASN" properties.		and "ASN" properties.
	Note that, to be compact, the response does not include the entity		Note that, to be compact, the response does not include the entity
	"ipv4:192.0.2.1" because values of all those properties for this		"ipv4:192.0.2.1" because values of all those properties for this
	entity are inherited from other entities.		entity are inherited from other entities.
	Also note that the entities "ipv4:192.0.2.0/28" and		Also note that the entities "ipv4:192.0.2.0/28" and
	"ipv4:192.0.2.16/28" are merged into "ipv4:192.0.2.0/27", because		"ipv4:192.0.2.16/28" are merged into "ipv4:192.0.2.0/27" because they
	they have the same value of the "ASN" property. The same rule		have the same value of the "ASN" property. The same rule applies to
	applies to the entities "ipv4:192.0.3.0/28" and "ipv4:192.0.3.16/28".		the entities "ipv4:192.0.3.0/28" and "ipv4:192.0.3.16/28". Both
	Both of "ipv4:192.0.2.0/27" and "ipv4:192.0.3.0/27" omit the value		"ipv4:192.0.2.0/27" and "ipv4:192.0.3.0/27" omit the value for the
	for the "ISP" property, because it is inherited from		"ISP" property because it is inherited from "ipv4:192.0.2.0/23".
	"ipv4:192.0.2.0/23".
	GET /propmap/full/inet-ia HTTP/1.1		GET /propmap/full/inet-ia HTTP/1.1
	Host: alto.example.com		Host: alto.example.com
	Accept: application/alto-propmap+json,application/alto-error+json		Accept: application/alto-propmap+json,application/alto-error+json
	HTTP/1.1 200 OK		HTTP/1.1 200 OK
	Content-Length: 418		Content-Length: 418
	Content-Type: application/alto-propmap+json		Content-Type: application/alto-propmap+json
	{		{
	"meta": {		"meta": {
	"dependent-vtags": [		"dependent-vtags": [
	{"resource-id": "default-network-map",		{"resource-id": "default-network-map",
	"tag": "3ee2cb7e8d63d9fab71b9b34cbf764436315542e"},		"tag": "3ee2cb7e8d63d9fab71b9b34cbf764436315542e"},
	{"resource-id": "alt-network-map",		{"resource-id": "alt-network-map",
	skipping to change at page 43, line 27 ¶		skipping to change at line 2036 ¶
	"property-map": {		"property-map": {
	"ipv4:192.0.2.0/23": {".ISP": "BitsRus"},		"ipv4:192.0.2.0/23": {".ISP": "BitsRus"},
	"ipv4:192.0.2.0/27": {".ASN": "65543"},		"ipv4:192.0.2.0/27": {".ASN": "65543"},
	"ipv4:192.0.3.0/27": {".ASN": "65544"}		"ipv4:192.0.3.0/27": {".ASN": "65544"}
	}		}
	}		}
	10.5. Filtered Property Map Example #1		10.5. Filtered Property Map Example #1
	The following example uses the filtered property map resource to		The following example uses the filtered property map resource to
	request the "ISP", "ASN" and "state" properties for several IPv4		request the "ISP", "ASN", and "state" properties for several IPv4
	addresses.		addresses.
	Note that the value of "state" for "ipv4:192.0.2.1" is the only		Note that the value of "state" for "ipv4:192.0.2.1" is the only
	explicitly defined property; the other values are all derived by the		explicitly defined property; the other values are all derived from
	inheritance rules for Internet address entities.		the inheritance rules for Internet address entities.
	POST /propmap/lookup/inet-iacs HTTP/1.1		POST /propmap/lookup/inet-iacs HTTP/1.1
	Host: alto.example.com		Host: alto.example.com
	Accept: application/alto-propmap+json,application/alto-error+json		Accept: application/alto-propmap+json,application/alto-error+json
	Content-Length: 158		Content-Length: 158
	Content-Type: application/alto-propmapparams+json		Content-Type: application/alto-propmapparams+json
	{		{
	"entities" : [ "ipv4:192.0.2.0",		"entities" : [ "ipv4:192.0.2.0",
	"ipv4:192.0.2.1",		"ipv4:192.0.2.1",
	skipping to change at page 44, line 30 ¶		skipping to change at line 2082 ¶
	"ipv4:192.0.2.1":		"ipv4:192.0.2.1":
	{".ISP": "BitsRus", ".ASN": "65543", ".state": "PA"},		{".ISP": "BitsRus", ".ASN": "65543", ".state": "PA"},
	"ipv4:192.0.2.17":		"ipv4:192.0.2.17":
	{".ISP": "BitsRus", ".ASN": "65543", ".state": "CT"}		{".ISP": "BitsRus", ".ASN": "65543", ".state": "CT"}
	}		}
	}		}
	10.6. Filtered Property Map Example #2		10.6. Filtered Property Map Example #2
	The following example uses the filtered property map resource to		The following example uses the filtered property map resource to
	request the "ASN", "countrycode" and "state" properties for several		request the "ASN", "countrycode", and "state" properties for several
	IPv4 prefixes.		IPv4 prefixes.
	Note that the property values for both entities "ipv4:192.0.2.0/26"		Note that the property values for both entities "ipv4:192.0.2.0/26"
	and "ipv4:192.0.3.0/26" are not explicitly defined. They are		and "ipv4:192.0.3.0/26" are not explicitly defined. They are
	inherited from the entity "ipv4:192.0.2.0/23".		inherited from the entity "ipv4:192.0.2.0/23".
	Also note that some entities like "ipv4:192.0.2.0/28" and		Also note that some entities like "ipv4:192.0.2.0/28" and
	"ipv4:192.0.2.16/28" in the response are not explicitly listed in the		"ipv4:192.0.2.16/28" in the response are not explicitly listed in the
	request. The response includes them because they are refinements of		request. The response includes them because they are refinements of
	the requested entities and have different values for the requested		the requested entities and have different values for the requested
	properties.		properties.
	The entity "ipv4:192.0.4.0/26" is not included in the response,		The entity "ipv4:192.0.4.0/26" is not included in the response
	because there are neither entities which it is inherited from, nor		because there are neither entities from which it is inherited, nor
	entities inherited from it.		entities inherited from it.
	POST /propmap/lookup/inet-iacs HTTP/1.1		POST /propmap/lookup/inet-iacs HTTP/1.1
	Host: alto.example.com		Host: alto.example.com
	Accept: application/alto-propmap+json,application/alto-error+json		Accept: application/alto-propmap+json,application/alto-error+json
	Content-Length: 174		Content-Length: 174
	Content-Type: application/alto-propmapparams+json		Content-Type: application/alto-propmapparams+json
	{		{
	"entities" : [ "ipv4:192.0.2.0/26",		"entities" : [ "ipv4:192.0.2.0/26",
	skipping to change at page 46, line 6 ¶		skipping to change at line 2147 ¶
	}		}
	}		}
	10.7. Filtered Property Map Example #3		10.7. Filtered Property Map Example #3
	The following example uses the filtered property map resource to		The following example uses the filtered property map resource to
	request the "default-network-map.pid" property and the "alt-network-		request the "default-network-map.pid" property and the "alt-network-
	map.pid" property for a set of IPv4 addresses and prefixes.		map.pid" property for a set of IPv4 addresses and prefixes.
	Note that the entity "ipv4:192.0.3.0/27" is decomposed into two		Note that the entity "ipv4:192.0.3.0/27" is decomposed into two
	entities "ipv4:192.0.3.0/28" and "ipv4:192.0.3.16/28", as they have		entities: "ipv4:192.0.3.0/28" and "ipv4:192.0.3.16/28", as they have
	different "default-network-map.pid" property values.		different "default-network-map.pid" property values.
	POST /propmap/lookup/pid HTTP/1.1		POST /propmap/lookup/pid HTTP/1.1
	Host: alto.example.com		Host: alto.example.com
	Accept: application/alto-propmap+json,application/alto-error+json		Accept: application/alto-propmap+json,application/alto-error+json
	Content-Length: 222		Content-Length: 222
	Content-Type: application/alto-propmapparams+json		Content-Type: application/alto-propmapparams+json
	{		{
	"entities" : [		"entities" : [
	skipping to change at page 47, line 9 ¶		skipping to change at line 2194 ¶
	"alt-network-map.pid": "pid2"},		"alt-network-map.pid": "pid2"},
	"ipv4:192.0.3.16/28": {"default-network-map.pid": "pid4",		"ipv4:192.0.3.16/28": {"default-network-map.pid": "pid4",
	"alt-network-map.pid": "pid2"}		"alt-network-map.pid": "pid2"}
	}		}
	}		}
	10.8. Filtered Property Map Example #4		10.8. Filtered Property Map Example #4
	Here is an example of using the filtered property map to query the		Here is an example of using the filtered property map to query the
	regions for several PIDs in "default-network-map". The "region"		regions for several PIDs in "default-network-map". The "region"
	property is specified as a "self-defined" property, i.e., the values		property is specified as a self-defined property, i.e., the values of
	of this property are defined by this property map resource.		this property are defined by this property map resource.
	POST /propmap/lookup/region HTTP/1.1		POST /propmap/lookup/region HTTP/1.1
	Host: alto.example.com		Host: alto.example.com
	Accept: application/alto-propmap+json,application/alto-error+json		Accept: application/alto-propmap+json,application/alto-error+json
	Content-Length: 132		Content-Length: 132
	Content-Type: application/alto-propmapparams+json		Content-Type: application/alto-propmapparams+json
	{		{
	"entities" : ["default-network-map.pid:pid1",		"entities" : ["default-network-map.pid:pid1",
	"default-network-map.pid:pid2"],		"default-network-map.pid:pid2"],
	skipping to change at page 48, line 13 ¶		skipping to change at line 2244 ¶
	on several ANEs defined in this property map.		on several ANEs defined in this property map.
	POST /propmap/lookup/ane-dc HTTP/1.1		POST /propmap/lookup/ane-dc HTTP/1.1
	Host: alto.example.com		Host: alto.example.com
	Accept: application/alto-propmap+json,application/alto-error+json		Accept: application/alto-propmap+json,application/alto-error+json
	Content-Length: 155		Content-Length: 155
	Content-Type: application/alto-propmapparams+json		Content-Type: application/alto-propmapparams+json
	{		{
	"entities" : [".ane:dc21",		"entities" : [".ane:dc21",
	".ane:dc45.srv9",		".ane:dc45-srv9",
	".ane:dc6.srv-cluster8"],		".ane:dc6-srvcluster8"],
	"properties" : [ "storage-capacity", "cpu"]		"properties" : [ "storage-capacity", "cpu"]
	}		}
	HTTP/1.1 200 OK		HTTP/1.1 200 OK
	Content-Length: 295		Content-Length: 295
	Content-Type: application/alto-propmap+json		Content-Type: application/alto-propmap+json
	{		{
	"meta" : {		"meta" : {
	},		},
	"property-map": {		"property-map": {
	".ane:dc21":		".ane:dc21":
	{"storage-capacity" : 40000, "cpu" : 500},		{"storage-capacity" : 40000, "cpu" : 500},
	".ane:dc45.srv9":		".ane:dc45-srv9":
	{"storage-capacity" : 100, "cpu" : 20},		{"storage-capacity" : 100, "cpu" : 20},
	".ane:dc6.srv-cluster8":		".ane:dc6-srvcluster8":
	{"storage-capacity" : 6000, "cpu" : 100}		{"storage-capacity" : 6000, "cpu" : 100}
	}		}
	}		}
	11. Security Considerations		11. Security Considerations
	Both Property Map and Filtered Property Map defined in this document		Both property map and filtered property map defined in this document
	fit into the architecture of the ALTO base protocol, and hence the		fit into the architecture of the ALTO base protocol, and hence the
	Security Considerations (Section 15 of [RFC7285]) of the base		Security Considerations (Section 15 of [RFC7285]) of the base
	protocol fully apply: authenticity and integrity of ALTO information		protocol fully apply: authenticity and integrity of ALTO information
	(i.e., authenticity and integrity of Property Maps), potential		(i.e., authenticity and integrity of property maps), potential
	undesirable guidance from authenticated ALTO information (e.g.,		undesirable guidance from authenticated ALTO information (e.g.,
	potentially imprecise or even wrong value of a property such as geo-		potentially imprecise or even wrong value of a property such as geo-
	location), confidentiality of ALTO information (e.g., exposure of a		location), confidentiality of ALTO information (e.g., exposure of a
	potentially sensitive entity property such as geo-location), privacy		potentially sensitive entity property such as geo-location), privacy
	for ALTO users, and availability of ALTO services should all be		for ALTO users, and availability of ALTO services should all be
	considered.		considered.
	ALTO clients using this extension should in addition be aware that		ALTO clients using this extension should in addition be aware that
	the entity properties they require may convey more details than the		the entity properties they require may convey more details than the
	endpoint properties conveyed by using [RFC7285]. Client requests may		endpoint properties conveyed by using [RFC7285]. Client requests may
	reveal details on their activity or plans thereof, that a malicious		reveal details of their activity or plans thereof such that a
	Server, that is in a position to do so, may monetize or use for		malicious Server, which is in a position to do so, may monetize or
	attacks or undesired surveillance. Likewise, ALTO Servers expose		use for attacks or undesired surveillance. Likewise, ALTO Servers
	entities and properties related to specific parts of the		expose entities and properties related to specific parts of the
	infrastructure that reveal details on capabilities, locations, or		infrastructure that reveal details of capabilities, locations, or
	resource availability. These details may be maliciously used for		resource availability. These details may be maliciously used for
	competition purposes, or to cause resource shortage or undesired		competition purposes, or to cause resource shortage or undesired
	publication.		publication.
	To address these concerns, the Property Maps provided by this		To address these concerns, the property maps provided by this
	extension require additional attention on two security considerations		extension require additional attention to two security considerations
	discussed in [RFC7285]: "potential undesirable guidance from		discussed in: Section 15.2 ("Potential Undesirable Guidance from
	authenticated ALTO information" (Section 15.2 of [RFC7285]) and		Authenticated ALTO Information") of [RFC7285] and Section 15.3
	"confidentiality of ALTO information" (Section 15.3 of [RFC7285]).		("Confidentiality of ALTO Information") of [RFC7285]. Threats to the
	Threats to the availability of the ALTO Service caused by highly		availability of the ALTO service caused by highly demanding queries
	demanding queries should be addressed as specified in Section 15.5 of		should be addressed as specified in Section 15.5 of [RFC7285].
	[RFC7285].
	* Potential undesirable guidance from authenticated ALTO		* Potential undesirable guidance from authenticated ALTO
	information: it can be caused by Property values that change over		information: this can be caused by Property values that change
	time and thus lead to performance degradation or system rejection		over time and thus lead to performance degradation or system
	of application requests.		rejection of application requests.
	To avoid these consequences, a more robust ALTO client should		To avoid these consequences, a more robust ALTO client should
	adopt and extend protection strategies specified in Section 15.2		adopt and extend protection strategies specified in Section 15.2
	of [RFC7285]. For example, to be notified immediately when a		of [RFC7285]. For example, to be notified immediately when a
	particular ALTO value that the Client depends on changes, it is		particular ALTO value that the Client depends on changes, it is
	RECOMMENDED that both the ALTO Client and ALTO Server using this		RECOMMENDED that both the ALTO Client and ALTO Server using this
	extension implement "Application-Layer Traffic Optimization (ALTO)		extension implement "Application-Layer Traffic Optimization (ALTO)
	Incremental Updates Using Server-Sent Events (SSE)" [RFC8895].		Incremental Updates Using Server-Sent Events (SSE)" [RFC8895].
	* Confidentiality of ALTO information: as discussed in Section 15 of		* Confidentiality of ALTO information: as discussed in Section 15 of
	[RFC7285], properties may have sensitive customer-specific		[RFC7285], properties may have sensitive customer-specific
	information. If this is the case, an ALTO Server may limit access		information. If this is the case, an ALTO Server may limit access
	to those properties by providing several different property maps.		to those properties by providing several different property maps.
	For non-sensitive properties, the ALTO Server would provide a URI		For a nonsensitive properties, the ALTO Server would provide a URI
	which accepts requests from any client. Sensitive properties, on		that accepts requests from any client. Sensitive properties, on
	the other hand, would only be available via a secure URI which		the other hand, would only be available via a secure URI that
	would require client authentication. Another way is to expose		would require client authentication. Another way is to expose
	highly abstracted coarse-grained property values to all Clients		highly abstracted, coarse-grained property values to all Clients
	while restricting access to URIs exposing more fine-grained values		while restricting access to URIs that expose more fine-grained
	to authorized Clients. Restricted access URIs may be gathered in		values to authorized Clients. Restricted access URIs may be
	delegate IRDs as specified in Section 9.2.4 of [RFC7285].		gathered in delegate IRDs as specified in Section 9.2.4 of
			[RFC7285].
	Also, while technically this document does not introduce any		Also, while technically this document does not introduce any
	security risks not inherent in the Endpoint Property Service		security risks not inherent in the Endpoint Property Service
	defined by [RFC7285], the GET-mode property map resource defined		defined by [RFC7285], the GET-mode property map resource defined
	in this document does make it easier for a client to download		in this document does make it easier for a client to download
	large numbers of property values. Accordingly, an ALTO Server		large numbers of property values. Accordingly, an ALTO Server
	should limit GET-mode property maps to properties that do not		should limit GET-mode property maps to properties that do not
	contain sensitive data.		contain sensitive data.
	Section 12 of this document specifies that the ALTO service		Section 12 of this document specifies that the ALTO service
	provider MUST be aware of the potential sensitivity of exposed		provider MUST be aware of the potential sensitivity of exposed
	entity domains and properties. Section 12.2.2. (ALTO Entity		entity domains and properties. Section 12.3.2 (ALTO Entity Domain
	Domain Type Registration Process) of this document specifies that		Type Registration Process) of this document specifies that when
	when the registration of an entity domain type is requested at the		the registration of an entity domain type is requested of IANA,
	IANA, the request MUST include security considerations that show		the request MUST include security considerations that show
	awareness of how the exposed entity addresses may be related to		awareness of how the exposed entity addresses may be related to
	private information about an ALTO client or an infrastructure		private information about an ALTO client or an infrastructure
	service provider. Likewise, Section 12.3. (ALTO Entity Property		service provider. Likewise, Section 12.4 (ALTO Entity Property
	Type Registry) of this document specifies that when the		Types Registry) of this document specifies that when the
	registration of a property type is requested at the IANA, the		registration of a property type is requested of IANA, the request
	request MUST include security considerations that explain why this		MUST include security considerations that explain why this
	property type is required for ALTO-based operations.		property type is required for ALTO-based operations.
	The risk of ALTO information being leaked to malicious Clients or		The risk of ALTO information being leaked to malicious Clients or
	third parties is addressed similarly to Section 7 of [RFC8896].		third parties is addressed similarly to Section 7 of [RFC8896].
	ALTO clients and servers SHOULD support TLS 1.3 [RFC8446].		ALTO clients and servers SHOULD support TLS 1.3 [RFC8446].
	12. IANA Considerations		12. IANA Considerations
	This document defines additional application/alto-* media types, that		This document defines additional application/alto-* media types,
	are listed in Table 1. It defines an ALTO Entity Domain Type		which are listed in Table 8. It defines the "ALTO Entity Domain
	Registry that extends the ALTO Address Type Registry defined in		Types" registry that extends the "ALTO Address Types" registry
	[RFC7285]. It also defines an ALTO Entity Property Type Registry		defined in [RFC7285]. It also defines the "ALTO Entity Property
	that extends the ALTO endpoint property registry defined in		Types" registry that extends the "ALTO Endpoint Property Types"
	[RFC7285].		registry defined in [RFC7285].
	+=============+=========================+===============+		+=============+=========================+===============+
	| Type | Subtype | Specification |		| Type | Subtype | Specification |
	+=============+=========================+===============+		+=============+=========================+===============+
	| application | alto-propmap+json | Section 7.1 |		| application | alto-propmap+json | Section 7.1 |
	+-------------+-------------------------+---------------+		+-------------+-------------------------+---------------+
	| application | alto-propmapparams+json | Section 8.3 |		| application | alto-propmapparams+json | Section 8.3 |
	+-------------+-------------------------+---------------+		+-------------+-------------------------+---------------+
	Table 1: Additional ALTO Media Types.		Table 8: Additional ALTO Media Types
	12.1. application/alto-propmap+json Media Type		12.1. application/alto-propmap+json Media Type
	Type name:		Type name:
	application		application
	Subtype name:		Subtype name:
	alto-propmap+json		alto-propmap+json
	Required parameters:		Required parameters:
	skipping to change at page 51, line 36 ¶		skipping to change at line 2403 ¶
	and Section 11 of this document.		and Section 11 of this document.
	Interoperability considerations:		Interoperability considerations:
	n/a		n/a
	Published specification:		Published specification:
	This document is the specification for this media type. See		This document is the specification for this media type. See
	Section 7.1.		Section 7.1.
	Applications that use this media type:		Applications that use this media type:
	ALTO servers and ALTO clients [RFC7285], either stand alone or		ALTO servers and ALTO clients [RFC7285], either standalone or
	embedded within other applications, when the queried resource is a		embedded within other applications, when the queried resource is a
	property map, whether filtered or not.		property map, whether filtered or not.
	Fragment identifier considerations:		Fragment identifier considerations:
	n/a		n/a
	Additional information:		Additional information:
	Magic number(s): n/a		Magic number(s): n/a
	File extension(s): n/a		File extension(s): n/a
	skipping to change at page 52, line 15 ¶		skipping to change at line 2430 ¶
	Intended usage:		Intended usage:
	COMMON		COMMON
	Restrictions on usage:		Restrictions on usage:
	n/a		n/a
	Author:		Author:
	See Authors' Addresses section.		See Authors' Addresses section.
	Change controller:		Change controller:
	Internet Engineering Task Force (mailto:iesg@ietf.org).		Internet Engineering Task Force (iesg@ietf.org).
	12.2. alto-propmapparams+json Media Type		12.2. alto-propmapparams+json Media Type
	Type name:		Type name:
	application		application
	Subtype name:		Subtype name:
	alto-propmapparams+json		alto-propmapparams+json
	Required parameters:		Required parameters:
	skipping to change at page 52, line 48 ¶		skipping to change at line 2463 ¶
	and Section 11 of this document.		and Section 11 of this document.
	Interoperability considerations:		Interoperability considerations:
	n/a		n/a
	Published specification:		Published specification:
	This document is the specification for this media type. See		This document is the specification for this media type. See
	Section 8.3.		Section 8.3.
	Applications that use this media type:		Applications that use this media type:
	ALTO servers and ALTO clients [RFC7285], either stand alone or		ALTO servers and ALTO clients [RFC7285], either standalone or
	embedded within other applications, when the queried resource is a		embedded within other applications, when the queried resource is a
	filtered property map. This media-type indicates the data format		filtered property map. This media type indicates the data format
	used by the ALTO client to supply the property map filtering		used by the ALTO client to supply the property map filtering
	parameters.		parameters.
	Fragment identifier considerations:		Fragment identifier considerations:
	n/a		n/a
	Additional information:		Additional information:
	Magic number(s): n/a		Magic number(s): n/a
	File extension(s): n/a		File extension(s): n/a
	skipping to change at page 53, line 28 ¶		skipping to change at line 2492 ¶
	Intended usage:		Intended usage:
	COMMON		COMMON
	Restrictions on usage:		Restrictions on usage:
	n/a		n/a
	Author:		Author:
	See Authors' Addresses section.		See Authors' Addresses section.
	Change controller:		Change controller:
	Internet Engineering Task Force (mailto:iesg@ietf.org).		Internet Engineering Task Force (iesg@ietf.org).
	12.3. ALTO Entity Domain Type Registry		12.3. ALTO Entity Domain Types Registry
	This document requests IANA to create and maintain the "ALTO Entity		IANA has created and will maintain the "ALTO Entity Domain Types"
	Domain Type Registry", listed in Table 2. The first line lists		registry listed in Table 9. The first row lists information items
	information items that must be provided with each registered entity		that must be provided with each registered entity domain type.
	domain type. Section 12.3.2 specifies how to document these items		Section 12.3.2 specifies how to document these items and in addition
	and provides guidance on the security considerations item that must		provides guidance on the security considerations item that must be
	be documented in addition.		documented.
	+==========+===========+=============+======================+=======+		+==========+===========+=============+======================+=======+
	|Identifier|Entity |Hierarchy & |Media Type of Defining|Mapping|		|Identifier|Entity |Hierarchy and|Media Type of Defining|Mapping|
	| |Identifier |Inheritance |Resource |to ALTO|		| |Identifier |Inheritance |Resource |to ALTO|
	| |Encoding | | |Address|		| |Encoding | | |Address|
	| | | | |Type |		| | | | |Type |
	+==========+===========+=============+======================+=======+		+==========+===========+=============+======================+=======+
	|ipv4 |See Section|See |application/alto- |true |		|ipv4 |See Section|See |application/alto- |true |
	| |6.1.1 |Section 6.1.3|networkmap+json | |		| |6.1.1 |Section 6.1.3|networkmap+json | |
	+----------+-----------+-------------+----------------------+-------+		+----------+-----------+-------------+----------------------+-------+
	|ipv6 |See Section|See |application/alto- |true |		|ipv6 |See Section|See |application/alto- |true |
	| |6.1.2 |Section 6.1.3|networkmap+json | |		| |6.1.2 |Section 6.1.3|networkmap+json | |
	+----------+-----------+-------------+----------------------+-------+		+----------+-----------+-------------+----------------------+-------+
	|pid |See |None |application/alto- |false |		|pid |See |None |application/alto- |false |
	| |Section 6.2| |networkmap+json | |		| |Section 6.2| |networkmap+json | |
	+----------+-----------+-------------+----------------------+-------+		+----------+-----------+-------------+----------------------+-------+
	Table 2: ALTO Entity Domain Types		Table 9: ALTO Entity Domain Types
	This registry serves two purposes. First, it ensures uniqueness of		This registry serves two purposes. First, it ensures uniqueness of
	identifiers referring to ALTO entity domain types. Second, it states		identifiers referring to ALTO entity domain types. Second, it states
	the requirements for allocated entity domain types.		the requirements for allocated entity domain types.
	As specified in Section 5.1.1, identifiers prefixed with "priv:" are		As specified in Section 5.1.1, identifiers prefixed with "priv:" are
	reserved for Private Use without a need to register with IANA		reserved for Private Use without a need to register with IANA
	12.3.1. Consistency Procedure between ALTO Address Type Registry and		12.3.1. Consistency Procedure between ALTO Address Types Registry and
	ALTO Entity Domain Type Registry		ALTO Entity Domain Types Registry
	One potential issue of introducing the "ALTO Entity Domain Type		One potential issue of introducing the "ALTO Entity Domain Types"
	Registry" is its relationship with the "ALTO Address Types Registry"		registry is its relationship with the "ALTO Address Types" registry
	already defined in Section 14.4 of [RFC7285]. In particular, the		already defined in Section 14.4 of [RFC7285]. In particular, the
	entity identifier of a type of an entity domain registered in the		entity identifier of a type of an entity domain registered in the
	"ALTO Entity Domain Type Registry" MAY match an address type defined		"ALTO Entity Domain Types" registry MAY match an address type defined
	in "ALTO Address Type Registry". It is necessary to precisely define		in "ALTO Address Types" registry. It is necessary to precisely
	and guarantee the consistency between "ALTO Address Type Registry"		define and guarantee the consistency between "ALTO Address Types"
	and "ALTO Entity Domain Registry".		registry and "ALTO Entity Domain Types" registry.
	We define that the ALTO Entity Domain Type Registry is consistent		We define that the "ALTO Entity Domain Types" registry is consistent
	with ALTO Address Type Registry if two conditions are satisfied:		with "ALTO Address Types" registry if two conditions are satisfied:
	* When an address type is already or able to be registered in the		* When an address type is already registered or is able to be
	ALTO Address Type Registry [RFC7285], the same identifier MUST be		registered in the "ALTO Address Types" registry [RFC7285], the
	used when a corresponding entity domain type is registered in the		same identifier MUST be used when a corresponding entity domain
	ALTO Entity Domain Type Registry.		type is registered in the "ALTO Entity Domain Types" registry.
	* If an ALTO entity domain type has the same identifier as an ALTO		* If an ALTO entity domain type has the same identifier as an ALTO
	address type, their addresses encoding MUST be compatible.		address type, their address encodings MUST be compatible.
	To achieve this consistency, the following items MUST be checked		To achieve this consistency, the following items MUST be checked
	before registering a new ALTO entity domain type in a future		before registering a new ALTO entity domain type in a future
	document:		document:
	* Whether the ALTO Address Type Registry contains an address type		* Whether the "ALTO Address Types" registry contains an address type
	that can be used as an identifier for the candidate entity domain		that can be used as an identifier for the candidate entity domain
	type identifier. This has been done for the identifiers "ipv4"		type identifier. This has been done for the identifiers "ipv4"
	and "ipv6" of Table 2.		and "ipv6" of Table 9.
	* Whether the candidate entity domain type identifier can		* Whether the candidate entity domain type identifier can
	potentially be an endpoint address type, as defined in Sections		potentially be an endpoint address type, as defined in Sections
	2.1 and 2.2 of [RFC7285].		2.1 and 2.2 of [RFC7285].
	When a new ALTO entity domain type is registered, the consistency		When a new ALTO entity domain type is registered, the consistency
	with the ALTO Address Type Registry MUST be ensured by the following		with the "ALTO Address Types" registry MUST be ensured by the
	procedure:		following procedure:
	* Test: Do corresponding entity domain type identifiers match a		* Test: Do corresponding entity domain type identifiers match a
	known "network" address type?		known "network" address type?
	- If yes (e.g., cell, MAC or socket addresses):		- If yes (e.g., cell, MAC, or socket addresses):
	o Test: Is such an address type present in the ALTO Address		o Test: Is such an address type present in the "ALTO Address
	Type Registry?		Types" registry?
	+ If yes: Set the new ALTO entity domain type identifier to		+ If yes: Set the new ALTO entity domain type identifier to
	be the found ALTO address type identifier.		be the found ALTO address type identifier.
	+ If no: Define a new ALTO entity domain type identifier		+ If no: Define a new ALTO entity domain type identifier
	and use it to register a new address type in the ALTO		and use it to register a new address type in the "ALTO
	Address Type Registry following Section 14.4 of		Address Types" registry following Section 14.4 of
	[RFC7285].		[RFC7285].
	o Use the new ALTO entity domain type identifier to register a		o Use the new ALTO entity domain type identifier to register a
	new ALTO entity domain type in the ALTO Entity Domain Type		new ALTO entity domain type in the "ALTO Entity Domain
	Registry following Section 12.3.2 of this document.		Types" registry following Section 12.3.2 of this document.
	- If no (e.g., pid name, ane name or country code): Proceed with		- If no (e.g., PID name, ANE name, or "countrycode"): Proceed
	the ALTO Entity Domain Type registration as described in		with the ALTO Entity Domain Type registration as described in
	Section 12.3.2.		Section 12.3.2.
	12.3.2. ALTO Entity Domain Type Registration Process		12.3.2. ALTO Entity Domain Type Registration Process
	New ALTO entity domain types are assigned after IETF Review [RFC8126]		New ALTO entity domain types are assigned after IETF Review [RFC8126]
	to ensure that proper documentation regarding the new ALTO entity		to ensure that proper documentation regarding the new ALTO entity
	domain types and their security considerations has been provided.		domain types and their security considerations has been provided.
	RFCs defining new entity domain types MUST indicate how an entity in		RFCs defining new entity domain types MUST indicate how an entity in
	a registered type of domain is encoded as an EntityID, and, if		a registered type of domain is encoded as an EntityID and, if
	applicable, the rules defining the entity hierarchy and property		applicable, provide the rules for defining the entity hierarchy and
	inheritance. Updates and deletions of ALTO entity domains types		property inheritance. Updates and deletions of ALTO entity domains
	follow the same procedure.		types follow the same procedure.
	Registered ALTO entity domain type identifiers MUST conform to the		Registered ALTO entity domain type identifiers MUST conform to the
	syntactical requirements specified in Section 5.1.2. Identifiers are		syntactical requirements specified in Section 5.1.2. Identifiers are
	to be recorded and displayed as strings.		to be recorded and displayed as strings.
	Requests to the IANA to add a new value to the Entity Domain Type		Requests to IANA to add a new value to the "ALTO Entity Domain Types"
	registry MUST include the following information:		registry MUST include the following information:
	* Identifier: The name of the desired ALTO entity domain type.		Identifier: The name of the desired ALTO entity domain type.
	* Entity Identifier Encoding: The procedure for encoding the		Entity Identifier Encoding: The procedure for encoding the
	identifier of an entity of the registered domain type as an		identifier of an entity of the registered domain type as an
	EntityID (see Section 5.1.3). If corresponding entity identifiers		EntityID (see Section 5.1.3). If corresponding entity identifiers
	of an entity domain type match a known "network" address type, the		of an entity domain type match a known "network" address type, the
	Entity Identifier Encoding of this domain identifier MUST include		Entity Identifier Encoding of this domain identifier MUST include
	both Address Encoding and Prefix Encoding of the same identifier		both Address Encoding and Prefix Encoding of the same identifier
	registered in the ALTO Address Type Registry [RFC7285]. To define		registered in the "ALTO Address Types" registry [RFC7285]. To
	properties, an individual entity identifier and the corresponding		define properties, an individual entity identifier and the
	full-length prefix MUST be considered aliases for the same entity.		corresponding full-length prefix MUST be considered aliases for
			the same entity.
	* Hierarchy: If the entities form a hierarchy, the procedure for		Hierarchy: If the entities form a hierarchy, the procedure for
	determining that hierarchy.		determining that hierarchy.
	* Inheritance: If entities can inherit property values from other		Inheritance: If entities can inherit property values from other
	entities, the procedure for determining that inheritance.		entities, the procedure for determining that inheritance.
	* Media type of defining information resource: Some entity domain		Media type of defining information resource: Some entity domain
	types allow an entity domain name to be combined with an		types allow an entity domain name to be combined with an
	information resource name to define a resource-specific entity		information resource name to define a resource-specific entity
	domain. Such an information resource is called "defining		domain. Such an information resource is called a "defining
	information resource", defined in Section 4.6. For each entity		information resource" and is defined in Section 4.6. For each
	domain type, the potential defining information resources have one		entity domain type, the potential defining information resources
	common media type. This unique common media type is specific to		have one common media type. This unique common media type is
	the entity domain type and MUST be specified.		specific to the entity domain type and MUST be specified.
	* Mapping to ALTO Address Type: A boolean value to indicate if the		Mapping to ALTO Address Type: A boolean value to indicate if the
	entity domain type can be mapped to the ALTO address type with the		entity domain type can be mapped to the ALTO address type with the
	same identifier.		same identifier.
	* Security Considerations: In some usage scenarios, entity		Security Considerations: In some usage scenarios, entity identifiers
	identifiers carried in ALTO Protocol messages may reveal		carried in ALTO Protocol messages may reveal information about an
	information about an ALTO client or an ALTO service provider.		ALTO client or an ALTO service provider. Applications and ALTO
	Applications and ALTO service providers using addresses of the		service providers using addresses of the registered type should be
	registered type should be cognizant of how (or if) the addressing		cognizant of how (or if) the addressing scheme relates to private
	scheme relates to private information and network proximity.		information and network proximity.
	This specification requests registration of the identifiers "ipv4",		IANA has registered the identifiers "ipv4", "ipv6", and "pid", as
	"ipv6" and "pid", as shown in Table 2.		shown in Table 9.
	12.4. ALTO Entity Property Type Registry		12.4. ALTO Entity Property Types Registry
	This document requests IANA to create and maintain the "ALTO Entity		IANA has created and will maintain the "ALTO Entity Property Types"
	Property Type Registry", listed in Table 3.		registry, which is listed in Table 10.
	This registry extends the "ALTO Endpoint Property Type Registry",		This registry extends the "ALTO Endpoint Property Types" registry,
	defined in [RFC7285], in that a property type is defined on one or		defined in [RFC7285], in that a property type is defined for one or
	more entity domains, rather than just on IPv4 and IPv6 Internet		more entity domains, rather than just for IPv4 and IPv6 Internet
	address domains. An entry in this registry is an ALTO entity		address domains. An entry in this registry is an ALTO entity
	property type defined in Section 5.2.1. Thus, a registered ALTO		property type defined in Section 5.2.1. Thus, a registered ALTO
	entity property type identifier MUST conform to the syntactical		entity property type identifier MUST conform to the syntactical
	requirements specified in that section.		requirements specified in that section.
	As specified in Section 5.2.1, identifiers prefixed with "priv:" are		As specified in Section 5.2.1, identifiers prefixed with "priv:" are
	reserved for Private Use without a need to register with IANA.		reserved for Private Use without a need to register with IANA.
	The first line of Table 3 lists information items that must be		The first row of Table 10 lists information items that must be
	provided with each registered entity property type.		provided with each registered entity property type.
	+============+====================+=================================+		+============+====================+=================================+
	| Identifier | Intended Semantics | Media Type of |		| Identifier | Intended Semantics | Media Type of |
	| | | Defining Resource |		| | | Defining Resource |
	+============+====================+=================================+		+============+====================+=================================+
	| pid | See Section 7.1.1 | application/alto- |		| pid | See Section 7.1.1 | application/alto- |
	| | of [RFC7285] | networkmap+json |		| | of [RFC7285] | networkmap+json |
	+------------+--------------------+---------------------------------+		+------------+--------------------+---------------------------------+
	Table 3: ALTO Entity Property Types.		Table 10: ALTO Entity Property Types
	New ALTO entity property types are assigned after IETF Review		New ALTO entity property types are assigned after IETF Review
	[RFC8126] to ensure that proper documentation regarding the new ALTO		[RFC8126] to ensure that proper documentation regarding the new ALTO
	entity property types and their security considerations has been		entity property types and their security considerations has been
	provided. RFCs defining new entity property types SHOULD indicate		provided. RFCs defining new entity property types SHOULD indicate
	how a property of a registered type is encoded as a property name.		how a property of a registered type is encoded as a property name.
	Updates and deletions of ALTO entity property types follow the same		Updates and deletions of ALTO entity property types follow the same
	procedure.		procedure.
	Requests to the IANA to add a new value to the registry MUST include		Requests to IANA to add a new value to the registry MUST include the
	the following information:		following information:
	* Identifier: The identifier for the desired ALTO entity property		Identifier: The identifier for the desired ALTO entity property
	type. The format MUST be as defined in Section 5.2.1 of this		type. The format MUST be as defined in Section 5.2.1 of this
	document.		document.
	* Intended Semantics: ALTO entity properties carry with them		Intended Semantics: ALTO entity properties carry with them semantics
	semantics to guide their usage by ALTO clients. Hence, a document		to guide their usage by ALTO clients. Hence, a document defining
	defining a new type SHOULD provide guidance to both ALTO service		a new type SHOULD provide guidance to both ALTO service providers
	providers and applications utilizing ALTO clients as to how values		and applications utilizing ALTO clients as to how values of the
	of the registered ALTO entity property should be interpreted.		registered ALTO entity property should be interpreted.
	* Media type of defining information resource: when the property		Media type of defining information resource: when the property type
	type allows values to be defined relative to a given information		allows values to be defined relative to a given information
	resource, the latter is referred to as the "defining information		resource, the latter is referred to as the "defining information
	resource", see description in Section 4.7. For each property		resource"; see the description in Section 4.7. For each property
	type, the potential defining information resources have one common		type, the potential defining information resources have one common
	media type. This unique common media type is specific to the		media type. This unique common media type is specific to the
	property type and MUST be specified.		property type and MUST be specified.
	* Security Considerations: ALTO entity properties expose information		Security Considerations: ALTO entity properties expose information
	to ALTO clients. ALTO service providers should be cognizant of		to ALTO clients. ALTO service providers should be cognizant of
	the security ramifications related to the exposure of an entity		the security ramifications related to the exposure of an entity
	property.		property.
	In security considerations, the request should also discuss the		In security considerations, the request should also discuss the
	sensitivity of the information, and why it is required for ALTO-based		sensitivity of the information and why it is required for ALTO-based
	operations. Regarding this discussion, the request SHOULD follow the		operations. Regarding this discussion, the request SHOULD follow the
	recommendations of Section 14.3. ALTO Endpoint Property Type		recommendations of the "ALTO Endpoint Property Types" registry in
	Registry in [RFC7285].		Section 14.3 of [RFC7285].
	This document requests registration of the identifier "pid", listed		IANA has registered the identifier "pid", which is listed in
	in Table 3. Semantics for this property are documented in		Table 10. Semantics for this property are documented in
	Section 7.1.1 of [RFC7285]. No security issues related to the		Section 7.1.1 of [RFC7285]. No security issues related to the
	exposure of a "pid" identifier are considered, as it is exposed with		exposure of a "pid" identifier are considered, as it is exposed with
	the Network Map Service defined and mandated in [RFC7285].		the Network Map Service defined and mandated in [RFC7285].
	13. Acknowledgments		13. References
	The authors would like to thank Dawn Chen, and Shenshen Chen for
	their contributions to earlier drafts. Thank you also to Qiao Xiang,
	Shawn Lin, Xin Wang and Vijay Gurbani for fruitful discussions.
	Last, big thanks to Danny Perez and Luis Contreras for their
	substantial Working Group review feedback and suggestions to improve
	this document, to Vijay Gurbani, ALTO WG Chair and Martin Duke,
	Transport Area Director, for their thorough review, discussions,
	guidance and shepherding, that further helped to enrich this
	document.
	14. References
	14.1. Normative References		13.1. Normative References
	[ISO3166-1]		[ISO3166-1]
	ISO (International Organization for Standardization), .,		International Organization for Standardization, "Codes for
	"ISO 3166-1: Codes for the representation of names of		the representation of names of countries and their
	countries and their subdivisions -- Part 1: Country		subdivisions -- Part 1: Country codes", ISO 3166-1:2020,
	codes", 2020.		August 2020.
	[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate		[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
	Requirement Levels", BCP 14, RFC 2119,		Requirement Levels", BCP 14, RFC 2119,
	DOI 10.17487/RFC2119, March 1997,		DOI 10.17487/RFC2119, March 1997,
	<https://www.rfc-editor.org/info/rfc2119>.		<https://www.rfc-editor.org/info/rfc2119>.
	[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform		[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
	Resource Identifier (URI): Generic Syntax", STD 66,		Resource Identifier (URI): Generic Syntax", STD 66,
	RFC 3986, DOI 10.17487/RFC3986, January 2005,		RFC 3986, DOI 10.17487/RFC3986, January 2005,
	<https://www.rfc-editor.org/info/rfc3986>.		<https://www.rfc-editor.org/info/rfc3986>.
	[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing		[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing
	Architecture", February 2006.		Architecture", RFC 4291, DOI 10.17487/RFC4291, February
			2006, <https://www.rfc-editor.org/info/rfc4291>.
	[RFC4632] Fuller, V. and T. Li, "Classless Inter-domain Routing		[RFC4632] Fuller, V. and T. Li, "Classless Inter-domain Routing
	(CIDR): The Internet Address Assignment and Aggregation		(CIDR): The Internet Address Assignment and Aggregation
	Plan", BCP 122, RFC 4632, DOI 10.17487/RFC4632, August		Plan", BCP 122, RFC 4632, DOI 10.17487/RFC4632, August
	2006, <https://www.rfc-editor.org/info/rfc4632>.		2006, <https://www.rfc-editor.org/info/rfc4632>.
	[RFC5952] Kawamura, S. and M. Kawashima, "A Recommendation for IPv6		[RFC5952] Kawamura, S. and M. Kawashima, "A Recommendation for IPv6
	Address Text Representation", RFC 5952,		Address Text Representation", RFC 5952,
	DOI 10.17487/RFC5952, August 2010,		DOI 10.17487/RFC5952, August 2010,
	<https://www.rfc-editor.org/info/rfc5952>.		<https://www.rfc-editor.org/info/rfc5952>.
	skipping to change at page 60, line 23 ¶		skipping to change at line 2790 ¶
	[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol		[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
	Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,		Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
	<https://www.rfc-editor.org/info/rfc8446>.		<https://www.rfc-editor.org/info/rfc8446>.
	[RFC8895] Roome, W. and Y. Yang, "Application-Layer Traffic		[RFC8895] Roome, W. and Y. Yang, "Application-Layer Traffic
	Optimization (ALTO) Incremental Updates Using Server-Sent		Optimization (ALTO) Incremental Updates Using Server-Sent
	Events (SSE)", RFC 8895, DOI 10.17487/RFC8895, November		Events (SSE)", RFC 8895, DOI 10.17487/RFC8895, November
	2020, <https://www.rfc-editor.org/info/rfc8895>.		2020, <https://www.rfc-editor.org/info/rfc8895>.
	14.2. Informative References		13.2. Informative References
	[I-D.ietf-alto-cdni-request-routing-alto]
	Seedorf, J., Yang, Y., Ma, K., Peterson, J., and J. Zhang,
	"Content Delivery Network Interconnection (CDNI) Request
	Routing: CDNI Footprint and Capabilities Advertisement
	using ALTO", Work in Progress, Internet-Draft, draft-ietf-
	alto-cdni-request-routing-alto-16, 12 January 2021,
	<http://www.ietf.org/internet-drafts/draft-ietf-alto-cdni-
	request-routing-alto-16.txt>.
	[I-D.ietf-alto-path-vector]		[PATH-VECTOR]
	Gao, K., Lee, Y., Randriamasy, S., Yang, Y., and J. Zhang,		Gao, K., Lee, Y., Randriamasy, S., Yang, Y. R., and J. J.
	"ALTO Extension: Path Vector", Work in Progress, Internet-		Zhang, "An ALTO Extension: Path Vector", Work in Progress,
	Draft, draft-ietf-alto-path-vector-13, 20 November 2020,		Internet-Draft, draft-ietf-alto-path-vector-25, 20 March
	<http://www.ietf.org/internet-drafts/draft-ietf-alto-path-		2022, <https://datatracker.ietf.org/doc/html/draft-ietf-
	vector-13.txt>.		alto-path-vector-25>.
	[RFC3849] Huston, G., Lord, A., and P. Smith, "IPv6 Address Prefix		[RFC3849] Huston, G., Lord, A., and P. Smith, "IPv6 Address Prefix
	Reserved for Documentation", July 2004.		Reserved for Documentation", RFC 3849,
			DOI 10.17487/RFC3849, July 2004,
			<https://www.rfc-editor.org/info/rfc3849>.
	[RFC5511] Farrel, A., "Routing Backus-Naur Form (RBNF): A Syntax		[RFC5511] Farrel, A., "Routing Backus-Naur Form (RBNF): A Syntax
	Used to Form Encoding Rules in Various Routing Protocol		Used to Form Encoding Rules in Various Routing Protocol
	Specifications", April 2009.		Specifications", RFC 5511, DOI 10.17487/RFC5511, April
			2009, <https://www.rfc-editor.org/info/rfc5511>.
	[RFC5737] Arkko, J., Cotton, M., and L. Vegoda, "IPv4 Address Blocks		[RFC5737] Arkko, J., Cotton, M., and L. Vegoda, "IPv4 Address Blocks
	Reserved for Documentation", January 2010.		Reserved for Documentation", RFC 5737,
			DOI 10.17487/RFC5737, January 2010,
			<https://www.rfc-editor.org/info/rfc5737>.
	[RFC7921] Atlas, A., Halpern, J., Hares, S., Ward, D., and T.		[RFC7921] Atlas, A., Halpern, J., Hares, S., Ward, D., and T.
	Nadeau, "An Architecture for the Interface to the Routing		Nadeau, "An Architecture for the Interface to the Routing
	System", RFC 7921, DOI 10.17487/RFC7921, June 2016,		System", RFC 7921, DOI 10.17487/RFC7921, June 2016,
	<https://www.rfc-editor.org/info/rfc7921>.		<https://www.rfc-editor.org/info/rfc7921>.
	[RFC8896] Randriamasy, S., Yang, R., Wu, Q., Deng, L., and N.		[RFC8896] Randriamasy, S., Yang, R., Wu, Q., Deng, L., and N.
	Schwan, "Application-Layer Traffic Optimization (ALTO)		Schwan, "Application-Layer Traffic Optimization (ALTO)
	Cost Calendar", RFC 8896, DOI 10.17487/RFC8896, November		Cost Calendar", RFC 8896, DOI 10.17487/RFC8896, November
	2020, <https://www.rfc-editor.org/info/rfc8896>.		2020, <https://www.rfc-editor.org/info/rfc8896>.
	Appendix A. Features introduced with the Entity Property Maps extension		[RFC9241] Seedorf, J., Yang, Y., Ma, K., Peterson, J., and J. Zhang,
			"Content Delivery Network Interconnection (CDNI) Footprint
			and Capabilities Advertisement Using Application-Layer
			Traffic Optimization (ALTO)", RFC 9241,
			DOI 10.17487/RFC9241, July 2022,
			<https://www.rfc-editor.org/info/rfc9241>.
	The Entity Property Maps extension described in this document		Appendix A. Features Introduced with the Entity Property Maps Extension
			The entity property maps extension described in this document
	introduces a number of features that are summarized in table below.		introduces a number of features that are summarized in table below.
	The first column provides the name of the feature. The second column		The first column provides the name of the feature. The second column
	provides the section number of this document that gives a high level		provides the section number of this document that gives a high-level
	description of the feature. The third column provides the section		description of the feature. The third column provides the section
	number of this document that gives a normative description relating		number of this document that gives a normative description relating
	to the feature, when applicable.		to the feature, when applicable.
	+======================+=============+==============================+		+=======================+=============+======================+
	| Feature | High-level | Related normative |		| Feature | High-Level | Related Normative |
	| | description | description |		| | Description | Description |
	+======================+=============+==============================+		+=======================+=============+======================+
	| Entity | Section 3.1 | Section 5.1.3 |		| Entity | Section 3.1 | Section 5.1.3 |
	+----------------------+-------------+------------------------------+		+-----------------------+-------------+----------------------+
	| Entity domain | Section 3.2 | |		| Entity domain | Section 3.2 | |
	| (ED) | | |		+-----------------------+-------------+----------------------+
	+----------------------+-------------+------------------------------+		| Entity domain type | Section | Section 5.1.1 |
	| Entity domain | Section | Section 5.1.1 |		| | 3.2.1 | |
	| type | 3.2.1 | |		+-----------------------+-------------+----------------------+
	+----------------------+-------------+------------------------------+		| Entity domain name | Section | Section 5.1.2 |
	| Entity domain | Section | Section 5.1.2 |		| | 3.2.2 | |
	| name | 3.2.2 | |		+-----------------------+-------------+----------------------+
	+----------------------+-------------+------------------------------+		| Entity property type | Section 3.3 | Sections 5.2, 5.2.1, |
	| Entity property | Section 3.3 | Section 5.2, Section 5.2.1, |		| | | 5.2.2, and 5.2.3 |
	| (EP) type | | Section 5.2.2, Section 5.2.3 |		+-----------------------+-------------+----------------------+
	+----------------------+-------------+------------------------------+		| Entity property map | Section 3.4 | Sections 7 and 8 |
	| Entity property | Section 3.4 | Section 7, Section 8 |		+-----------------------+-------------+----------------------+
	| map | | |		| Resource-specific | Section 4.2 | Sections 5.1.2 and |
	+----------------------+-------------+------------------------------+		| entity domain name | | 5.1.2.1 |
	| Resource-specific | Section 4.2 | Section 5.1.2, |		+-----------------------+-------------+----------------------+
	| ED name | | Section 5.1.2.1 |		| Resource-specific | Section 4.3 | Section 5.2.3 |
	+----------------------+-------------+------------------------------+		| entity property value | | |
	| Resource-specific | Section 4.3 | Section 5.2.3 |		+-----------------------+-------------+----------------------+
	| EP value | | |		| Entity Hierarchy and | Section 4.4 | Section 5.1.4 |
	+----------------------+-------------+------------------------------+		| property inheritance | | |
	| Entity Hierarchy | Section 4.4 | Section 5.1.4 |		+-----------------------+-------------+----------------------+
	| and property | | |		| Defining information | Sections | Sections 12.3.2 and |
	| inheritance | | |		| resource | 4.6 and 4.7 | 12.4 |
	+----------------------+-------------+------------------------------+		+-----------------------+-------------+----------------------+
	| Defining | Section | Section 12.3.2, Section 12.4 |
	| information | 4.6, | |
	| resource | Section 4.7 | |
	+----------------------+-------------+------------------------------+
	Table 4: Features introduced with ALTO Entity Property Maps		Table 11: Features Introduced with ALTO Entity Property Maps
			Acknowledgments
			The authors would like to thank Dawn Chen and Shenshen Chen for their
			contributions to earlier drafts. Thank you also to Qiao Xiang, Shawn
			Lin, and Xin Wang for fruitful discussions. Last, big thanks to
			Danny Perez and Luis Contreras for their substantial working group
			review feedback and suggestions for improving this document, to Vijay
			Gurbani, ALTO WG Chair, and Martin Duke, Transport Area Director, for
			their thorough review, discussions, guidance, and shepherding, which
			further helped to enrich this document.
	Authors' Addresses		Authors' Addresses
	Wendy Roome		Wendy Roome
	Nokia Bell Labs (Retired)		Nokia Bell Labs (Retired)
	124 Burlington Rd		124 Burlington Rd
	Murray Hill, NJ 07974		Murray Hill, NJ 07974
	United States of America		United States of America
	Phone: +1-908-464-6975		Phone: +1-908-464-6975
	Email: wendy@wdroome.com		Email: wendy@wdroome.com
	skipping to change at page 63, line 4 ¶		skipping to change at line 2895 ¶
	Authors' Addresses		Authors' Addresses
	Wendy Roome		Wendy Roome
	Nokia Bell Labs (Retired)		Nokia Bell Labs (Retired)
	124 Burlington Rd		124 Burlington Rd
	Murray Hill, NJ 07974		Murray Hill, NJ 07974
	United States of America		United States of America
	Phone: +1-908-464-6975		Phone: +1-908-464-6975
	Email: wendy@wdroome.com		Email: wendy@wdroome.com
	Sabine Randriamasy		Sabine Randriamasy
	Nokia Bell Labs		Nokia Bell Labs
	Route de Villejust		Route de Villejust
	91460 NOZAY		91460 NOZAY
	France		France
	Email: Sabine.Randriamasy@nokia-bell-labs.com		Email: Sabine.Randriamasy@nokia-bell-labs.com
	Y. Richard Yang		Y. Richard Yang
	Yale University		Yale University
	51 Prospect Street		51 Prospect Street
	New Haven, CT 06511		New Haven, CT 06511
	United States of America		United States of America
	Phone: +1-203-432-6400		Phone: +1-203-432-6400
	Email: yry@cs.yale.edu		Email: yry@cs.yale.edu
	Jingxuan Jensen Zhang		Jingxuan Jensen Zhang
	Tongji University		Tongji University
	4800 Cao'An Hwy		4800 Cao'An Hwy
	Shanghai		Shanghai
	201804		201804
	China		China
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