rfc9297.original   rfc9297.txt 
MASQUE D. Schinazi Internet Engineering Task Force (IETF) D. Schinazi
Internet-Draft Google LLC Request for Comments: 9297 Google LLC
Intended status: Standards Track L. Pardue Category: Standards Track L. Pardue
Expires: 19 December 2022 Cloudflare ISSN: 2070-1721 Cloudflare
17 June 2022 August 2022
HTTP Datagrams and the Capsule Protocol HTTP Datagrams and the Capsule Protocol
draft-ietf-masque-h3-datagram-11
Abstract Abstract
This document describes HTTP Datagrams, a convention for conveying This document describes HTTP Datagrams, a convention for conveying
multiplexed, potentially unreliable datagrams inside an HTTP multiplexed, potentially unreliable datagrams inside an HTTP
connection. connection.
In HTTP/3, HTTP Datagrams can be sent unreliably using the QUIC In HTTP/3, HTTP Datagrams can be sent unreliably using the QUIC
DATAGRAM extension. When the QUIC DATAGRAM frame is unavailable or DATAGRAM extension. When the QUIC DATAGRAM frame is unavailable or
undesirable, they can be sent using the Capsule Protocol, a more undesirable, HTTP Datagrams can be sent using the Capsule Protocol,
general convention for conveying data in HTTP connections. which is a more general convention for conveying data in HTTP
connections.
HTTP Datagrams and the Capsule Protocol are intended for use by HTTP HTTP Datagrams and the Capsule Protocol are intended for use by HTTP
extensions, not applications. extensions, not applications.
About This Document
This note is to be removed before publishing as an RFC.
The latest revision of this draft can be found at https://ietf-wg-
masque.github.io/draft-ietf-masque-h3-datagram/draft-ietf-masque-
h3-datagram.html. Status information for this document may be found
at https://datatracker.ietf.org/doc/draft-ietf-masque-h3-datagram/.
Discussion of this document takes place on the MASQUE Working Group
mailing list (mailto:masque@ietf.org), which is archived at
https://mailarchive.ietf.org/arch/browse/masque/.
Source for this draft and an issue tracker can be found at
https://github.com/ietf-wg-masque/draft-ietf-masque-h3-datagram.
Status of This Memo Status of This Memo
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction
1.1. Conventions and Definitions . . . . . . . . . . . . . . . 3 1.1. Conventions and Definitions
2. HTTP Datagrams . . . . . . . . . . . . . . . . . . . . . . . 4 2. HTTP Datagrams
2.1. HTTP/3 Datagrams . . . . . . . . . . . . . . . . . . . . 4 2.1. HTTP/3 Datagrams
2.1.1. The SETTINGS_H3_DATAGRAM HTTP/3 Setting . . . . . . . 5 2.1.1. The SETTINGS_H3_DATAGRAM HTTP/3 Setting
2.2. HTTP Datagrams using Capsules . . . . . . . . . . . . . . 6 2.2. HTTP Datagrams Using Capsules
3. Capsules . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3. Capsules
3.1. HTTP Data Streams . . . . . . . . . . . . . . . . . . . . 7 3.1. HTTP Data Streams
3.2. The Capsule Protocol . . . . . . . . . . . . . . . . . . 8 3.2. The Capsule Protocol
3.3. Error Handling . . . . . . . . . . . . . . . . . . . . . 9 3.3. Error Handling
3.4. The Capsule-Protocol Header Field . . . . . . . . . . . . 10 3.4. The Capsule-Protocol Header Field
3.5. The DATAGRAM Capsule . . . . . . . . . . . . . . . . . . 10 3.5. The DATAGRAM Capsule
4. Security Considerations . . . . . . . . . . . . . . . . . . . 12 4. Security Considerations
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 5. IANA Considerations
5.1. HTTP/3 Setting . . . . . . . . . . . . . . . . . . . . . 12 5.1. HTTP/3 Setting
5.2. HTTP/3 Error Code . . . . . . . . . . . . . . . . . . . . 13 5.2. HTTP/3 Error Code
5.3. HTTP Header Field Name . . . . . . . . . . . . . . . . . 13 5.3. HTTP Header Field Name
5.4. Capsule Types . . . . . . . . . . . . . . . . . . . . . . 13 5.4. Capsule Types
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 14 6. References
6.1. Normative References . . . . . . . . . . . . . . . . . . 14 6.1. Normative References
6.2. Informative References . . . . . . . . . . . . . . . . . 15 6.2. Informative References
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 16 Acknowledgments
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 16 Authors' Addresses
1. Introduction 1. Introduction
HTTP extensions (as defined in Section 16 of [HTTP]) sometimes need HTTP extensions (as defined in Section 16 of [HTTP]) sometimes need
to access underlying transport protocol features such as unreliable to access underlying transport protocol features such as unreliable
delivery (as offered by [DGRAM]) to enable desirable features. For delivery (as offered by [QUIC-DGRAM]) to enable desirable features.
example, this could allow introducing an unreliable version of the For example, this could allow for the introduction of an unreliable
CONNECT method, or adding unreliable delivery to WebSockets version of the CONNECT method and the addition of unreliable delivery
[WEBSOCKET]. to WebSockets [WEBSOCKET].
In Section 2, this document describes HTTP Datagrams, a convention In Section 2, this document describes HTTP Datagrams, a convention
that supports the bidirectional and optionally multiplexed exchange for conveying bidirectional and potentially unreliable datagrams
of data inside an HTTP connection. While HTTP Datagrams are inside an HTTP connection, with multiplexing when possible. While
associated with HTTP requests, they are not part of message content; HTTP Datagrams are associated with HTTP requests, they are not a part
instead, they are intended for use by HTTP extensions (such as the of message content. Instead, they are intended for use by HTTP
CONNECT method), and are compatible with all versions of HTTP. extensions (such as the CONNECT method) and are compatible with all
versions of HTTP.
When HTTP is running over a transport protocol that supports When HTTP is running over a transport protocol that supports
unreliable delivery (such as when the QUIC DATAGRAM extension [DGRAM] unreliable delivery (such as when the QUIC DATAGRAM extension
is available to HTTP/3 [HTTP/3]), HTTP Datagrams can use that [QUIC-DGRAM] is available to HTTP/3 [HTTP/3]), HTTP Datagrams can use
capability. that capability.
This document also describes the HTTP Capsule Protocol in Section 3, In Section 3, this document describes the HTTP Capsule Protocol,
to allow conveyance of HTTP Datagrams using reliable delivery. This which allows the conveyance of HTTP Datagrams using reliable
addresses HTTP/3 cases where use of the QUIC DATAGRAM frame is delivery. This addresses HTTP/3 cases where use of the QUIC DATAGRAM
unavailable or undesirable, or where the transport protocol only frame is unavailable or undesirable or where the transport protocol
provides reliable delivery, such as with HTTP/1.1 [HTTP/1.1] or only provides reliable delivery, such as with HTTP/1.1 [HTTP/1.1] or
HTTP/2 [HTTP/2] over TCP [TCP]. HTTP/2 [HTTP/2] over TCP [TCP].
1.1. Conventions and Definitions 1.1. Conventions and Definitions
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 "OPTIONAL" in this document are to be interpreted as described in
BCP 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. capitals, as shown here.
skipping to change at page 4, line 11 skipping to change at line 131
types are integers, they are encoded using the variable-length types are integers, they are encoded using the variable-length
integer encoding from Section 16 of [QUIC]. Integer values do not integer encoding from Section 16 of [QUIC]. Integer values do not
need to be encoded on the minimum number of bytes necessary. need to be encoded on the minimum number of bytes necessary.
In this document, the term "intermediary" refers to an HTTP In this document, the term "intermediary" refers to an HTTP
intermediary as defined in Section 3.7 of [HTTP]. intermediary as defined in Section 3.7 of [HTTP].
2. HTTP Datagrams 2. HTTP Datagrams
HTTP Datagrams are a convention for conveying bidirectional and HTTP Datagrams are a convention for conveying bidirectional and
potentially unreliable datagrams inside an HTTP connection, with potentially unreliable datagrams inside an HTTP connection with
multiplexing when possible. All HTTP Datagrams are associated with multiplexing when possible. All HTTP Datagrams are associated with
an HTTP request. an HTTP request.
When HTTP Datagrams are conveyed on an HTTP/3 connection, the QUIC When HTTP Datagrams are conveyed on an HTTP/3 connection, the QUIC
DATAGRAM frame can be used to achieve these goals, including DATAGRAM frame can be used to provide demultiplexing and unreliable
unreliable delivery; see Section 2.1. Negotiating the use of QUIC delivery; see Section 2.1. Negotiating the use of QUIC DATAGRAM
DATAGRAM frames for HTTP Datagrams is achieved via the exchange of frames for HTTP Datagrams is achieved via the exchange of HTTP/3
HTTP/3 settings; see Section 2.1.1. settings; see Section 2.1.1.
When running over HTTP/2, demultiplexing is provided by the HTTP/2 When running over HTTP/2, demultiplexing is provided by the HTTP/2
framing layer, but unreliable delivery is unavailable. HTTP framing layer, but unreliable delivery is unavailable. HTTP
Datagrams are negotiated and conveyed using the Capsule Protocol; see Datagrams are negotiated and conveyed using the Capsule Protocol; see
Section 3.5. Section 3.5.
When running over HTTP/1.x, requests are strictly serialized in the When running over HTTP/1.x, requests are strictly serialized in the
connection, and therefore demultiplexing is not available. connection; therefore, demultiplexing is not available. Unreliable
Unreliable delivery is likewise not available. HTTP Datagrams are delivery is likewise not available. HTTP Datagrams are negotiated
negotiated and conveyed using the Capsule Protocol; see Section 3.5. and conveyed using the Capsule Protocol; see Section 3.5.
HTTP Datagrams MUST only be sent with an association to an HTTP HTTP Datagrams MUST only be sent with an association to an HTTP
request that explicitly supports them. For example, existing HTTP request that explicitly supports them. For example, existing HTTP
methods GET and POST do not define semantics for associated HTTP methods GET and POST do not define semantics for associated HTTP
Datagrams; therefore, HTTP Datagrams cannot be sent associated with Datagrams; therefore, HTTP Datagrams associated with GET or POST
GET or POST request streams. request streams cannot be sent.
If an HTTP Datagram is received and it is associated with a request If an HTTP Datagram is received and it is associated with a request
that has no known semantics for HTTP Datagrams, the receiver MUST that has no known semantics for HTTP Datagrams, the receiver MUST
terminate the request; if HTTP/3 is in use, the request stream MUST terminate the request. If HTTP/3 is in use, the request stream MUST
be aborted with H3_DATAGRAM_ERROR (0x33). HTTP extensions MAY be aborted with H3_DATAGRAM_ERROR (0x33). HTTP extensions MAY
override these requirements by defining a negotiation mechanism and override these requirements by defining a negotiation mechanism and
semantics for HTTP Datagrams. semantics for HTTP Datagrams.
2.1. HTTP/3 Datagrams 2.1. HTTP/3 Datagrams
When used with HTTP/3, the Datagram Data field of QUIC DATAGRAM When used with HTTP/3, the Datagram Data field of QUIC DATAGRAM
frames uses the following format: frames uses the following format:
HTTP/3 Datagram { HTTP/3 Datagram {
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2.1. HTTP/3 Datagrams 2.1. HTTP/3 Datagrams
When used with HTTP/3, the Datagram Data field of QUIC DATAGRAM When used with HTTP/3, the Datagram Data field of QUIC DATAGRAM
frames uses the following format: frames uses the following format:
HTTP/3 Datagram { HTTP/3 Datagram {
Quarter Stream ID (i), Quarter Stream ID (i),
HTTP Datagram Payload (..), HTTP Datagram Payload (..),
} }
Figure 1: HTTP/3 Datagram Format Figure 1: HTTP/3 Datagram Format
Quarter Stream ID: A variable-length integer that contains the value Quarter Stream ID: A variable-length integer that contains the value
of the client-initiated bidirectional stream that this datagram is of the client-initiated bidirectional stream that this datagram is
associated with, divided by four (the division by four stems from associated with divided by four (the division by four stems from
the fact that HTTP requests are sent on client-initiated the fact that HTTP requests are sent on client-initiated
bidirectional streams, and those have stream IDs that are bidirectional streams, which have stream IDs that are divisible by
divisible by four). The largest legal QUIC stream ID value is four). The largest legal QUIC stream ID value is 2^62-1, so the
2^62-1, so the largest legal value of Quarter Stream ID is 2^60-1. largest legal value of the Quarter Stream ID field is 2^60-1.
Receipt of an HTTP/3 Datagram that includes a larger value MUST be Receipt of an HTTP/3 Datagram that includes a larger value MUST be
treated as an HTTP/3 connection error of type H3_DATAGRAM_ERROR treated as an HTTP/3 connection error of type H3_DATAGRAM_ERROR
(0x33). (0x33).
HTTP Datagram Payload: The payload of the datagram, whose semantics HTTP Datagram Payload: The payload of the datagram, whose semantics
are defined by the extension that is using HTTP Datagrams. Note are defined by the extension that is using HTTP Datagrams. Note
that this field can be empty. that this field can be empty.
Receipt of a QUIC DATAGRAM frame whose payload is too short to allow Receipt of a QUIC DATAGRAM frame whose payload is too short to allow
parsing the Quarter Stream ID field MUST be treated as an HTTP/3 parsing the Quarter Stream ID field MUST be treated as an HTTP/3
connection error of type H3_DATAGRAM_ERROR (0x33). connection error of type H3_DATAGRAM_ERROR (0x33).
HTTP/3 Datagrams MUST NOT be sent unless the corresponding stream's HTTP/3 Datagrams MUST NOT be sent unless the corresponding stream's
send side is open. If a datagram is received after the corresponding send side is open. If a datagram is received after the corresponding
stream's receive side is closed, the received datagrams MUST be stream's receive side is closed, the received datagrams MUST be
silently dropped. silently dropped.
If an HTTP/3 Datagram is received and its Quarter Stream ID maps to a If an HTTP/3 Datagram is received and its Quarter Stream ID field
stream that has not yet been created, the receiver SHALL either drop maps to a stream that has not yet been created, the receiver SHALL
that datagram silently or buffer it temporarily (on the order of a either drop that datagram silently or buffer it temporarily (on the
round trip) while awaiting the creation of the corresponding stream. order of a round trip) while awaiting the creation of the
corresponding stream.
If an HTTP/3 Datagram is received and its Quarter Stream ID maps to a If an HTTP/3 Datagram is received and its Quarter Stream ID field
stream that cannot be created due to client-initiated bidirectional maps to a stream that cannot be created due to client-initiated
stream limits, it SHOULD be treated as an HTTP/3 connection error of bidirectional stream limits, it SHOULD be treated as an HTTP/3
type H3_ID_ERROR. Generating an error is not mandatory in this case connection error of type H3_ID_ERROR. Generating an error is not
because HTTP/3 implementations might have practical barriers to mandatory because the QUIC stream limit might be unknown to the
determining the active stream concurrency limit that is applied by HTTP/3 layer.
the QUIC layer.
Prioritization of HTTP/3 Datagrams is not defined in this document. Prioritization of HTTP/3 Datagrams is not defined in this document.
Future extensions MAY define how to prioritize datagrams, and MAY Future extensions MAY define how to prioritize datagrams and MAY
define signaling to allow communicating prioritization preferences. define signaling to allow communicating prioritization preferences.
2.1.1. The SETTINGS_H3_DATAGRAM HTTP/3 Setting 2.1.1. The SETTINGS_H3_DATAGRAM HTTP/3 Setting
Endpoints can indicate to their peer that they are willing to receive An endpoint can indicate to its peer that it is willing to receive
HTTP/3 Datagrams by sending the SETTINGS_H3_DATAGRAM (0x33) setting HTTP/3 Datagrams by sending the SETTINGS_H3_DATAGRAM (0x33) setting
with a value of 1. with a value of 1.
The value of the SETTINGS_H3_DATAGRAM setting MUST be either 0 or 1. The value of the SETTINGS_H3_DATAGRAM setting MUST be either 0 or 1.
A value of 0 indicates that the implementation is not willing to A value of 0 indicates that the implementation is not willing to
receive HTTP Datagrams. If the SETTINGS_H3_DATAGRAM setting is receive HTTP Datagrams. If the SETTINGS_H3_DATAGRAM setting is
received with a value that is neither 0 nor 1, the receiver MUST received with a value that is neither 0 nor 1, the receiver MUST
terminate the connection with error H3_SETTINGS_ERROR. terminate the connection with error H3_SETTINGS_ERROR.
QUIC DATAGRAM frames MUST NOT be sent until the SETTINGS_H3_DATAGRAM QUIC DATAGRAM frames MUST NOT be sent until the SETTINGS_H3_DATAGRAM
skipping to change at page 6, line 33 skipping to change at line 251
greater than or equal to the stored value; if not, the client MUST greater than or equal to the stored value; if not, the client MUST
terminate the connection with error H3_SETTINGS_ERROR. In all cases, terminate the connection with error H3_SETTINGS_ERROR. In all cases,
the maximum permitted value of the SETTINGS_H3_DATAGRAM setting the maximum permitted value of the SETTINGS_H3_DATAGRAM setting
parameter is 1. parameter is 1.
It is RECOMMENDED that implementations that support receiving HTTP/3 It is RECOMMENDED that implementations that support receiving HTTP/3
Datagrams always send the SETTINGS_H3_DATAGRAM setting with a value Datagrams always send the SETTINGS_H3_DATAGRAM setting with a value
of 1, even if the application does not intend to use HTTP/3 of 1, even if the application does not intend to use HTTP/3
Datagrams. This helps to avoid "sticking out"; see Section 4. Datagrams. This helps to avoid "sticking out"; see Section 4.
2.1.1.1. Note About Draft Versions 2.2. HTTP Datagrams Using Capsules
[[RFC editor: please remove this section before publication.]]
Some revisions of this draft specification use a different value (the
Identifier field of a Setting in the HTTP/3 SETTINGS frame) for the
SETTINGS_H3_DATAGRAM setting. This allows new draft revisions to
make incompatible changes. Multiple draft versions MAY be supported
by sending multiple values for SETTINGS_H3_DATAGRAM. Once SETTINGS
have been sent and received, an implementation that supports multiple
drafts MUST compute the intersection of the values it has sent and
received, and then it MUST select and use the most recent draft
version from the intersection set. This ensures that both peers
negotiate the same draft version.
2.2. HTTP Datagrams using Capsules
When HTTP/3 Datagrams are unavailable or undesirable, HTTP Datagrams When HTTP/3 Datagrams are unavailable or undesirable, HTTP Datagrams
can be sent using the Capsule Protocol, see Section 3.5. can be sent using the Capsule Protocol; see Section 3.5.
3. Capsules 3. Capsules
One mechanism to extend HTTP is to introduce new HTTP Upgrade Tokens One mechanism to extend HTTP is to introduce new HTTP upgrade tokens;
(see Section 16.7 of [HTTP]). In HTTP/1.x, these tokens are used via see Section 16.7 of [HTTP]. In HTTP/1.x, these tokens are used via
the Upgrade mechanism (see Section 7.8 of [HTTP]). In HTTP/2 and the Upgrade mechanism; see Section 7.8 of [HTTP]. In HTTP/2 and
HTTP/3, these tokens are used via the Extended CONNECT mechanism (see HTTP/3, these tokens are used via the Extended CONNECT mechanism; see
[EXT-CONNECT2] and [EXT-CONNECT3]). [EXT-CONNECT2] and [EXT-CONNECT3].
This specification introduces the Capsule Protocol. The Capsule This specification introduces the Capsule Protocol. The Capsule
Protocol is a sequence of type-length-value tuples that definitions Protocol is a sequence of type-length-value tuples that definitions
of new HTTP Upgrade Tokens can choose to use. It allows endpoints to of new HTTP upgrade tokens can choose to use. It allows endpoints to
reliably communicate request-related information end-to-end on HTTP reliably communicate request-related information end-to-end on HTTP
request streams, even in the presence of HTTP intermediaries. The request streams, even in the presence of HTTP intermediaries. The
Capsule Protocol can be used to exchange HTTP Datagrams, which is Capsule Protocol can be used to exchange HTTP Datagrams, which is
necessary when HTTP is running over a transport that does not support necessary when HTTP is running over a transport that does not support
the QUIC DATAGRAM frame. The Capsule Protocol can also be used to the QUIC DATAGRAM frame. The Capsule Protocol can also be used to
communicate reliable and bidirectional control messages associated communicate reliable and bidirectional control messages associated
with a datagram-based protocol even when HTTP/3 Datagrams are in use. with a datagram-based protocol even when HTTP/3 Datagrams are in use.
3.1. HTTP Data Streams 3.1. HTTP Data Streams
This specification defines the "data stream" of an HTTP request as This specification defines the "data stream" of an HTTP request as
the bidirectional stream of bytes that follows the header section of the bidirectional stream of bytes that follows the header section of
the request message and the final response message that is either the request message and the final response message that is either
successful (i.e., 2xx) or upgraded (i.e., 101). successful (i.e., 2xx) or upgraded (i.e., 101).
In HTTP/1.x, the data stream consists of all bytes on the connection In HTTP/1.x, the data stream consists of all bytes on the connection
that follow the blank line that concludes either the request header that follow the blank line that concludes either the request header
section, or the final response header section. As a result, only the section or the final response header section. As a result, only the
last HTTP request on an HTTP/1.x connection can start the capsule last HTTP request on an HTTP/1.x connection can start the Capsule
protocol. Protocol.
In HTTP/2 and HTTP/3, the data stream of a given HTTP request In HTTP/2 and HTTP/3, the data stream of a given HTTP request
consists of all bytes sent in DATA frames with the corresponding consists of all bytes sent in DATA frames with the corresponding
stream ID. stream ID.
The concept of a data stream is particularly relevant for methods The concept of a data stream is particularly relevant for methods
such as CONNECT where there is no HTTP message content after the such as CONNECT, where there is no HTTP message content after the
headers. headers.
Data streams can be prioritized using any means suited to stream or Data streams can be prioritized using any means suited to stream or
request prioritization. For example, see Section 11 of [PRIORITY]. request prioritization. For example, see Section 11 of [PRIORITY].
Data streams are subject to the flow control mechanisms of the Data streams are subject to the flow control mechanisms of the
underlying layers (for example, HTTP/2 stream flow control, HTTP/2 underlying layers; examples include HTTP/2 stream flow control,
connection flow control, and TCP flow control). HTTP/2 connection flow control, and TCP flow control.
3.2. The Capsule Protocol 3.2. The Capsule Protocol
Definitions of new HTTP Upgrade Tokens can state that their Definitions of new HTTP upgrade tokens can state that their
associated request's data stream uses the Capsule Protocol. If they associated request's data stream uses the Capsule Protocol. If they
do so, that means that the contents of the associated request's data do so, the contents of the associated request's data stream uses the
stream uses the following format: following format:
Capsule Protocol { Capsule Protocol {
Capsule (..) ..., Capsule (..) ...,
} }
Figure 2: Capsule Protocol Stream Format Figure 2: Capsule Protocol Stream Format
Capsule { Capsule {
Capsule Type (i), Capsule Type (i),
Capsule Length (i), Capsule Length (i),
Capsule Value (..), Capsule Value (..),
} }
Figure 3: Capsule Format Figure 3: Capsule Format
Capsule Type: A variable-length integer indicating the Type of the Capsule Type: A variable-length integer indicating the type of the
capsule. An IANA registry is used to manage the assignment of capsule. An IANA registry is used to manage the assignment of
Capsule Types; see Section 5.4. Capsule Types; see Section 5.4.
Capsule Length: The length in bytes of the Capsule Value field Capsule Length: The length, in bytes, of the Capsule Value field,
following this field, encoded as a variable-length integer. Note which follows this field, encoded as a variable-length integer.
that this field can have a value of zero. Note that this field can have a value of zero.
Capsule Value: The payload of this capsule. Its semantics are Capsule Value: The payload of this Capsule. Its semantics are
determined by the value of the Capsule Type field. determined by the value of the Capsule Type field.
An intermediary can identify the use of the capsule protocol either An intermediary can identify the use of the Capsule Protocol either
through the presence of the Capsule-Protocol header field through the presence of the Capsule-Protocol header field
(Section 3.4) or by understanding the chosen HTTP Upgrade token. (Section 3.4) or by understanding the chosen HTTP Upgrade token.
Because new protocols or extensions might define new capsule types, Because new protocols or extensions might define new Capsule Types,
intermediaries that wish to allow for future extensibility SHOULD intermediaries that wish to allow for future extensibility SHOULD
forward capsules without modification, unless the definition of the forward Capsules without modification unless the definition of the
Capsule Type in use specifies additional intermediary processing. Capsule Type in use specifies additional intermediary processing.
One such Capsule Type is the DATAGRAM capsule; see Section 3.5. In One such Capsule Type is the DATAGRAM Capsule; see Section 3.5. In
particular, intermediaries SHOULD forward Capsules with an unknown particular, intermediaries SHOULD forward Capsules with an unknown
Capsule Type without modification. Capsule Type without modification.
Endpoints which receive a Capsule with an unknown Capsule Type MUST Endpoints that receive a Capsule with an unknown Capsule Type MUST
silently drop that Capsule and skip over it to parse the next silently drop that Capsule and skip over it to parse the next
Capsule. Capsule.
By virtue of the definition of the data stream: By virtue of the definition of the data stream:
* The Capsule Protocol is not in use unless the response includes a * The Capsule Protocol is not in use unless the response includes a
2xx (Successful) or 101 (Switching Protocols) status code. 2xx (Successful) or 101 (Switching Protocols) status code.
* When the Capsule Protocol is in use, the associated HTTP request * When the Capsule Protocol is in use, the associated HTTP request
and response do not carry HTTP content. A future extension MAY and response do not carry HTTP content. A future extension MAY
define a new capsule type to carry HTTP content. define a new Capsule Type to carry HTTP content.
Since the Capsule Protocol only applies to definitions of new HTTP The Capsule Protocol only applies to definitions of new HTTP upgrade
Upgrade Tokens, in HTTP/2 and HTTP/3 it can only be used with the tokens; thus, in HTTP/2 and HTTP/3, it can only be used with the
CONNECT method. Therefore, once both endpoints agree to use the CONNECT method. Therefore, once both endpoints agree to use the
Capsule Protocol, the frame usage requirements of the stream change Capsule Protocol, the frame usage requirements of the stream change
as specified in Section 8.5 of [HTTP/2] and Section 4.2 of [HTTP/3]. as specified in Section 8.5 of [HTTP/2] and Section 4.4 of [HTTP/3].
The Capsule Protocol MUST NOT be used with messages that contain The Capsule Protocol MUST NOT be used with messages that contain
Content-Length, Content-Type, or Transfer-Encoding header fields. Content-Length, Content-Type, or Transfer-Encoding header fields.
Additionally, HTTP status codes 204 (No Content), 205 (Reset Additionally, HTTP status codes 204 (No Content), 205 (Reset
Content), and 206 (Partial Content) MUST NOT be sent on responses Content), and 206 (Partial Content) MUST NOT be sent on responses
that use the Capsule Protocol. A receiver that observes a violation that use the Capsule Protocol. A receiver that observes a violation
of these requirements MUST treat the HTTP message as malformed. of these requirements MUST treat the HTTP message as malformed.
When processing capsules, a receiver might be tempted to accumulate When processing Capsules, a receiver might be tempted to accumulate
the full length of the capsule value in the data stream before the full length of the Capsule Value field in the data stream before
handling it. This approach SHOULD be avoided, because it can consume handling it. This approach SHOULD be avoided because it can consume
flow control in underlying layers, and that might lead to deadlocks flow control in underlying layers, and that might lead to deadlocks
if the capsule data exhausts the flow control window. if the Capsule data exhausts the flow control window.
3.3. Error Handling 3.3. Error Handling
When a receiver encounters an error processing the Capsule Protocol, When a receiver encounters an error processing the Capsule Protocol,
the receiver MUST treat it as if it had received a malformed or the receiver MUST treat it as if it had received a malformed or
incomplete HTTP message. For HTTP/3, the handling of malformed incomplete HTTP message. For HTTP/3, the handling of malformed
messages is described in Section 4.1.3 of [HTTP/3]. For HTTP/2, the messages is described in Section 4.1.2 of [HTTP/3]. For HTTP/2, the
handling of malformed messages is described in Section 8.1.1 of handling of malformed messages is described in Section 8.1.1 of
[HTTP/2]. For HTTP/1.x, the handling of incomplete messages is [HTTP/2]. For HTTP/1.x, the handling of incomplete messages is
described in Section 8 of [HTTP/1.1]. described in Section 8 of [HTTP/1.1].
Each capsule's payload MUST contain exactly the fields identified in Each Capsule's payload MUST contain exactly the fields identified in
its description. A capsule payload that contains additional bytes its description. A Capsule payload that contains additional bytes
after the identified fields or a capsule payload that terminates after the identified fields or a Capsule payload that terminates
before the end of the identified fields MUST be treated as it if were before the end of the identified fields MUST be treated as it if were
a malformed or incomplete message. In particular, redundant length a malformed or incomplete message. In particular, redundant length
encodings MUST be verified to be self-consistent. encodings MUST be verified to be self-consistent.
If the receive side of a stream carrying capsules is terminated If the receive side of a stream carrying Capsules is terminated
cleanly (for example, in HTTP/3 this is defined as receiving a QUIC cleanly (for example, in HTTP/3 this is defined as receiving a QUIC
STREAM frame with the FIN bit set) and the last capsule on the stream STREAM frame with the FIN bit set) and the last Capsule on the stream
was truncated, this MUST be treated as if it were a malformed or was truncated, this MUST be treated as if it were a malformed or
incomplete message. incomplete message.
3.4. The Capsule-Protocol Header Field 3.4. The Capsule-Protocol Header Field
The "Capsule-Protocol" header field is an Item Structured Field, see The "Capsule-Protocol" header field is an Item Structured Field; see
Section 3.3 of [STRUCT-FIELD]; its value MUST be a Boolean; any other Section 3.3 of [STRUCTURED-FIELDS]. Its value MUST be a Boolean; any
value type MUST be handled as if the field were not present by other value type MUST be handled as if the field were not present by
recipients (for example, if this field is included multiple times, recipients (for example, if this field is included multiple times,
its type will become a List and the field will therefore be ignored). its type will become a List and the field will be ignored). This
This document does not define any parameters for the Capsule-Protocol document does not define any parameters for the Capsule-Protocol
header field value, but future documents might define parameters. header field value, but future documents might define parameters.
Receivers MUST ignore unknown parameters. Receivers MUST ignore unknown parameters.
Endpoints indicate that the Capsule Protocol is in use on a data Endpoints indicate that the Capsule Protocol is in use on a data
stream by sending a Capsule-Protocol header field with a true value. stream by sending a Capsule-Protocol header field with a true value.
A Capsule-Protocol header field with a false value has the same A Capsule-Protocol header field with a false value has the same
semantics as when the header is not present. semantics as when the header is not present.
Intermediaries MAY use this header field to allow processing of HTTP Intermediaries MAY use this header field to allow processing of HTTP
Datagrams for unknown HTTP Upgrade Tokens; note that this is only Datagrams for unknown HTTP upgrade tokens. Note that this is only
possible for HTTP Upgrade or Extended CONNECT. possible for HTTP Upgrade or Extended CONNECT.
The Capsule-Protocol header field MUST NOT be used on HTTP responses The Capsule-Protocol header field MUST NOT be used on HTTP responses
with a status code that is both different from 101 and outside the with a status code that is both different from 101 (Switching
2xx range. Protocols) and outside the 2xx (Successful) range.
When using the Capsule Protocol, HTTP endpoints SHOULD send the When using the Capsule Protocol, HTTP endpoints SHOULD send the
Capsule-Protocol header field to simplify intermediary processing. Capsule-Protocol header field to simplify intermediary processing.
Definitions of new HTTP Upgrade Tokens that use the Capsule Protocol Definitions of new HTTP upgrade tokens that use the Capsule Protocol
MAY alter this recommendation. MAY alter this recommendation.
3.5. The DATAGRAM Capsule 3.5. The DATAGRAM Capsule
This document defines the DATAGRAM (0x00) capsule type. This capsule This document defines the DATAGRAM (0x00) Capsule Type. This Capsule
allows HTTP Datagrams to be sent on a stream using the Capsule allows HTTP Datagrams to be sent on a stream using the Capsule
Protocol. This is particularly useful when HTTP is running over a Protocol. This is particularly useful when HTTP is running over a
transport that does not support the QUIC DATAGRAM frame. transport that does not support the QUIC DATAGRAM frame.
Datagram Capsule { Datagram Capsule {
Type (i) = 0x00, Type (i) = 0x00,
Length (i), Length (i),
HTTP Datagram Payload (..), HTTP Datagram Payload (..),
} }
Figure 4: DATAGRAM Capsule Format Figure 4: DATAGRAM Capsule Format
HTTP Datagram Payload: The payload of the datagram, whose semantics HTTP Datagram Payload: The payload of the datagram, whose semantics
are defined by the extension that is using HTTP Datagrams. Note are defined by the extension that is using HTTP Datagrams. Note
that this field can be empty. that this field can be empty.
HTTP Datagrams sent using the DATAGRAM capsule have the same HTTP Datagrams sent using the DATAGRAM Capsule have the same
semantics as those sent in QUIC DATAGRAM frames. In particular, the semantics as those sent in QUIC DATAGRAM frames. In particular, the
restrictions on when it is allowed to send an HTTP Datagram and how restrictions on when it is allowed to send an HTTP Datagram and how
to process them from Section 2.1 also apply to HTTP Datagrams sent to process them (from Section 2.1) also apply to HTTP Datagrams sent
and received using the DATAGRAM capsule. and received using the DATAGRAM Capsule.
An intermediary can reencode HTTP Datagrams as it forwards them. In An intermediary can re-encode HTTP Datagrams as it forwards them. In
other words, an intermediary MAY send a DATAGRAM capsule to forward other words, an intermediary MAY send a DATAGRAM Capsule to forward
an HTTP Datagram that was received in a QUIC DATAGRAM frame, and vice an HTTP Datagram that was received in a QUIC DATAGRAM frame and vice
versa. Intermediaries MUST NOT perform this reencoding unless they versa. Intermediaries MUST NOT perform this re-encoding unless they
have identified the use of the Capsule Protocol on the corresponding have identified the use of the Capsule Protocol on the corresponding
request stream; see Section 3.2. request stream; see Section 3.2.
Note that while DATAGRAM capsules that are sent on a stream are Note that while DATAGRAM Capsules, which are sent on a stream, are
reliably delivered in order, intermediaries can reencode DATAGRAM reliably delivered in order, intermediaries can re-encode DATAGRAM
capsules into QUIC DATAGRAM frames when forwarding messages, which Capsules into QUIC DATAGRAM frames when forwarding messages, which
could result in loss or reordering. could result in loss or reordering.
If an intermediary receives an HTTP Datagram in a QUIC DATAGRAM frame If an intermediary receives an HTTP Datagram in a QUIC DATAGRAM frame
and is forwarding it on a connection that supports QUIC DATAGRAM and is forwarding it on a connection that supports QUIC DATAGRAM
frames, the intermediary SHOULD NOT convert that HTTP Datagram to a frames, the intermediary SHOULD NOT convert that HTTP Datagram to a
DATAGRAM capsule. If the HTTP Datagram is too large to fit in a DATAGRAM Capsule. If the HTTP Datagram is too large to fit in a
DATAGRAM frame (for example because the path MTU of that QUIC DATAGRAM frame (for example, because the Path MTU (PMTU) of that QUIC
connection is too low or if the maximum UDP payload size advertised connection is too low or if the maximum UDP payload size advertised
on that connection is too low), the intermediary SHOULD drop the HTTP on that connection is too low), the intermediary SHOULD drop the HTTP
Datagram instead of converting it to a DATAGRAM capsule. This Datagram instead of converting it to a DATAGRAM Capsule. This
preserves the end-to-end unreliability characteristic that methods preserves the end-to-end unreliability characteristic that methods
such as Datagram Packetization Layer Path MTU Discovery (DPLPMTUD) such as Datagram Packetization Layer PMTU Discovery (DPLPMTUD) depend
depend on [DPLPMTUD]. An intermediary that converts QUIC DATAGRAM on [DPLPMTUD]. An intermediary that converts QUIC DATAGRAM frames to
frames to DATAGRAM capsules allows HTTP Datagrams to be arbitrarily DATAGRAM Capsules allows HTTP Datagrams to be arbitrarily large
large without suffering any loss; this can misrepresent the true path without suffering any loss. This can misrepresent the true path
properties, defeating methods such as DPLPMTUD. properties, defeating methods such as DPLPMTUD.
While DATAGRAM capsules can theoretically carry a payload of length While DATAGRAM Capsules can theoretically carry a payload of length
2^62-1, most HTTP extensions that use HTTP Datagrams will have their 2^62-1, most HTTP extensions that use HTTP Datagrams will have their
own limits on what datagram payload sizes are practical. own limits on what datagram payload sizes are practical.
Implementations SHOULD take those limits into account when parsing Implementations SHOULD take those limits into account when parsing
DATAGRAM capsules: if an incoming DATAGRAM capsule has a length that DATAGRAM Capsules. If an incoming DATAGRAM Capsule has a length that
is known to be so large as to not be usable, the implementation is known to be so large as to not be usable, the implementation
SHOULD discard the capsule without buffering its contents into SHOULD discard the Capsule without buffering its contents into
memory. memory.
Since QUIC DATAGRAM frames are required to fit within a QUIC packet, Since QUIC DATAGRAM frames are required to fit within a QUIC packet,
implementations that reencode DATAGRAM capsules into QUIC DATAGRAM implementations that re-encode DATAGRAM Capsules into QUIC DATAGRAM
frames might be tempted to accumulate the entire capsule in the frames might be tempted to accumulate the entire Capsule in the
stream before reencoding it. This SHOULD be avoided, because it can stream before re-encoding it. This SHOULD be avoided, because it can
cause flow control problems; see Section 3.2. cause flow control problems; see Section 3.2.
Note that it is possible for an HTTP extension to use HTTP Datagrams Note that it is possible for an HTTP extension to use HTTP Datagrams
without using the Capsule Protocol. For example, if an HTTP without using the Capsule Protocol. For example, if an HTTP
extension that uses HTTP Datagrams is only defined over transports extension that uses HTTP Datagrams is only defined over transports
that support QUIC DATAGRAM frames, it might not need a stream that support QUIC DATAGRAM frames, it might not need a stream
encoding. Additionally, HTTP extensions can use HTTP Datagrams with encoding. Additionally, HTTP extensions can use HTTP Datagrams with
their own data stream protocol. However, new HTTP extensions that their own data stream protocol. However, new HTTP extensions that
wish to use HTTP Datagrams SHOULD use the Capsule Protocol as failing wish to use HTTP Datagrams SHOULD use the Capsule Protocol, as
to do so will make it harder for the HTTP extension to support failing to do so will make it harder for the HTTP extension to
versions of HTTP other than HTTP/3 and will prevent interoperability support versions of HTTP other than HTTP/3 and will prevent
with intermediaries that only support the Capsule Protocol. interoperability with intermediaries that only support the Capsule
Protocol.
4. Security Considerations 4. Security Considerations
Since transmitting HTTP Datagrams using QUIC DATAGRAM frames requires Since transmitting HTTP Datagrams using QUIC DATAGRAM frames requires
sending the HTTP/3 SETTINGS_H3_DATAGRAM setting, it "sticks out". In sending the HTTP/3 SETTINGS_H3_DATAGRAM setting, it "sticks out". In
other words, probing clients can learn whether a server supports HTTP other words, probing clients can learn whether a server supports HTTP
Datagrams over QUIC DATAGRAM frames. As some servers might wish to Datagrams over QUIC DATAGRAM frames. As some servers might wish to
obfuscate the fact that they offer application services that use HTTP obfuscate the fact that they offer application services that use HTTP
Datagrams, it's best for all implementations that support this Datagrams, it's best for all implementations that support this
feature to always send this setting, see Section 2.1.1. feature to always send this setting; see Section 2.1.1.
Since use of the Capsule Protocol is restricted to new HTTP Upgrade Since use of the Capsule Protocol is restricted to new HTTP upgrade
Tokens, it is not accessible from Web Platform APIs (such as those tokens, it is not directly accessible from Web Platform APIs (such as
commonly accessed via JavaScript in web browsers). those commonly accessed via JavaScript in web browsers).
Definitions of new HTTP Upgrade Tokens that use the Capsule Protocol Definitions of new HTTP upgrade tokens that use the Capsule Protocol
need to perform a security analysis that considers the impact of HTTP need to include a security analysis that considers the impact of HTTP
Datagrams and Capsules in the context of their protocol. Datagrams and Capsules in the context of their protocol.
5. IANA Considerations 5. IANA Considerations
5.1. HTTP/3 Setting 5.1. HTTP/3 Setting
This document will request IANA to register the following entry in IANA has registered the following entry in the "HTTP/3 Settings"
the "HTTP/3 Settings" registry maintained at registry maintained at <https://www.iana.org/assignments/
<https://www.iana.org/assignments/http3-parameters>: http3-parameters>:
Value: 0x33 Value: 0x33
Setting Name: SETTINGS_H3_DATAGRAM Setting Name: SETTINGS_H3_DATAGRAM
Default: 0 Default: 0
Status: provisional (permanent if this document is approved) Status: permanent
Specification: This Document Reference: RFC 9297
Change Controller: IETF Change Controller: IETF
Contact: HTTP_WG; HTTP working group; ietf-http-wg@w3.org Contact: HTTP_WG; HTTP working group; ietf-http-wg@w3.org
Notes: None
5.2. HTTP/3 Error Code 5.2. HTTP/3 Error Code
This document will request IANA to register the following entry in IANA has registered the following entry in the "HTTP/3 Error Codes"
the "HTTP/3 Error Codes" registry maintained at registry maintained at <https://www.iana.org/assignments/
<https://www.iana.org/assignments/http3-parameters>: http3-parameters>:
Value: 0x33 Value: 0x33
Name: H3_DATAGRAM_ERROR Name: H3_DATAGRAM_ERROR
Description: Datagram or capsule protocol parse error Description: Datagram or Capsule Protocol parse error
Status: provisional (permanent if this document is approved) Status: permanent
Specification: This Document Reference: RFC 9297
Change Controller: IETF Change Controller: IETF
Contact: HTTP_WG; HTTP working group; ietf-http-wg@w3.org Contact: HTTP_WG; HTTP working group; ietf-http-wg@w3.org
Notes: None
5.3. HTTP Header Field Name 5.3. HTTP Header Field Name
This document will request IANA to register the following entry in IANA has registered the following entry in the "Hypertext Transfer
the "HTTP Field Name" registry maintained at Protocol (HTTP) Field Name Registry" maintained at
<https://www.iana.org/assignments/http-fields>: <https://www.iana.org/assignments/http-fields>:
Field Name: Capsule-Protocol Field Name: Capsule-Protocol
Template: None Template: None
Status: provisional (permanent if this document is approved) Status: permanent
Reference: This document Reference: RFC 9297
Comments: None Comments: None
5.4. Capsule Types 5.4. Capsule Types
This document establishes a registry for HTTP capsule type codes. This document establishes a registry for HTTP Capsule Type codes.
The "HTTP Capsule Types" registry governs a 62-bit space, and The "HTTP Capsule Types" registry governs a 62-bit space and operates
operates under the QUIC registration policy documented in under the QUIC registration policy documented in Section 22.1 of
Section 22.1 of [QUIC]. This new registry includes the common set of [QUIC]. This new registry includes the common set of fields listed
fields listed in Section 22.1.1 of [QUIC]. In addition to those in Section 22.1.1 of [QUIC]. In addition to those common fields, all
common fields, all registrations in this registry MUST include a registrations in this registry MUST include a "Capsule Type" field
"Capsule Type" field which contains a short name or label for the that contains a short name or label for the Capsule Type.
capsule type.
Permanent registrations in this registry are assigned using the Permanent registrations in this registry are assigned using the
Specification Required policy (Section 4.6 of [IANA-POLICY]), except Specification Required policy (Section 4.6 of [IANA-POLICY]), except
for values between 0x00 and 0x3f (in hexadecimal; inclusive), which for values between 0x00 and 0x3f (in hexadecimal; inclusive), which
are assigned using Standards Action or IESG Approval as defined in are assigned using Standards Action or IESG Approval as defined in
Sections 4.9 and 4.10 of [IANA-POLICY]. Sections 4.9 and 4.10 of [IANA-POLICY].
Capsule types with a value of the form 0x29 * N + 0x17 for integer Capsule Types with a value of the form 0x29 * N + 0x17 for integer
values of N are reserved to exercise the requirement that unknown values of N are reserved to exercise the requirement that unknown
capsule types be ignored. These capsules have no semantics and can Capsule Types be ignored. These Capsules have no semantics and can
carry arbitrary values. These values MUST NOT be assigned by IANA carry arbitrary values. These values MUST NOT be assigned by IANA
and MUST NOT appear in the listing of assigned values. and MUST NOT appear in the listing of assigned values.
This registry initially contains the following entry: This registry initially contains the following entry:
Value: 0x00 Value: 0x00
Capsule Type: DATAGRAM Capsule Type: DATAGRAM
Status: permanent Status: permanent
Specification: This document Reference: RFC 9297
Change Controller: IETF Change Controller: IETF
Contact: MASQUE Working Group masque@ietf.org Contact: MASQUE Working Group masque@ietf.org
(mailto:masque@ietf.org) (mailto:masque@ietf.org)
Notes: None Notes: None
6. References 6. References
6.1. Normative References 6.1. Normative References
[DGRAM] Pauly, T., Kinnear, E., and D. Schinazi, "An Unreliable
Datagram Extension to QUIC", RFC 9221,
DOI 10.17487/RFC9221, March 2022,
<https://www.rfc-editor.org/rfc/rfc9221>.
[HTTP] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke, [HTTP] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke,
Ed., "HTTP Semantics", STD 97, RFC 9110, Ed., "HTTP Semantics", STD 97, RFC 9110,
DOI 10.17487/RFC9110, June 2022, DOI 10.17487/RFC9110, June 2022,
<https://www.rfc-editor.org/rfc/rfc9110>. <https://www.rfc-editor.org/info/rfc9110>.
[HTTP/1.1] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke, [HTTP/1.1] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke,
Ed., "HTTP/1.1", STD 99, RFC 9112, DOI 10.17487/RFC9112, Ed., "HTTP/1.1", STD 99, RFC 9112, DOI 10.17487/RFC9112,
June 2022, <https://www.rfc-editor.org/rfc/rfc9112>. June 2022, <https://www.rfc-editor.org/info/rfc9112>.
[HTTP/2] Thomson, M., Ed. and C. Benfield, Ed., "HTTP/2", RFC 9113, [HTTP/2] Thomson, M., Ed. and C. Benfield, Ed., "HTTP/2", RFC 9113,
DOI 10.17487/RFC9113, June 2022, DOI 10.17487/RFC9113, June 2022,
<https://www.rfc-editor.org/rfc/rfc9113>. <https://www.rfc-editor.org/info/rfc9113>.
[HTTP/3] Bishop, M., Ed., "HTTP/3", RFC 9114, DOI 10.17487/RFC9114, [HTTP/3] Bishop, M., Ed., "HTTP/3", RFC 9114, DOI 10.17487/RFC9114,
June 2022, <https://www.rfc-editor.org/rfc/rfc9114>. June 2022, <https://www.rfc-editor.org/info/rfc9114>.
[IANA-POLICY] [IANA-POLICY]
Cotton, M., Leiba, B., and T. Narten, "Guidelines for Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26, Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017, RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/rfc/rfc8126>. <https://www.rfc-editor.org/info/rfc8126>.
[QUIC] Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based [QUIC] Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based
Multiplexed and Secure Transport", RFC 9000, Multiplexed and Secure Transport", RFC 9000,
DOI 10.17487/RFC9000, May 2021, DOI 10.17487/RFC9000, May 2021,
<https://www.rfc-editor.org/rfc/rfc9000>. <https://www.rfc-editor.org/info/rfc9000>.
[QUIC-DGRAM]
Pauly, T., Kinnear, E., and D. Schinazi, "An Unreliable
Datagram Extension to QUIC", RFC 9221,
DOI 10.17487/RFC9221, March 2022,
<https://www.rfc-editor.org/info/rfc9221>.
[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/rfc/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/rfc/rfc8174>. May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[STRUCT-FIELD] [STRUCTURED-FIELDS]
Nottingham, M. and P-H. Kamp, "Structured Field Values for Nottingham, M. and P-H. Kamp, "Structured Field Values for
HTTP", RFC 8941, DOI 10.17487/RFC8941, February 2021, HTTP", RFC 8941, DOI 10.17487/RFC8941, February 2021,
<https://www.rfc-editor.org/rfc/rfc8941>. <https://www.rfc-editor.org/info/rfc8941>.
[TCP] Postel, J., "Transmission Control Protocol", STD 7, [TCP] Postel, J., "Transmission Control Protocol", STD 7,
RFC 793, DOI 10.17487/RFC0793, September 1981, RFC 793, DOI 10.17487/RFC0793, September 1981,
<https://www.rfc-editor.org/rfc/rfc793>. <https://www.rfc-editor.org/info/rfc793>.
6.2. Informative References 6.2. Informative References
[DPLPMTUD] Fairhurst, G., Jones, T., Tüxen, M., Rüngeler, I., and T. [DPLPMTUD] Fairhurst, G., Jones, T., Tüxen, M., Rüngeler, I., and T.
Völker, "Packetization Layer Path MTU Discovery for Völker, "Packetization Layer Path MTU Discovery for
Datagram Transports", RFC 8899, DOI 10.17487/RFC8899, Datagram Transports", RFC 8899, DOI 10.17487/RFC8899,
September 2020, <https://www.rfc-editor.org/rfc/rfc8899>. September 2020, <https://www.rfc-editor.org/info/rfc8899>.
[EXT-CONNECT2] [EXT-CONNECT2]
McManus, P., "Bootstrapping WebSockets with HTTP/2", McManus, P., "Bootstrapping WebSockets with HTTP/2",
RFC 8441, DOI 10.17487/RFC8441, September 2018, RFC 8441, DOI 10.17487/RFC8441, September 2018,
<https://www.rfc-editor.org/rfc/rfc8441>. <https://www.rfc-editor.org/info/rfc8441>.
[EXT-CONNECT3] [EXT-CONNECT3]
Hamilton, R., "Bootstrapping WebSockets with HTTP/3", Hamilton, R., "Bootstrapping WebSockets with HTTP/3",
RFC 9220, DOI 10.17487/RFC9220, June 2022, RFC 9220, DOI 10.17487/RFC9220, June 2022,
<https://www.rfc-editor.org/rfc/rfc9220>. <https://www.rfc-editor.org/info/rfc9220>.
[PRIORITY] Oku, K. and L. Pardue, "Extensible Prioritization Scheme [PRIORITY] Oku, K. and L. Pardue, "Extensible Prioritization Scheme
for HTTP", RFC 9218, DOI 10.17487/RFC9218, June 2022, for HTTP", RFC 9218, DOI 10.17487/RFC9218, June 2022,
<https://www.rfc-editor.org/rfc/rfc9218>. <https://www.rfc-editor.org/info/rfc9218>.
[WEBSOCKET] [WEBSOCKET]
Fette, I. and A. Melnikov, "The WebSocket Protocol", Fette, I. and A. Melnikov, "The WebSocket Protocol",
RFC 6455, DOI 10.17487/RFC6455, December 2011, RFC 6455, DOI 10.17487/RFC6455, December 2011,
<https://www.rfc-editor.org/rfc/rfc6455>. <https://www.rfc-editor.org/info/rfc6455>.
Acknowledgments Acknowledgments
Portions of this document were previously part of the QUIC DATAGRAM Portions of this document were previously part of the QUIC DATAGRAM
frame definition itself, the authors would like to acknowledge the frame definition itself; the authors would like to acknowledge the
authors of that document and the members of the IETF MASQUE working authors of that document and the members of the IETF MASQUE working
group for their suggestions. Additionally, the authors would like to group for their suggestions. Additionally, the authors would like to
thank Martin Thomson for suggesting the use of an HTTP/3 setting. thank Martin Thomson for suggesting the use of an HTTP/3 setting.
Furthermore, the authors would like to thank Ben Schwartz for writing Furthermore, the authors would like to thank Ben Schwartz for
the first proposal that used two layers of indirection. The final substantive input. The final design in this document came out of the
design in this document came out of the HTTP Datagrams Design Team, HTTP Datagrams Design Team, whose members were Alan Frindell, Alex
whose members were Alan Frindell, Alex Chernyakhovsky, Ben Schwartz, Chernyakhovsky, Ben Schwartz, Eric Rescorla, Marcus Ihlar, Martin
Eric Rescorla, Marcus Ihlar, Martin Thomson, Mike Bishop, Tommy Thomson, Mike Bishop, Tommy Pauly, Victor Vasiliev, and the authors
Pauly, Victor Vasiliev, and the authors of this document. The of this document. The authors thank Mark Nottingham and Philipp
authors thank Mark Nottingham and Philipp Tiesel for their helpful Tiesel for their helpful comments.
comments.
Authors' Addresses Authors' Addresses
David Schinazi David Schinazi
Google LLC Google LLC
1600 Amphitheatre Parkway 1600 Amphitheatre Parkway
Mountain View, CA 94043 Mountain View, CA 94043
United States of America United States of America
Email: dschinazi.ietf@gmail.com Email: dschinazi.ietf@gmail.com
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