rfc9193.original   rfc9193.txt 
Network Working Group A. Keränen Internet Engineering Task Force (IETF) A. Keränen
Internet-Draft Ericsson Request for Comments: 9193 Ericsson
Intended status: Standards Track C. Bormann Category: Standards Track C. Bormann
Expires: 24 April 2022 Universität Bremen TZI ISSN: 2070-1721 Universität Bremen TZI
21 October 2021 June 2022
SenML Data Value Content-Format Indication Sensor Measurement Lists (SenML) Fields for Indicating Data Value
draft-ietf-core-senml-data-ct-07 Content-Format
Abstract Abstract
The Sensor Measurement Lists (SenML) media type supports multiple The Sensor Measurement Lists (SenML) media types support multiple
types of values, from numbers to text strings and arbitrary binary types of values, from numbers to text strings and arbitrary binary
data values. In order to facilitate processing of binary data Data Values. In order to facilitate processing of binary Data
values, this document specifies a pair of new SenML fields for Values, this document specifies a pair of new SenML fields for
indicating the content format of those binary data values, i.e., indicating the content format of those binary Data Values, i.e.,
their Internet media type including parameters as well as any content their Internet media type, including parameters as well as any
codings applied. content codings applied.
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
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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
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Internet Standards is available in Section 2 of RFC 7841.
This Internet-Draft will expire on 24 April 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/rfc9193.
Copyright Notice Copyright Notice
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction
1.1. Evolution . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Evolution
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Terminology
3. SenML Content-Format ("ct") Field . . . . . . . . . . . . . . 5 3. SenML Content-Format ("ct") Field
4. SenML Base Content-Format ("bct") Field . . . . . . . . . . . 6 4. SenML Base Content-Format ("bct") Field
5. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 6 5. Examples
6. ABNF . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 6. ABNF
7. Security Considerations . . . . . . . . . . . . . . . . . . . 8 7. Security Considerations
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 8. IANA Considerations
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 9 9. References
9.1. Normative References . . . . . . . . . . . . . . . . . . 9 9.1. Normative References
9.2. Informative References . . . . . . . . . . . . . . . . . 10 9.2. Informative References
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 11 Acknowledgments
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11 Authors' Addresses
1. Introduction 1. Introduction
The Sensor Measurement Lists (SenML) media types [RFC8428] can be The Sensor Measurement Lists (SenML) media types [RFC8428] can be
used to send various kinds of data. In the example given in used to send various kinds of data. In the example given in
Figure 1, a temperature value, an indication whether a lock is open, Figure 1, a temperature value, an indication whether a lock is open,
and a data value (with SenML field "vd") read from an NFC reader is and a Data Value (with SenML field "vd") read from a Near Field
sent in a single SenML pack. The example is given in SenML JSON Communication (NFC) reader is sent in a single SenML Pack. The
representation, so the "vd" (data value) field is encoded as a example is given in SenML JSON representation, so the "vd" (Data
base64url string (without padding), as per Section 5 of [RFC8428]. Value) field is encoded as a base64url string (without padding), as
per Section 5 of [RFC8428].
[ [
{"bn":"urn:dev:ow:10e2073a01080063:","n":"temp","u":"Cel","v":7.1}, {"bn":"urn:dev:ow:10e2073a01080063:","n":"temp","u":"Cel","v":7.1},
{"n":"open","vb":false}, {"n":"open","vb":false},
{"n":"nfc-reader","vd":"aGkgCg"} {"n":"nfc-reader","vd":"aGkgCg"}
] ]
Figure 1: SenML pack with unidentified binary data Figure 1: SenML Pack with Unidentified Binary Data
The receiver is expected to know how to interpret the data in the The receiver is expected to know how to interpret the data in the
"vd" field based on the context, e.g., name of the data source and "vd" field based on the context, e.g., the name of the data source
out-of-band knowledge of the application. However, this context may and out-of-band knowledge of the application. However, this context
not always be easily available to entities processing the SenML pack, may not always be easily available to entities processing the SenML
especially if the pack is propagated over time and via multiple Pack, especially if the Pack is propagated over time and via multiple
entities. To facilitate automatic interpretation it is useful to be entities. To facilitate automatic interpretation, it is useful to be
able to indicate an Internet media type and, optionally, content able to indicate an Internet media type and, optionally, content
codings right in the SenML Record. codings right in the SenML Record.
The CoAP Content-Format (Section 12.3 of [RFC7252]) provides this The Constrained Application Protocol (CoAP) Content-Format
information in the form of a single unsigned integer; enclosing a (Section 12.3 of [RFC7252]) provides this information in the form of
Content-Format number (in this case number 60 as defined for content- a single unsigned integer. For instance, [RFC8949] defines the
type application/cbor in [RFC8949]) in the Record is illustrated in Content-Format number 60 for Content-Type application/cbor.
Enclosing this Content-Format number in the Record is illustrated in
Figure 2. All registered CoAP Content-Format numbers are listed in Figure 2. All registered CoAP Content-Format numbers are listed in
the COAP Content-Formats registry [IANA.core-parameters] as specified the "CoAP Content-Formats" registry [IANA.core-parameters], as
by Section 12.3 of [RFC7252]. Note that, at the time of writing, the specified by Section 12.3 of [RFC7252]. Note that, at the time of
structure of this registry only provides for zero or one content writing, the structure of this registry only provides for zero or one
codings; nothing in the present document needs to change if the content coding; nothing in the present document needs to change if
registry is extended to allow sequences of content codings. the registry is extended to allow sequences of content codings.
{"n":"nfc-reader", "vd":"gmNmb28YKg", "ct":"60"} {"n":"nfc-reader", "vd":"gmNmb28YKg", "ct":"60"}
Figure 2: SenML Record with binary data identified as CBOR Figure 2: SenML Record with Binary Data Identified as CBOR
In this example SenML Record, the data value contains a string "foo" In this example SenML Record, the Data Value contains a string "foo"
and a number 42 encoded in a CBOR [RFC8949] array. Since the example and a number 42 encoded in a Concise Binary Object Representation
above uses the JSON format of SenML, the data value containing the (CBOR) [RFC8949] array. Since the example above uses the JSON format
binary CBOR value is base64-encoded (Section 5 of [RFC4648]). The of SenML, the Data Value containing the binary CBOR value is base64
data value after base64 decoding is shown with CBOR diagnostic encoded (Section 5 of [RFC4648]). The Data Value after base64
notation in Figure 3. decoding is shown with CBOR diagnostic notation in Figure 3.
82 # array(2) 82 # array(2)
63 # text(3) 63 # text(3)
666F6F # "foo" 666F6F # "foo"
18 2A # unsigned(42) 18 2A # unsigned(42)
Figure 3: Example Data Value in CBOR diagnostic notation Figure 3: Example Data Value in CBOR Diagnostic Notation
1.1. Evolution 1.1. Evolution
As with SenML in general, there is no expectation that the creator of As with SenML in general, there is no expectation that the creator of
a SenML pack knows (or has negotiated with) each consumer of that a SenML Pack knows (or has negotiated with) each consumer of that
pack, which may be very remote in space and particularly in time. Pack, which may be very remote in space and particularly in time.
This means that the SenML creator in general has no way to know This means that the SenML creator in general has no way to know
whether the consumer knows: whether the consumer knows:
* each specific media-type-name used * each specific Media-Type-Name used,
* each parameter and each parameter value used * each parameter and each parameter value used,
* each content coding in use * each content coding in use, and
* each Content-Format number in use for a combination of these
* each Content-Format number in use for a combination of these.
What SenML, as well as the new fields defined here, guarantees is What SenML, as well as the new fields defined here, guarantees is
that a recipient implementation _knows_ when it needs to be updated that a recipient implementation _knows_ when it needs to be updated
to understand these field values and the values controlled by them; to understand these field values and the values controlled by them;
registries are used to evolve these name spaces in a controlled way. registries are used to evolve these name spaces in a controlled way.
SenML packs can be processed by a consumer while not understanding SenML Packs can be processed by a consumer while not understanding
all the information in them, and information can generally be all the information in them, and information can generally be
preserved in this processing such that it is useful for further preserved in this processing such that it is useful for further
consumers. consumers.
2. Terminology 2. Terminology
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.
Media Type: A registered label for representations (byte strings) Media type: A registered label for representations (byte strings)
prepared for interchange, identified by a Media-Type-Name prepared for interchange [RFC1590] [RFC6838], identified by a
[RFC1590], [RFC6838]. Media-Type-Name.
Media-Type-Name: A combination of a type-name and a subtype-name Media-Type-Name: A combination of a type-name and a subtype-name
registered in [IANA.media-types] as per [RFC6838], conventionally registered in [IANA.media-types], as per [RFC6838], conventionally
identified by the two names separated by a slash. identified by the two names separated by a slash.
Content-Type: A Media-Type-Name, optionally associated with Content-Type: A Media-Type-Name, optionally associated with
parameters (Section 5 of [RFC2045], separated from the Media-Type- parameters (Section 5 of [RFC2045], separated from the Media-Type-
Name and from each other by a semicolon). In HTTP and many other Name and from each other by a semicolon). In HTTP and many other
protocols, used in a Content-Type header field. protocols, it is used in a Content-Type header field.
content coding: A name registered in the HTTP Content Coding Content coding: A name registered in the "HTTP Content Coding
registry [IANA.http-parameters] as specified by Sections 16.6.1 Registry" [IANA.http-parameters], as specified by Sections 16.6.1
and 18.6 of [I-D.ietf-httpbis-semantics], indicating an encoding and 18.6 of [RFC9110], indicating an encoding transformation with
transformation with semantics further specified in Section 8.4.1 semantics further specified in Section 8.4.1 of [RFC9110].
of [I-D.ietf-httpbis-semantics]. Confusingly, in HTTP, content Confusingly, in HTTP, content coding values are found in a header
coding values are found in a header field called "Content- field called "Content-Encoding"; however, "content coding" is the
Encoding", however "content coding" is the correct term for the correct term for the process and the registered values.
process and the registered values.
content format: the combination of a Content-Type and zero or more Content format: The combination of a Content-Type and zero or more
content codings, identified by (1) a numeric identifier defined in content codings, identified by (1) a numeric identifier defined in
the COAP Content-Formats registry [IANA.core-parameters] as per the "CoAP Content-Formats" registry [IANA.core-parameters], as per
Section 12.3 of [RFC7252] (referred to as Content-Format number), Section 12.3 of [RFC7252] (referred to as Content-Format number),
or (2) a Content-Format-String. or (2) a Content-Format-String.
Content-Format-String: the string representation of the combination Content-Format-String: The string representation of the combination
of a Content-Type and zero or more content codings. of a Content-Type and zero or more content codings.
Content-Format-Spec: the string representation of a content format; Content-Format-Spec: The string representation of a content format;
either a Content-Format-String or the (decimal) string either a Content-Format-String or the (decimal) string
representation of a Content-Format number. representation of a Content-Format number.
Readers should also be familiar with the terms and concepts discussed Readers should also be familiar with the terms and concepts discussed
in [RFC8428]. in [RFC8428].
3. SenML Content-Format ("ct") Field 3. SenML Content-Format ("ct") Field
When a SenML Record contains a Data Value field ("vd"), the Record When a SenML Record contains a Data Value field ("vd"), the Record
MAY also include a Content-Format indication field, using label "ct". MAY also include a Content-Format indication field, using label "ct".
The value of this field is a Content-Format-Spec, i.e., one of: The value of this field is a Content-Format-Spec, i.e., one of the
following:
* a CoAP Content-Format number in decimal form with no leading zeros * a CoAP Content-Format number in decimal form with no leading zeros
(except for the value "0" itself). This value represents an (except for the value "0" itself). This value represents an
unsigned integer in the range of 0-65535, similar to the "ct" unsigned integer in the range of 0-65535, similar to the "ct"
attribute defined in Section 7.2.1 of [RFC7252] for CoRE Link attribute defined in Section 7.2.1 of [RFC7252] for CoRE Link
Format [RFC6690]). Format [RFC6690].
* or a Content-Format-String containing a Content-Type and zero or * a Content-Format-String containing a Content-Type and zero or more
more content codings (see below). content codings (see below).
The syntax of this field is formally defined in Section 6. The syntax of this field is formally defined in Section 6.
The CoAP Content-Format number provides a simple and efficient way to The CoAP Content-Format number provides a simple and efficient way to
indicate the type of the data. Since some Internet media types and indicate the type of the data. Since some Internet media types and
their content coding and parameter alternatives do not have assigned their content coding and parameter alternatives do not have assigned
CoAP Content-Format numbers, using Content-Type and zero or more CoAP Content-Format numbers, using Content-Type and zero or more
content codings is also allowed. Both methods use a string value in content codings is also allowed. Both methods use a string value in
the "ct" field to keep its data type consistent across uses. When the "ct" field to keep its data type consistent across uses. When
the "ct" field contains only digits, it is interpreted as a CoAP the "ct" field contains only digits, it is interpreted as a CoAP
Content-Format number. Content-Format number.
To indicate that one or more content codings are used with a Content- To indicate that one or more content codings are used with a Content-
Type, each of the content coding values is appended to the Content- Type, each of the content coding values is appended to the Content-
Type value (media type and parameters, if any), separated by a "@" Type value (media type and parameters, if any), separated by an "@"
sign, in the order of the content codings were applied (the same sign, in the order of when the content codings were applied (the same
order as in Section 8.4 of [I-D.ietf-httpbis-semantics]). For order as in Section 8.4 of [RFC9110]). For example (using a content
example (using a content coding value of "deflate" as defined in coding value of "deflate", as defined in Section 8.4.1.2 of
Section 8.4.1.2 of [I-D.ietf-httpbis-semantics]): [RFC9110]):
text/plain; charset=utf-8@deflate text/plain; charset=utf-8@deflate
If no "@" sign is present after the media type and parameters, then If no "@" sign is present after the media type and parameters, then
no content coding has been specified, and the "identity" content no content coding has been specified, and the "identity" content
coding is used -- no encoding transformation is employed. coding is used -- no encoding transformation is employed.
4. SenML Base Content-Format ("bct") Field 4. SenML Base Content-Format ("bct") Field
The Base Content-Format Field, label "bct", provides a default value The Base Content-Format field, label "bct", provides a default value
for the Content-Format Field (label "ct") within its range. The for the Content-Format field (label "ct") within its range. The
range of the base field includes the Record containing it, up to (but range of the base field includes the Record containing it, up to (but
not including) the next Record containing a "bct" field, if any, or not including) the next Record containing a "bct" field, if any, or
up to the end of the pack otherwise. The process of resolving up to the end of the Pack otherwise. The process of resolving
(Section 4.6 of [RFC8428]) this base field is performed by adding its (Section 4.6 of [RFC8428]) this base field is performed by adding its
value with the label "ct" to all Records in this range that carry a value with the label "ct" to all Records in this range that carry a
"vd" field but do not already contain a Content-Format ("ct") field. "vd" field but do not already contain a Content-Format ("ct") field.
Figure 4 shows a variation of Figure 2 with multiple records, with Figure 4 shows a variation of Figure 2 with multiple records, with
the "nfc-reader" records resolving to the base field value "60" and the "nfc-reader" records resolving to the base field value "60" and
the "iris-photo" record overriding this with the "image/png" media the "iris-photo" record overriding this with the "image/png" media
type (actual data left out for brevity). type (actual data left out for brevity).
[ [
{"n":"nfc-reader", "vd":"gmNmb28YKg", {"n":"nfc-reader", "vd":"gmNmb28YKg",
"bct":"60", "bt":1627430700}, "bct":"60", "bt":1627430700},
{"n":"nfc-reader", "vd":"gmNiYXIYKw", "t":10}, {"n":"nfc-reader", "vd":"gmNiYXIYKw", "t":10},
{"n":"iris-photo", "vd":".....", "ct":"image/png", "t":10}, {"n":"iris-photo", "vd":".....", "ct":"image/png", "t":10},
{"n":"nfc-reader", "vd":"gmNiYXoYLA", "t":20} {"n":"nfc-reader", "vd":"gmNiYXoYLA", "t":20}
] ]
Figure 4: SenML pack with bct field Figure 4: SenML Pack with the bct Field
5. Examples 5. Examples
The following examples are valid values for the "ct" and "bct" fields The following examples are valid values for the "ct" and "bct" fields
(explanation/comments in parentheses): (explanation/comments in parentheses):
* "60" (CoAP Content-Format number for "application/cbor") * "60" (CoAP Content-Format number for "application/cbor")
* "0" (CoAP Content-Format number for "text/plain" with parameter * "0" (CoAP Content-Format number for "text/plain" with parameter
"charset=utf-8") "charset=utf-8")
skipping to change at page 7, line 4 skipping to change at line 283
Content-Format number) Content-Format number)
* "application/json@deflate" (JSON Content-Type with "deflate" as * "application/json@deflate" (JSON Content-Type with "deflate" as
content coding -- equivalent to "11050" CoAP Content-Format content coding -- equivalent to "11050" CoAP Content-Format
number) number)
* "application/json@deflate@aes128gcm" (JSON Content-Type with * "application/json@deflate@aes128gcm" (JSON Content-Type with
"deflate" followed by "aes128gcm" as content codings) "deflate" followed by "aes128gcm" as content codings)
* "text/csv" (Comma-Separated Values (CSV) [RFC4180] Content-Type) * "text/csv" (Comma-Separated Values (CSV) [RFC4180] Content-Type)
* "text/csv;header=present@gzip" (CSV with header row, using "gzip" * "text/csv;header=present@gzip" (CSV with header row, using "gzip"
as content coding) as content coding)
6. ABNF 6. ABNF
This specification provides a formal definition of the syntax of This specification provides a formal definition of the syntax of
Content-Format-Spec strings using ABNF notation [RFC5234], which Content-Format-Spec strings using ABNF notation [RFC5234], which
contains three new rules and a number of rules collected and adapted contains three new rules and a number of rules collected and adapted
from various RFCs [I-D.ietf-httpbis-semantics] [RFC6838] [RFC5234] from various RFCs [RFC9110] [RFC6838] [RFC5234] [RFC8866].
[RFC8866].
; New in this document ; New in this document
Content-Format-Spec = Content-Format-Number / Content-Format-String Content-Format-Spec = Content-Format-Number / Content-Format-String
Content-Format-Number = "0" / (POS-DIGIT *DIGIT) Content-Format-Number = "0" / (POS-DIGIT *DIGIT)
Content-Format-String = Content-Type *("@" Content-Coding) Content-Format-String = Content-Type *("@" Content-Coding)
; Cleaned up from [RFC-httpbis-semantics], ; Cleaned up from RFC 9110,
; leaving only SP as blank space, ; leaving only SP as blank space,
; removing legacy 8-bit characters, and ; removing legacy 8-bit characters, and
; leaving the parameter as mandatory with each semicolon: ; leaving the parameter as mandatory with each semicolon:
Content-Type = Media-Type-Name *( *SP ";" *SP parameter ) Content-Type = Media-Type-Name *( *SP ";" *SP parameter )
parameter = token "=" ( token / quoted-string ) parameter = token "=" ( token / quoted-string )
token = 1*tchar token = 1*tchar
tchar = "!" / "#" / "$" / "%" / "&" / "'" / "*" tchar = "!" / "#" / "$" / "%" / "&" / "'" / "*"
/ "+" / "-" / "." / "^" / "_" / "`" / "|" / "~" / "+" / "-" / "." / "^" / "_" / "`" / "|" / "~"
/ DIGIT / ALPHA / DIGIT / ALPHA
quoted-string = %x22 *( qdtext / quoted-pair ) %x22 quoted-string = %x22 *( qdtext / quoted-pair ) %x22
qdtext = SP / %x21 / %x23-5B / %x5D-7E qdtext = SP / %x21 / %x23-5B / %x5D-7E
quoted-pair = "\" ( SP / VCHAR ) quoted-pair = "\" ( SP / VCHAR )
; Adapted from section 8.4.1 of [RFC-httpbis-semantics] ; Adapted from Section 8.4.1 of RFC 9110
Content-Coding = token Content-Coding = token
; Adapted from various specs ; Adapted from various specs
Media-Type-Name = type-name "/" subtype-name Media-Type-Name = type-name "/" subtype-name
; RFC 6838 ; From RFC 6838
type-name = restricted-name type-name = restricted-name
subtype-name = restricted-name subtype-name = restricted-name
restricted-name = restricted-name-first *126restricted-name-chars restricted-name = restricted-name-first *126restricted-name-chars
restricted-name-first = ALPHA / DIGIT restricted-name-first = ALPHA / DIGIT
restricted-name-chars = ALPHA / DIGIT / "!" / "#" / restricted-name-chars = ALPHA / DIGIT / "!" / "#" /
"$" / "&" / "-" / "^" / "_" "$" / "&" / "-" / "^" / "_"
restricted-name-chars =/ "." ; Characters before first dot always restricted-name-chars =/ "." ; Characters before first dot always
; specify a facet name ; specify a facet name
restricted-name-chars =/ "+" ; Characters after last plus always restricted-name-chars =/ "+" ; Characters after last plus always
; specify a structured syntax suffix ; specify a structured syntax suffix
; Boilerplate from RFC 5234 and RFC 8866 ; Boilerplate from RFC 5234 and RFC 8866
DIGIT = %x30-39 ; 0 – 9 DIGIT = %x30-39 ; 0 - 9
POS-DIGIT = %x31-39 ; 1 – 9 POS-DIGIT = %x31-39 ; 1 - 9
ALPHA = %x41-5A / %x61-7A ; A – Z / a – z ALPHA = %x41-5A / %x61-7A ; A - Z / a - z
SP = %x20 SP = %x20
VCHAR = %x21-7E ; printable ASCII (no SP) VCHAR = %x21-7E ; printable ASCII (no SP)
Figure 5: ABNF syntax of Content-Format-Spec Figure 5: ABNF Syntax of Content-Format-Spec
// RFC editor: Please replace [RFC-httpbis-semantics] by what gets
// published from [I-D.ietf-httpbis-semantics].
7. Security Considerations 7. Security Considerations
The indication of a media type in the data does not exempt a The indication of a media type in the data does not exempt a
consuming application from properly checking its inputs. Also, the consuming application from properly checking its inputs. Also, the
ability for an attacker to supply crafted SenML data that specify ability for an attacker to supply crafted SenML data that specifies
media types chosen by the attacker may expose vulnerabilities of media types chosen by the attacker may expose vulnerabilities of
handlers for these media types to the attacker. This includes handlers for these media types to the attacker. This includes
"decompression bombs", compressed data that is crafted to decompress "decompression bombs", compressed data that is crafted to decompress
to extremely large data items. to extremely large data items.
8. IANA Considerations 8. IANA Considerations
(Note to RFC Editor: Please replace all occurrences of "RFC-AAAA" IANA has assigned the following new labels in the "SenML Labels"
with the RFC number of this specification and remove this note.) subregistry of the "Sensor Measurement Lists (SenML)" registry
[IANA.senml] (as defined in Section 12.2 of [RFC8428]) for the
IANA is requested to assign new labels in the "SenML Labels" Content-Format indication, as per Table 1:
subregistry of the SenML registry [IANA.senml] (as defined in
Section 12.2 of [RFC8428]) for the Content-Format indication as per
Table 1:
+=====================+=======+===========+==========+===========+ +=====================+=======+===========+==========+===========+
| Name | Label | JSON Type | XML Type | Reference | | Name | Label | JSON Type | XML Type | Reference |
+=====================+=======+===========+==========+===========+ +=====================+=======+===========+==========+===========+
| Base Content-Format | bct | String | string | RFC-AAAA | | Base Content-Format | bct | String | string | RFC 9193 |
+---------------------+-------+-----------+----------+-----------+ +---------------------+-------+-----------+----------+-----------+
| Content-Format | ct | String | string | RFC-AAAA | | Content-Format | ct | String | string | RFC 9193 |
+---------------------+-------+-----------+----------+-----------+ +---------------------+-------+-----------+----------+-----------+
Table 1: IANA Registration for new SenML Labels Table 1: IANA Registration for New SenML Labels
Note that as per Section 12.2 of [RFC8428], no CBOR labels or EXI Note that, per Section 12.2 of [RFC8428], no CBOR labels nor
schemaId values (EXI ID column) are supplied. Efficient XML Interchange (EXI) schemaId values (EXI ID column) are
supplied.
9. References 9. References
9.1. Normative References 9.1. Normative References
[I-D.ietf-httpbis-semantics]
Fielding, R. T., Nottingham, M., and J. Reschke, "HTTP
Semantics", Work in Progress, Internet-Draft, draft-ietf-
httpbis-semantics-19, 12 September 2021,
<https://www.ietf.org/archive/id/draft-ietf-httpbis-
semantics-19.txt>.
[IANA.core-parameters] [IANA.core-parameters]
IANA, "Constrained RESTful Environments (CoRE) IANA, "Constrained RESTful Environments (CoRE)
Parameters", Parameters",
<https://www.iana.org/assignments/core-parameters>. <https://www.iana.org/assignments/core-parameters>.
[IANA.http-parameters] [IANA.http-parameters]
IANA, "Hypertext Transfer Protocol (HTTP) Parameters", IANA, "Hypertext Transfer Protocol (HTTP) Parameters",
<https://www.iana.org/assignments/http-parameters>. <https://www.iana.org/assignments/http-parameters>.
[IANA.media-types] [IANA.media-types]
skipping to change at page 10, line 29 skipping to change at line 430
[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/info/rfc8174>. May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8428] Jennings, C., Shelby, Z., Arkko, J., Keranen, A., and C. [RFC8428] Jennings, C., Shelby, Z., Arkko, J., Keranen, A., and C.
Bormann, "Sensor Measurement Lists (SenML)", RFC 8428, Bormann, "Sensor Measurement Lists (SenML)", RFC 8428,
DOI 10.17487/RFC8428, August 2018, DOI 10.17487/RFC8428, August 2018,
<https://www.rfc-editor.org/info/rfc8428>. <https://www.rfc-editor.org/info/rfc8428>.
[RFC9110] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke,
Ed., "HTTP Semantics", RFC 9110, STD 97,
DOI 10.17487/RFC9110, June 2022,
<https://www.rfc-editor.org/rfc/rfc9110>.
9.2. Informative References 9.2. Informative References
[RFC1590] Postel, J., "Media Type Registration Procedure", RFC 1590, [RFC1590] Postel, J., "Media Type Registration Procedure", RFC 1590,
DOI 10.17487/RFC1590, March 1994, DOI 10.17487/RFC1590, March 1994,
<https://www.rfc-editor.org/info/rfc1590>. <https://www.rfc-editor.org/info/rfc1590>.
[RFC4180] Shafranovich, Y., "Common Format and MIME Type for Comma- [RFC4180] Shafranovich, Y., "Common Format and MIME Type for Comma-
Separated Values (CSV) Files", RFC 4180, Separated Values (CSV) Files", RFC 4180,
DOI 10.17487/RFC4180, October 2005, DOI 10.17487/RFC4180, October 2005,
<https://www.rfc-editor.org/info/rfc4180>. <https://www.rfc-editor.org/info/rfc4180>.
skipping to change at page 11, line 15 skipping to change at line 469
[RFC8866] Begen, A., Kyzivat, P., Perkins, C., and M. Handley, "SDP: [RFC8866] Begen, A., Kyzivat, P., Perkins, C., and M. Handley, "SDP:
Session Description Protocol", RFC 8866, Session Description Protocol", RFC 8866,
DOI 10.17487/RFC8866, January 2021, DOI 10.17487/RFC8866, January 2021,
<https://www.rfc-editor.org/info/rfc8866>. <https://www.rfc-editor.org/info/rfc8866>.
[RFC8949] Bormann, C. and P. Hoffman, "Concise Binary Object [RFC8949] Bormann, C. and P. Hoffman, "Concise Binary Object
Representation (CBOR)", STD 94, RFC 8949, Representation (CBOR)", STD 94, RFC 8949,
DOI 10.17487/RFC8949, December 2020, DOI 10.17487/RFC8949, December 2020,
<https://www.rfc-editor.org/info/rfc8949>. <https://www.rfc-editor.org/info/rfc8949>.
Acknowledgements Acknowledgments
The authors would like to thank Sérgio Abreu for the discussions The authors would like to thank Sérgio Abreu for the discussions
leading to the design of this extension and Isaac Rivera for reviews leading to the design of this extension and Isaac Rivera for reviews
and feedback. Klaus Hartke suggested not burdening this draft with a and feedback. Klaus Hartke suggested not burdening this document
separate mandatory-to-implement version of the fields. Alexey with a separate mandatory-to-implement version of the fields. Alexey
Melnikov, Jim Schaad, and Thomas Fossati provided helpful comments at Melnikov, Jim Schaad, and Thomas Fossati provided helpful comments at
Working-Group last call. Marco Tiloca asked for clarifying and using Working Group Last Call. Marco Tiloca asked for clarifying and using
the term Content-Format-Spec. the term Content-Format-Spec.
Authors' Addresses Authors' Addresses
Ari Keränen Ari Keränen
Ericsson Ericsson
FI-02420 Jorvas FI-02420 Jorvas
Finland Finland
Email: ari.keranen@ericsson.com Email: ari.keranen@ericsson.com
Carsten Bormann Carsten Bormann
Universität Bremen TZI Universität Bremen TZI
Postfach 330440 Postfach 330440
D-28359 Bremen D-28359 Bremen
Germany Germany
Phone: +49-421-218-63921 Phone: +49-421-218-63921
Email: cabo@tzi.org Email: cabo@tzi.org
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