]> Ericsson

magnus.westerlund@ericsson.com

ART AVTCORE It has been observed that specifications of new Real-time Transport Protocol (RTP) payload formats often forget to specify registration of the format's media type in the IANA registry "RTP Payload Formats Media Types" as recommended by RFC 8088. In practice this has no real impact. One reason is that the Media Types registry is the crucial registry to register any Media Type to establish the media type used to identified the format in various signaling usage. This document resolves the situation by first updating the RTP Payload Format Media Type registry to include all the known RTP payload formats at the time of writing, then it closes this IANA Registry for any future registration. Beyond instructing IANA to close this registry, the instructions to authors in RFC 8088 are updated to reflect this. About This Document Status information for this document may be found at . Discussion of this document takes place on the AVTCORE Working Group mailing list (), which is archived at . Subscribe at . Source for this draft and an issue tracker can be found at .

Introduction It has been observed that specifications of new Real-time Transport Protocol (RTP) payload formats often forget to specify registration of the format's media type in the IANA registry "RTP Payload Formats Media Types" as recommended by . In practice this has no real impact. This registry is not used for any purpose other than to track which media types actually have RTP payload formats. That purpose could be addressed through other means. The Media Types registry is the crucial registry to register any Media Type to establish the media type used to identify the format in various signalling usages, to avoid collisions, and to reference their specifications. To resolve this situation, this document performs the following actions. First, it updates the registry to include known RTP payload formats at the time of writing. Then, it closes the IANA Registry for RTP Payload Formats Media Types for future registration. Beyond instructing IANA to close this registry, the instructions to authors in are updated so that registration in the closed registry is no longer mentioned. It is unclear how the "RTP Payload formats Media Types" registry came into existence. The registry references as the instructions for this registry. However, reviewing that RFC we have been unable to find any text that defines its purpose and rules. Further attempts to find how the registry was created have failed to find any reference to its creation. It is likely this was created based on email or AD request. Thus, there is no known existing specification for this registry that needs to be updated when closing the registry.

Conventions The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 when, and only when, they appear in all capitals, as shown here.

Update to How To Write an RTP Payload Format How to write an RTP Payload format mandates in its section on IANA Considerations (Section 7.4) that RTP Payload formats shall register in RTP Payload Format media types: "Since all RTP payload formats contain a media type specification, they also need an IANA Considerations section. The media type name must be registered, and this is done by requesting that IANA register that media name. When that registration request is written, it shall also be requested that the media type is included under the "RTP Payload Format media types" sub-registry of the RTP registry (http://www.iana.org/assignments/rtp-parameters)." This paragraph is changed to the following: "Since all RTP payload formats contain a media type specification, they also need an IANA Considerations section. The media type name must be registered, and this is done by requesting that IANA register that media name in the Media Types registry (https://www.iana.org/assignments/media-types/media-types.xhtml)." Thus removing the need to register in the "RTP Payload Format media types".

IANA Considerations IANA is requested to add the following missing RTP Payload types to the "RTP Payload Format Media Types" registry . Payload Types to Register in RTP Payload Format Media Types

Media Type	Sub Type	Clock Rate (Hz)	Channels (audio)	Reference
application	flexfec			RFC8627
audio	EVRCNW	16000		RFC6884
audio	EVRCNW0	16000		RFC6884
audio	EVRCNW1	16000		RFC6884
audio	aptx			RFC7310
audio	opus	48000		RFC7587
audio	G711-0			RFC7650
audio	flexfec			RFC8627
text	flexfec			RFC8627
text	ttml+xml			RFC8759
video	VP8	90000		RFC7741
video	AV1	90000
video	HEVC	90000		RFC7798
video	smpte291			RFC8331
video	VVC	90000		RFC9328
video	EVC	90000		RFC9584
video	flexfec			RFC8627

IANA is requested to update the following RTP Payload types in the "RTP Payload Format Media Types" registry . Payload Types to update in RTP Payload Format Media Types

Media Type	Sub Type	Clock Rate (Hz)	Channels (audio)	Reference
audio	MP4A-LATM			RFC6416
video	MP4V-ES	90000		RFC6416

IANA is further requested to close the "RTP Payload Format Media Types" registry for any further registrations. IANA should add the following to the existing note for the registry: "This registry has been closed as it was considered redundant as all RTP Payload formats are part of the Media Types registry (https://www.iana.org/assignments/media-types/media-types.xhtml). For further motivation see (RFC-TBD1)." In addition it is requested that the existing note of "RTP Payload Format Media Types" registry is changed in the following way: OLD: Registration procedures and a registration template can be found in . NEW: It was previously stated that registration procedures and a registration template can be found in . This is not actually the case as discussed by [RFC-TBD1]. RFC-Editor Note: Please replace RFC-TBD1 with the RFC number of this specification and then remove this note.

Security Considerations This document has no security considerations as it defines an administrative rule change.

References Normative References In many standards track documents several words are used to signify the requirements in the specification. These words are often capitalized. This document defines these words as they should be interpreted in IETF documents. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. This document contains information on how best to write an RTP payload format specification. It provides reading tips, design practices, and practical tips on how to produce an RTP payload format specification quickly and with good results. A template is also included with instructions. RFC 2119 specifies common key words that may be used in protocol specifications. This document aims to reduce the ambiguity by clarifying that only UPPERCASE usage of the key words have the defined special meanings. Informative References This document specifies the procedure to register RTP payload formats as audio, video, or other media subtype names. This is useful in a text-based format description or control protocol to identify the type of an RTP transmission. [STANDARDS-TRACK]

Acknowledgments The author likes to thank Jonathan Lennox, Zaheduzzaman Sarker, Bernard Aboba, Elwyn Davies, Wes Hardaker, and Hyunsik Yang for review and editorial fixes.