Status of This Memo

This is an Internet Standards Track document.¶

This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 7841.¶

Information about the current status of this document, any errata, and how to provide feedback on it may be obtained athttps://www.rfc-editor.org/info/rfc9751.¶

Copyright Notice

Copyright (c) 2025 IETF Trust and the persons identified as the document authors. All rights reserved.¶

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License.¶

Table of Contents

1.Introduction

Sometimes, authors defining new Real-time Transport Protocol (RTP) payload formats forgot to specify registration of the format's media type in the "RTP Payload Format Media Types" registry[RTP-FORMATS] as recommended by[RFC8088]. In practice, this has no real impact. This registryis not used for any purpose other than to track which media types actually haveRTP payload formats, which can be done through other means.¶

It is required that media types be registered in the "Media Types" registry[MEDIA-TYPES] to identify the format in various signalling usages, avoid collisions, and reference the defining specifications.¶

To resolve this situation, this document:¶

• updates the "RTP Payload Format Media Types" registry to include known RTP payload formats at the time of writing,¶
• closes the "RTP Payload Format Media Types" registry to future registrations and lists this RFC as a reference, and¶
• removes from[RFC8088] the instruction to register RTP payload formats in the "RTP Payload Format Media Types" registry.¶

The origins of the "RTP Payload Format Media Types" registry, as referenced in[RTP-FORMATS], are unclear. The registry cites[RFC4855] as providing theinstructions for its maintenance. However, upon reviewing RFC 4855, no text hasbeen found that defines the registry's purpose and operational rules. Furtherattempts to trace the registry's creation have failed to uncover any referencesto its establishment. It is likely that the registry was created based onemail correspondence or at the request of an Area Director.Consequently, there is no known specification for this registry thatrequires updating upon its closure.¶

2.Update to How to Write an RTP Payload Format

The IANA Considerations section of "How to write an RTP Payload Format" (Section 7.4 of [RFC8088]) mandates that RTP payload formats shallbe registered in the "RTP Payload Format Media Types" registry. The following paragraph is updated as shown below, thus removing the need for media types to be registered in the "RTP Payload Format Media Types" registry. Note that this update does not impact the rest of RFC 8088's status as an Informational RFC.¶

OLD:¶

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).¶

NEW:¶

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/).¶

3.IANA Considerations

IANA has added the following RTP payload types tothe "RTP Payload Format Media Types" registry[RTP-FORMATS].¶

IANA has updated the following entries in the "RTP Payload Format Media Types" registry[RTP-FORMATS].¶

IANA has also closed the "RTP Payload Format Media Types" registry[RTP-FORMATS] to any further registrations. IANA added the following to the registry note:¶

NEW:¶

This registry has been closed; it was considered redundant because all RTP payload formats are part of the[Media Types registry]. See RFC 9751 for further details.¶

In addition, IANA updated the note in the "RTP Payload Format Media Types" registry[RTP-FORMATS] as follows:¶

OLD:¶

Registration procedures and a registration template can be found in[RFC4855].¶

NEW:¶

It was previously stated that registration procedures and a registration template can be found in[RFC4855]. As documented in RFC 9751, this is not the case.¶

4.Security Considerations

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

5.References

Acknowledgments

The author thanksJonathan Lennox,Zaheduzzaman Sarker,Bernard Aboba,Elwyn Davies,Wes Hardaker,Gunter Van de Velde,Éric Vyncke,Mahesh Jethanandani, andHyunsik Yang for their reviews and editorial fixes.¶

Author's Address