Update to Recommended Codecs for the RTP Profile for Audio and Video Conferences with Minimal Control (RTP/AVP)
draft-ietf-avtcore-avp-codecs-02

Abstract

The RTP Profile for Audio and Video Conferences with Minimal Control (RTP/AVP) is the basis for many other profiles, such as the Secure Real-time Transport Protocol (RTP/SAVP), the Extended RTP Profile for Real-time Transport Control Protocol (RTCP)-Based Feedback (RTP/AVPF), and the Extended Secure RTP Profile for RTCP-Based Feedback (RTP/SAVPF). This document updates the RTP/AVP profile (and by extension, the profiles that build upon it) to reflect changes in audio codec usage since the document was originally published.

Status of This Memo

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This Internet-Draft will expire on October 13, 2013.

Copyright Notice

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Table of Contents

• 1. Introduction
• 2. Terminology
• 3. Updates to RFC 3551
• 3.1. Updates to Section 6
• 4. Security Considerations
• 5. IANA Considerations
• 6. Acknowledgments
• 7. References
• 7.1. Normative References
• 7.2. Informative References
• Author's Address

1. Introduction

[RFC3551] says that audio applications operating under the RTP/AVP profile SHOULD be able to send and receive PCMU and DVI4. However, in practice, many RTP deployments do not support DVI4, and its utility is limited in the presence of much more modern codecs. This document updates the recommended audio codec selection for the RTP/AVP profile to remove the SHOULD for DVI4. By extension, this also updates the profiles which build on RTP/AVP, including RTP/SAVP [RFC3711], RTP/AVPF [RFC4585], and RTP/SAVPF [RFC5124].

2. Terminology

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].

3. Updates to RFC 3551

The following text of [RFC3551] is hereby updated as set forth below in Section 3.1.

Audio applications operating under this profile SHOULD, at a minimum, be able to send and/or receive payload types 0 (PCMU) and 5 (DVI4). This allows interoperability without format negotiation and ensures successful negotiation with a conference control protocol.

3.1. Updates to Section 6

In the final paragraph of Section 6, replace, "payload types 0 (PCMU) and 5 (DVI4)," with "payload type 0 (PCMU)." Also, add a final sentence to this paragraph that states, "Some environments REQUIRE support for PCMU." This results in the following paragraph:

Audio applications operating under this profile SHOULD, at a minimum, be able to send and/or receive payload type 0 (PCMU). This allows interoperability without format negotiation and ensures successful negotiation with a conference control protocol. Some environments REQUIRE support for PCMU.

4. Security Considerations

This document does not introduce any new security considerations for [RFC3551].

5. IANA Considerations

This document has no actions for IANA.

6. Acknowledgments

Thanks to Colin Perkins for suggesting this update.

7. References

7.1. Normative References

7.2. Informative References

Author's Address