avtcore T.B.Internet Engineering Task Force (IETF) T. TerriberryInternet-DraftRequest for Comments: 7007 Mozilla Corporation Updates: 3551(if approved) July 02,August 2013Intended status:Category: Standards TrackExpires: January 03, 2014ISSN: 2070-1721 Update to Remove DVI4 from the Recommended Codecs for the RTP Profile for Audio and Video Conferences with Minimal Control (RTP/AVP)draft-ietf-avtcore-avp-codecs-03Abstract 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),(RTP/AVPF), and the Extended Secure RTP Profile for RTCP-Based Feedback (RTP/SAVPF). This document updates RFC 3551, the RTP/AVP profile (and by extension, the profiles that build uponit)it), to reflect changes in audio codec usage sincethethat document was originally published. Status of This Memo ThisInternet-Draftissubmitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documentsan Internet Standards Track document. This document is a product of the Internet Engineering Task Force (IETF).Note that other groups may also distribute working documents as Internet-Drafts. The listIt represents the consensus ofcurrent Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents validthe IETF community. It has received public review and has been approved fora maximumpublication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 ofsix monthsRFC 5741. Information about the current status of this document, any errata, and how to provide feedback on it may beupdated, replaced, or obsoleted by other documentsobtained atany time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on January 03, 2014.http://www.rfc-editor.org/info/rfc7007. Copyright Notice Copyright (c) 2013 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 (http://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 Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction. . . . . . . . . . . . . . . . . . . . . . . . 2....................................................2 2. Terminology. . . . . . . . . . . . . . . . . . . . . . . . . 2.....................................................2 3. Updates to RFC 3551. . . . . . . . . . . . . . . . . . . . . 2.............................................3 3.1. Updates to Section 6. . . . . . . . . . . . . . . . . . 3of RFC 3551 ...........................3 4. Security Considerations. . . . . . . . . . . . . . . . . . . 3.........................................3 5.IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3 6.Acknowledgments. . . . . . . . . . . . . . . . . . . . . . . 3 7..................................................3 6. References. . . . . . . . . . . . . . . . . . . . . . . . . 3 7.1.......................................................4 6.1. Normative References. . . . . . . . . . . . . . . . . . 3 7.2........................................4 6.2. Informative References. . . . . . . . . . . . . . . . . 3 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 4.....................................4 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 there is little reason to use it when much more modern codecs are available. This document updates the recommended audio codec selection for the RTP/AVP profileto removeand removes the SHOULD for DVI4. By extension, this also updates the profileswhichthat 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 forthbelowin Section3.1.3.1: 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 6Inof RFC 3551 This document updates the final paragraph of Section6, replace,6 of RFC 3551 by replacing "payload types 0 (PCMU) and 5(DVI4),"(DVI4)" with "payload type 0(PCMU)." Also,(PCMU)". We also add a final sentence tothisthat paragraph that states, "Some environments necessitate support forPCMU."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 necessitate 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.7.6. References7.1.6.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3551] Schulzrinne, H. and S. Casner, "RTP Profile for Audio and Video Conferences with Minimal Control", STD 65, RFC 3551, July 2003.7.2.6.2. Informative References [RFC3711] Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K. Norrman, "The Secure Real-time Transport Protocol (SRTP)", RFC 3711, March 2004. [RFC4585] Ott, J., Wenger, S., Sato, N., Burmeister, C., and J. Rey, "Extended RTP Profile for Real-time Transport Control Protocol (RTCP)-Based Feedback (RTP/AVPF)", RFC 4585, July 2006. [RFC5124] Ott, J. and E. Carrara, "Extended Secure RTP Profile for Real-time Transport Control Protocol (RTCP)-Based Feedback (RTP/SAVPF)", RFC 5124, February 2008. Author's Address Timothy B. Terriberry Mozilla Corporation 650 Castro Street Mountain View, CA 94041 USA Phone: +1 650 903-0800Email:EMail: tterribe@xiph.org