RTP Clock Source Signalling
RFC 7273

Approval announcement
Draft of message to be sent after approval:

From: The IESG <iesg-secretary@ietf.org>
To: IETF-Announce <ietf-announce@ietf.org>
Cc: RFC Editor <rfc-editor@rfc-editor.org>,
    avtcore mailing list <avt@ietf.org>,
    avtcore chair <avtcore-chairs@tools.ietf.org>
Subject: Protocol Action: 'RTP Clock Source Signalling' to Proposed Standard (draft-ietf-avtcore-clksrc-11.txt)

The IESG has approved the following document:
- 'RTP Clock Source Signalling'
  (draft-ietf-avtcore-clksrc-11.txt) as Proposed Standard

This document is the product of the Audio/Video Transport Core
Maintenance Working Group.

The IESG contact persons are Alissa Cooper and Richard Barnes.

A URL of this Internet Draft is:
http://datatracker.ietf.org/doc/draft-ietf-avtcore-clksrc/


Technical Summary

NTP format timestamps are used by several RTP protocols for 
synchronisation and statistical measurements.  This memo specifies SDP 
signalling identifying timestamp reference clock sources and SDP 
signalling identifying the media clock sources in a multimedia session.


Working Group Summary

This document was written as a result of discussion on another draft 
which made it clear that there is a need to be able to specify the clock 
used for RTP in order to achieve better synchronization between sources. 
It was seen as a general problem and this document represent the WG 
consensus.


Document Quality

The authors are aware of two implementation that use at least some of 
the signaling capabilities described in this draft: http://
soundandpicture.com/2013/11/axia-announces-first-broadcast-product-with-
aes67-compliance/ and http://ravenna.alcnetworx.com/technology/open-
technology-standards/aes67-x192.html

The draft is a normative reference for the recently published AES67 
standard and is referenced by 
https://ietf.org/doc/draft-ietf-avtcore-idms/ which is now in the RFC 
editor queue waiting for this document.

There was an SDP directorate review and comments were addressed. 


Personnel

Document Shepherd is Roni Even and the responsible AD is Alissa Cooper.