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.
