The IESG has received a request from the Audio/Video Transport Core Maintenance WG (avtcore) to consider the following document: - 'RTP Clock Source Signalling' <draft-ietf-avtcore-clksrc-09.txt> as Proposed Standard The IESG plans to make a decision in the next few weeks, and solicits final comments on this action. Please send substantive comments to the ietf@ietf.org mailing lists by 2014-01-16. Exceptionally, comments may be sent to iesg@ietf.org instead. In either case, please retain the beginning of the Subject line to allow automated sorting. Abstract 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. The file can be obtained via http://datatracker.ietf.org/doc/draft-ietf-avtcore-clksrc/ IESG discussion can be tracked via http://datatracker.ietf.org/doc/draft-ietf-avtcore-clksrc/ballot/ No IPR declarations have been submitted directly on this I-D.