Hello, I have reviewed this document as part of the Operational directorate's ongoing effort to review all IETF documents being processed by the IESG.  These comments were written with the intent of improving the operational aspects of the IETF drafts. Comments that are not addressed in last call may be included in AD reviews during the IESG review.  Document editors and WG chairs should treat these comments just like any other last call comments. This document is for the Informational Track. This document describes some existing and proposed properties and relationships among RTP sources, and defines common terminology for discussing protocol entities and their relationships. The aim of this document is to clarify any confusion that may be prevalent due to inconsistent usage by multiple technologies and protocols that are making use of RTP. The document is well written. The nits tool has found the following: == Outdated reference: A later version (-08) exists of draft-ietf-avtcore-rtp-multi-stream-07 == Outdated reference: A later version (-10) exists of draft-ietf-avtcore-rtp-topologies-update-08 Unfortunately, I have not had time to make an in depth review of this document,  However, I have made a brief review of the document and have found no issues. Thank you kindly, Menachem