Hi,










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 about how SIP back-to-back User Agent can act as intermediaries in a way to avoid loss of RTCP message data (feedback & statistics) which is of course of primer importance for operations (for example, they can also change codec on the
 flight).










As the main focus of the document is to identify potential operational issues in various deployments and for some deployment the I-D goes in depth and in details. So, I tend to consider that I have nothing to add about this I-D on the operation aspects:
 it is good to go :-)










Thanks for this clear document










-éric