Hi, I have reviewed this document as part of the security directorate's ongoing effort to review all IETF documents being processed by the IESG. These comments were written with the intent of improving security requirements and considerations in IETF drafts. Comments 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. Summary: Ready to publish with a question: I question why the use of SRTP is a MAY and not a SHOULD (as detailed in the Security Considerations section). Considering PERPASS I believe this should be a SHOULD; someone should have a very good reason why they are NOT using SRTP. Details: This document defines the Real-time Transport Protocol (RTP) payload format for packetization of Opus encoded speech and audio data necessary to integrate the codec in the most compatible way. Further, it describes media type registrations for the RTP payload format. I have no other comments on this document. -derek -- Derek Atkins 617-623-3745 derek at ihtfp.com www.ihtfp.com Computer and Internet Security Consultant