An Extension to the Session Description Protocol (SDP) and Real-time Transport Protocol (RTP) for Media Loopback

Approval announcement
Draft of message to be sent after approval:

From: The IESG <>
To: IETF-Announce <>
Cc: RFC Editor <>,
    mmusic mailing list <>,
    mmusic chair <>
Subject: Protocol Action: 'An Extension to the Session Description Protocol (SDP) and Real-time Transport Protocol (RTP) for Media Loopback' to Proposed Standard (draft-ietf-mmusic-media-loopback-27.txt)

The IESG has approved the following document:
- 'An Extension to the Session Description Protocol (SDP) and Real-time
   Transport Protocol (RTP) for Media Loopback'
  (draft-ietf-mmusic-media-loopback-27.txt) as Proposed Standard

This document is the product of the Multiparty Multimedia Session Control
Working Group.

The IESG contact persons are Gonzalo Camarillo and Robert Sparks.

A URL of this Internet Draft is:

Technical Summary

This document provides extensions to the Session Description Protocol
(SDP) and the Real-time Transport Protocol (RTP) for enabling looping
of sent media. Media loopback is especially popular in ensuring the
quality of transport to the edge of a given VoIP, Real-time Text or
Video over IP service. The extension defined herein adds new SDP media
types and attributes, which enable establishment of media sessions
where the media is looped back to the transmitter. Such media sessions
will serve as monitoring and troubleshooting tools by providing the
means for measurement of more advanced VoIP, Real-time Text and Video
over IP performance metrics.

Working Group Summary

The first version of the document was available at the end of 2004.
Since that time, the working group has been discussing a number of
issues toward getting the consensus that is believed to be achieved in
version 22.

The description of a latching mechanism to traverse NATs and firewalls
was discussed and decided to be removed from the actual document in
favor of standard NAT traversal techniques such as ICE/STUN/TURN.

Document Quality

At least four implementations of this functionality are known. Four
other vendors have indicated they plan to implement it.

The document was WGLCed on version 16. Additionally, the PAYLOAD WG
also conducted a thorough review of the same 16 version. As a result of
these reviews, 34 changes were requested by, among others, Tolga
Asveren, Dan Wing, Emil Ivov, Flemming Andreasen, and Miguel A. Garcia.
These comments were subsequently introduced into versions 17 and 18. A
new WGLC was issued on version 18, bringing a new set of comments by
Flemming Andreasen, Magnus Westerlund, and Gunnar Hellstrom. These were
addressed in version 19.

At least Magnus Westerlund and Flemming Andreasen did a thorough review
of the document as part of the WGLC on version 18.

Version 18 was sent to the ietf-types mailing list for review on April
4, 2012. Bjorern Hoehrmann and Magnus Westerlund posted comments that
were addressed in version 19.


Who is the Document Shepherd? Who is the Responsible Area

Miguel A. Garcia is the Document Shepherd. Gonzalo Camarillo is the
Responsible Area Director