Comparison of Different NAT Traversal Techniques for Media Controlled by the Real-Time Streaming Protocol (RTSP)
RFC 7604

Approval announcement
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From: The IESG <>
To: IETF-Announce <>
Cc: RFC Editor <>,
    mmusic mailing list <>,
    mmusic chair <>
Subject: Document Action: 'The Comparison of Different Network Address Translator (NAT) Traversal Techniques for Media Controlled by Real-time Streaming Protocol (RTSP)' to Informational RFC (draft-ietf-mmusic-rtsp-nat-evaluation-16.txt)

The IESG has approved the following document:
- 'The Comparison of Different Network Address Translator (NAT) Traversal
   Techniques for Media Controlled by Real-time Streaming Protocol
  (draft-ietf-mmusic-rtsp-nat-evaluation-16.txt) as Informational RFC

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

The IESG contact persons are Ben Campbell and Alissa Cooper.

A URL of this Internet Draft is:

Technical Summary

The document describes several Network Address Translator (NAT) traversal techniques that were considered to be used for establishing the RTP media flows controlled by the Real-time Streaming Protocol (RTSP). Each technique includes a description on how it would be used, the security implications of using it and any other deployment considerations it has. There are also discussions on how NAT traversal techniques relate to firewalls and how each technique can be applied in different use cases. These findings were used when selecting the NAT traversal for RTSP 2.0, which is specified in a separate document.

Working Group Summary

The RTSP specification (RFC 2326 and RFC2326bis) has long suffered from lack of a standardized NAT traversal mechanism and hence there was a desire to rectify that. The WG decided to investigate different approaches to RTSP NAT traversal before chosing one, and as a result, the initial WG version of this document appeared in 2007. Since the document is a companion to RTSP 2.0, progress on the document was to some extent gated on RTSP 2.0 progress, but a WGLC was issued in the latter part of 2012. The WGLC concluded that the (at the time current) version of the document was partially based on now obsolete NAT-related RFCs and considerations and as a result the authors updated the document to better reflect current RFCs and recommendations in the area. A WGLC was issued on this updated document in May 2013 on this document with no major comments received (2 people are known to have actively reviewed the latest versions). 

Document Quality

The document does not specify any particular protocol but is rather an investigation into possible protocol choices and as such there are no specific considerations around implementations, MIB, media type, etc. reviews. The document quality is good from both a technical and readability point of view.


Flemming Andreasen is the document shepherd. Alissa Cooper is the responsible AD.