Indicating User Agent Capabilities in the Session Initiation Protocol (SIP)
RFC 3840

Approval announcement
Draft of message to be sent after approval:

From: The IESG <>
To: IETF-Announce <>
Cc: Internet Architecture Board <>,
    RFC Editor <>, 
    sip mailing list <>, 
    sip chair <>
Subject: Protocol Action: 'Indicating User Agent Capabilities in 
         the Session Initiation Protocol (SIP)' to Proposed Standard 

The IESG has approved the following document:

- 'Indicating User Agent Capabilities in the Session Initiation Protocol 
   (SIP) '
   <draft-ietf-sip-callee-caps-04.txt> as a Proposed Standard

This document is the product of the Session Initiation Protocol Working 

The IESG contact persons are Allison Mankin and Jon Peterson.

A URL of this Internet-Draft is:

Technical Summary

  This specification defines mechanisms by which a Session Initiation
   Protocol (SIP) user agent can convey its capabilities and
   characteristics to other user agents and to the registrar for its
   domain. This information is conveyed as parameters of the Contact
   header field.  It may be used by a proxy for call routing. The parameter
   design is based on RFC 2506, media feature tags.  The specification
   creates a SIP tree registry parallel to the IETF tree registry from
   RFC 2506.  The syntax of the parameters is based on RFC 2533.

   Strong considerations regarding the privacy and data
   integrity of the information are discussed by the document.
Working Group Summary
   The working group took a lot of care and review developing this design.
    There was a mid-course design review from an Applications area
    standpoint that resulted in the advice to work with the RFC 2533,
    2506 approach, which has proved to be very constructive.  The WG
    supported the advancement strongly, after thorough review.
Protocol Quality
   The document was reviewed for the IESG by Allison Mankin.  The
    Applications mid-course reviews were by Patrik Faltstrom and Ted