Mechanism to Indicate Support of Features and Capabilities in the Session Initiation Protocol (SIP)

Approval announcement
Draft of message to be sent after approval:

From: The IESG <>
To: IETF-Announce <>
Cc: RFC Editor <>,
    sipcore mailing list <>,
    sipcore chair <>
Subject: Protocol Action: 'Mechanism to indicate support of features and capabilities in the Session Initiation Protocol (SIP)' to Proposed Standard (draft-ietf-sipcore-proxy-feature-11.txt)

The IESG has approved the following document:
- 'Mechanism to indicate support of features and capabilities in the
   Session Initiation Protocol (SIP)'
  (draft-ietf-sipcore-proxy-feature-11.txt) as Proposed Standard

This document is the product of the Session Initiation Protocol Core
Working Group.

The IESG contact persons are Robert Sparks and Gonzalo Camarillo.

A URL of this Internet Draft is:

Technical Summary

    This specification defines a new SIP header field, Feature-Caps, to
    convey feature capability indicators, which are used by SIP entities
    not represented by the URI of the Contact header field to indicate
    support of features and capabilities, where media feature tags cannot
    be used to indicate the support.

    This specification also defines feature capability indicators, and
    creates a new IANA registry, "Proxy-Feature Feature Capability
    Indicator Trees", for registering feature capability indicators.

Working Group Summary

  This document was driven by, and appears to be of interest
  primarily to the IMS community. However the resulting mechanism
  is of general applicability.

Document Quality

      There are implementations of this document.
      3GPP IMS has a dependency on this document. It will be
      incorporated by reference in an upcoming version of IMS,
      and will thus eventually be implemented widely.
      The document shepherd has been a reviewer and critic
      of this document, and promoted significant changes in
      the contemplated mechanism.
      Shida Shubert provided an in depth WGLC review.


      Paul Kyzivat is the document shepherd. Robert Sparks is the responsible area director.