The Session Initiation Protocol (SIP) "Replaces" Header
RFC 3891

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: 'The Session Inititation Protocol 
         (SIP) 'Replaces' Header' to Proposed Standard 

The IESG has approved the following document:

- 'The Session Inititation Protocol (SIP) 'Replaces' Header '
   <draft-ietf-sip-replaces-06.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 document defines a new header for use with SIP multi-party
   applications and call control. The Replaces header is used to
   logically replace an existing SIP dialog with a new SIP dialog.  This
   primitive can be used to enable a variety of features, for example:
   "Attended Transfer" and "Call Pickup". Note that definition of these
   example features is non-normative.

   Security considerations for this Header include strong recommendation
    of use of the Authenticated Identity Body and the Referred-by mechanism
    use of it in authorization approaches.

Working Group Summary
  The working group supported advancement of this document
   because of strong support for the enabling of distributed
   call control feature development.  
Protocol Quality
   The document was reviewed for the IESG by Allison Mankin and mid-course
    security reviewing was provided by Eric Rescorla.

RFC Editor Note

Please substute for all occurences of  ->

Please replace the following sentence in Section 4:


   Likewise in a call center
   environment, each call center agent could possess credentials which
   supervisors also have access to.


    Likewise in a call center environment, supervisors could have access to
    the credentials of each call center agent.