The Session Initiation Protocol (SIP) Referred-By Mechanism
RFC 3892

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 SIP Referred-By Mechanism' to 
         Proposed Standard 

The IESG has approved the following document:

- 'The SIP Referred-By Mechanism '
   <draft-ietf-sip-referredby-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

   The SIP REFER method provides a mechanism where one party (the
   referrer) gives a second party (the referee) an arbitrary URI to
   reference.  If that URI is a SIP URI, the referee will send a SIP
   request, often an INVITE, to that URI (the refer target).  This
   document extends the REFER method allowing the referrer to provide
   information about the REFER request to the refer target using the
   referee as an intermediary.  This information includes the identity
   of the referrer and the URI to which the referrer referred.  The
   mechanism utilizes S/MIME to help protect this information from a
   malicious intermediary.  This protection is optional, but a recipient
   may refuse to accept a request unless it is present.

   The REFER method is specified in RFC 3515, which describes a general
    set of security considerations in addition to those particular to 

Working Group Summary

   The Working Group strongly supported the advancement of Referred-By,
    once it was split out of the REFER document into the present design.
Protocol Quality
  There was a large amount of working group review of Referred-by, which
   resulted in its being split out of the original REFER method document
   and the development of this mechanism and the Authentication ID Body
   (under review at the same time) on which it depends.  There were no 
   dissenting comments during WG Last Call or IETF Last Call.  The
  document was reviewed for the IESG by Allison Mankin.