Explicit Subscriptions for the REFER Method
RFC 7614

Approval announcement
Draft of message to be sent after approval:

From: The IESG <iesg-secretary@ietf.org>
To: IETF-Announce <ietf-announce@ietf.org>
Cc: RFC Editor <rfc-editor@rfc-editor.org>,
    sipcore mailing list <sipcore@ietf.org>,
    sipcore chair <sipcore-chairs@tools.ietf.org>
Subject: Protocol Action: 'Explicit Subscriptions for the REFER Method' to Proposed Standard (draft-ietf-sipcore-refer-explicit-subscription-03.txt)

The IESG has approved the following document:
- 'Explicit Subscriptions for the REFER Method'
  (draft-ietf-sipcore-refer-explicit-subscription-03.txt) as Proposed
Standard

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

The IESG contact persons are Barry Leiba, Ben Campbell and Alissa Cooper.

A URL of this Internet Draft is:
https://datatracker.ietf.org/doc/draft-ietf-sipcore-refer-explicit-subscription/


Technical Summary

  The Session Initiation Protocol (SIP) REFER request, as defined by
  RFC3515, triggers an implicit SIP-Specific Event Notification
  framework subscription.  Conflating the start of the subscription
  with handling the REFER request makes negotiating SUBSCRIBE
  extensions impossible, and complicates avoiding SIP dialog sharing.
  This document defines extensions to REFER to prevent the implicit
  subscription and, if desired, replace it with an explicit one.

Working Group Summary

  There was some controversy and difficulty in reaching agreement on this draft.
  Before work on this draft and the companion draft (draft-ietf-sipcore-refer-
  clarifications) commenced, some (notably 3GPP) made attempts to use existing
  mechanisms (RFC4488) to avoid the need for GRUUs. That mechanism as insufficient
  on its own, and so was enhanced with particular conventions. There was a desire
  to maintain compatibility with that work. This led to careful word smithing.
  That has been discussed at length within the WG. The results are now acceptable
  to all parties.

Document Quality

  The shepherd is not aware of any implementations yet. 
  It is the shepherd's understanding that 3GPP release 12 has a reference,
  indicating that implementations can be expected. 

  This document has been thoroughly reviewed and discussed. Everyone
  that had something to say has aired it. 

Personnel

  The document shepherd is Paul Kyzivat.
  The area director is Ben Campbell.