Clarifications for the Use of REFER with RFC 6665
draft-ietf-sipcore-refer-clarifications-04

[Ballot comment]
A couple of nits, but I'm a Yes.

3GPP capitalizes "3GPP", don't they? It would be nice to match their usage.

It might be nice to provide a pointer of some sort, so that people who work on the periphery of 3GPP can figure out if they are involved enough to care about "the 3GPP environment".

In this text:

4.  Dialog reuse is prohibited

  If a peer in an existing dialog has provided a GRUU as its Contact,
  sending a REFER that might result in an additional dialog usage
  within that dialog is prohibited.  This is a direct consequence of
  [RFC6665] requiring the use of GRUU, and the requirements in section
  4.5.2 of that document.
 
I found the use of "is prohibited" somewhat strange, because this section contains plenty of RFC 2119 language in close proximity. Am I reading this as saying "the 2119 language is over there"?

If so, section 4.5.2 is nearly two pages long. Is this text just pointing to

  Subscribers MUST NOT attempt to reuse dialogs whose remote target is
  a GRUU.
 
or to something else?

(Via drafts-lastcall@iana.org): IESG/Authors/WG Chairs:

IANA has reviewed draft-ietf-sipcore-refer-clarifications-04, which is currently in Last Call, and has the following comments:

We understand that, upon approval of this document, there are no IANA Actions that need completion.

While it is helpful for the IANA Considerations section of the document to remain in place upon publication, if the authors prefer to remove it, IANA doesn't object.

If this assessment is not accurate, please respond as soon as possible.

The following Last Call announcement was sent out:

From: The IESG
To: IETF-Announce
CC:
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (Clarifications for the use of REFER with RFC6665) to Proposed Standard


The IESG has received a request from the Session Initiation Protocol Core
WG (sipcore) to consider the following document:
- 'Clarifications for the use of REFER with RFC6665'
  as Proposed Standard

The IESG plans to make a decision in the next few weeks, and solicits
final comments on this action. Please send substantive comments to the
ietf@ietf.org mailing lists by 2015-06-17. Exceptionally, comments may be
sent to iesg@ietf.org instead. In either case, please retain the
beginning of the Subject line to allow automated sorting.

Abstract


  The SIP REFER method relies on the SIP-Specific Event Notification
  Framework.  That framework was revised by RFC6665.  This document
  highlights the implications of the requirement changes in RFC6665,
  and updates the definition of the REFER method, RFC3515, to clarify
  and disambiguate the impact of those changes.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-sipcore-refer-clarifications/

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-sipcore-refer-clarifications/ballot/


No IPR declarations have been submitted directly on this I-D.

This is my AD Evaluation of draft-ietf-sipcore-refer-clarifications-04.

Summary: Ready for IETF Last Call. I will kick that off together with the refer-explicit-subscriptions draft when I have finished reviewing that draft.

Comments: None.

Shepherd writeup for draft-ietf-sipcore-refer-clarifications-04:

[This is based on the template version dated 24 February 2012.]

(1) What type of RFC is being requested (BCP, Proposed Standard,
Internet Standard, Informational, Experimental, or Historic)?  Why
is this the proper type of RFC?  Is this type of RFC indicated in the
title page header?

  This document is marked as Standards Track in the title page header,
  and that seems appropriate, because it is clarifying normative behavior
  in RFC6665, that is itself standards track.

(2) The IESG approval announcement includes a Document Announcement
Write-Up. Please provide such a Document Announcement Write-Up. Recent
examples can be found in the "Action" announcements for approved
documents. The approval announcement contains the following sections:

Technical Summary

  The SIP REFER method relies on the SIP-Specific Event Notification
  Framework.  That framework was revised by RFC6665.  This document
  highlights the implications of the requirement changes in RFC6665,
  and updates the definition of the REFER method, RFC3515, to clarify
  and disambiguate the impact of those changes.

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-
  explicit-subscription) 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

  [Are there existing implementations of the protocol? Have a
  significant number of vendors indicated their plan to
  implement the specification?]

  I'm not aware of any implementations yet.
  It is my 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.

(3) Briefly describe the review of this document that was performed by
the Document Shepherd.  If this version of the document is not ready
for publication, please explain why the document is being forwarded to
the IESG.

  The shepherd was a SIPCORE chairman during the entire period while this
  document was introduced and discussed. He has followed (and participated
  in) the discussion and reviewed the document carefully.

(4) Does the document Shepherd have any concerns about the depth or
breadth of the reviews that have been performed? 

  NO.

(5) Do portions of the document need review from a particular or from
broader perspective, e.g., security, operational complexity, AAA, DNS,
DHCP, XML, or internationalization? If so, describe the review that
took place.

  NO.

(6) Describe any specific concerns or issues that the Document Shepherd
has with this document that the Responsible Area Director and/or the
IESG should be aware of? For example, perhaps he or she is uncomfortable
with certain parts of the document, or has concerns whether there really
is a need for it. In any event, if the WG has discussed those issues and
has indicated that it still wishes to advance the document, detail those
concerns here.

  NONE.

(7) Has each author confirmed that any and all appropriate IPR
disclosures required for full conformance with the provisions of BCP 78
and BCP 79 have already been filed. If not, explain why.

  YES.

(8) Has an IPR disclosure been filed that references this document?
If so, summarize any WG discussion and conclusion regarding the IPR
disclosures.

  NO.

(9) How solid is the WG consensus behind this document? Does it
represent the strong concurrence of a few individuals, with others
being silent, or does the WG as a whole understand and agree with it? 

  There is good consensus.

(10) Has anyone threatened an appeal or otherwise indicated extreme
discontent? If so, please summarise the areas of conflict in separate
email messages to the Responsible Area Director. (It should be in a
separate email because this questionnaire is publicly available.)

  NO.

(11) Identify any ID nits the Document Shepherd has found in this
document. (See http://www.ietf.org/tools/idnits/ and the Internet-Drafts
Checklist). Boilerplate checks are not enough; this check needs to be
thorough.

  The following are reported by IdNits:

  -- The draft header indicates that this document updates RFC3515, but the
    abstract doesn't seem to directly say this.  It does mention RFC3515
    though, so this could be OK.

  It is indeed OK.

  -- The document seems to lack a disclaimer for pre-RFC5378 work, but may
    have content which was first submitted before 10 November 2008.  If you
    have contacted all the original authors and they are all willing to grant
    the BCP78 rights to the IETF Trust, then this is fine, and you can ignore
    this comment.  If not, you may need to add the pre-RFC5378 disclaimer.
    (See the Legal Provisions document at
    http://trustee.ietf.org/license-info for more information.)

  This document has no content with such concern.

  -- Possible downref: Normative reference to a draft: ref.
    'I-D.roach-sipcore-6665-clarification'

  Only a downref because it is a draft. That document is also being submitted
  for advancement in tandem with this one.

  == Outdated reference: A later version (-02) exists of
    draft-ietf-sipcore-refer-explicit-subscription-00

  YES - needs to be updated to the eventual RFC.

(12) Describe how the document meets any required formal review
criteria, such as the MIB Doctor, media type, and URI type reviews.

N/A

(13) Have all references within this document been identified as
either normative or informative?

  YES.

(14) Are there normative references to documents that are not ready for
advancement or are otherwise in an unclear state? If such normative
references exist, what is the plan for their completion?

  NO.

(15) Are there downward normative references references (see RFC 3967)?
If so, list these downward references to support the Area Director in
the Last Call procedure.

  There is a normative reference to draft-roach-sipcore-6665-clarification'.
  The intent is that these two drafts should progress in parallel.
  It is expected that this draft won't progress until/unless that
  draft does.

(16) Will publication of this document change the status of any
existing RFCs?

  YES.

Are those RFCs listed on the title page header, listed
in the abstract, and discussed in the introduction?

  YES.

(17) Describe the Document Shepherd's review of the IANA considerations
section, especially with regard to its consistency with the body of the
document. Confirm that all protocol extensions that the document makes
are associated with the appropriate reservations in IANA registries.
Confirm that any referenced IANA registries have been clearly
identified. Confirm that newly created IANA registries include a
detailed specification of the initial contents for the registry, that
allocations procedures for future registrations are defined, and a
reasonable name for the new registry has been suggested (see RFC 5226).

  IANA considerations are empty, and appropriately so.

(18) List any new IANA registries that require Expert Review for future
allocations. Provide any public guidance that the IESG would find
useful in selecting the IANA Experts for these new registries.

  NONE.

(19) Describe reviews and automated checks performed by the Document
Shepherd to validate sections of the document written in a formal
language, such as XML code, BNF rules, MIB definitions, etc.

  N/A.