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Shepherd writeup

As required by RFC 4858, this is the current template for the Document 
Shepherd Write-Up.

Changes are expected over time. This version is 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?

    Informational, which is reflected correctly on the 
    title page header.

    This draft is an update to RFC 4458, which is also 

   Some history on RFC type:  RFC 4458, since it registers 
   the "cause" URI parameter, probably should have been 
   standards track, but at the time of publication, RFC 3969 
   was not consistent in specifying that Standards Action 
   was required for the registration of SIP URI parameters 
   (RFC 5727 clarifies this). The minutes for the SIP WG, 
   IETF 60, show that there was consensus to progress 
   draft-jennings-sip-voicemail-uri (RFC 4458) as an 
   individual submission to Informational, which is the 
   path that RFC 4458 took. If the contents of RFC 4458 
   were to be proposed today, the document would need 
   to be standards track.

   After much discussion between the IESG, the ART AD, 
   the SIPcore and Dispatch chairs about updating   
   RFC 4458 to be standards track and progressing 
   as standards track, it was decided to leave them as is.  
   The "cause" URI parameter is not intended for general use  
   across the internet. draft-mohali-dispatch-service-number-translation  
   does not register a URI parameter; it just adds a reference  
   to an existing registration. The decision to keep these  
   documents informational is not intended to set precedent; 
   RFC 5727 remains the BCP for the SIP change process.

(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

  Relevant content can frequently be found in the abstract 
  and/or introduction of the document. If not, this may be 
  an indication that there are deficiencies in the abstract 
  or introduction.

    This specification creates a new, predefined value (380) 
    for the "cause" URI parameter, defined in RFC 4458, to 
    indicate that service number translation, in which a 
    service access number has been retargeted due to specific 
    service action, has occurred. 

 Working Group Summary

  Was the document considered in any WG, and if so, why was
  it not adopted as a work item there? Was there controversy
  about particular points that caused the WG to not adopt the

    Versions -00, -01, and -02 received feedback on the 
    Dispatch mailing list. At IETF 92, the Dispatch chairs 
    proposed to progress the draft as individual/AD sponsored, 
    and no objections were raised. 

    With the earliest drafts, there was some confusion among 
    discussion participants about which "cause" parameter was 
    being updated since SIP has both a "cause" URI parameter 
    and a "cause" header field parameter that is used with the 
    Reason header field. Which "cause" parameter the document   
    impacts is clarified in section 2.1 of the draft. 

 Document Quality

  Are there existing implementations of the protocol? Have a 
  significant number of vendors indicated their plan to 
  implement the specification? Are there any reviewers that 
  merit special mention as having done a thorough review, 
  e.g., one that resulted in important changes or a 
  conclusion that the document had no substantive issues? If 
  there was a MIB Doctor, Media Type or other expert review, 
  what was its course (briefly)? In the case of a Media Type 
  review, on what date was the request posted?

    3GPP will be rolling this update out with Release 13, 
    so there will be multiple implementations of this document.

    An expert review was not required for this document. 

    The document's Acknowledgments section thanks reviewers
    who had significant feedback.


  Who is the Document Shepherd? Who is the Responsible Area

    Document Shepherd: Jean Mahoney

    Responsible Area Director: 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 thoroughly reviewed versions -06 through -09 
    of this document. This document is ready to be forwarded
    to the IESG. 

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


(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.


(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 interested community has
discussed those issues and has indicated that it still wishes to advance
the document, detail those concerns here.

    The Document Shepherd does not have any concerns about 
    this document.

(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.

    Each author confirmed that they had no IPR to declare 
    on this draft.

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

    None filed.

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

    There is consensus that AD sponsored is the best approach for 
    progressing this document. This document received support from 
    reviewers on the Dispatch mailing list, and there have been no 
    concerns about it moving forward once it was clarified which
    "cause" parameter the document addressed. 

(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.) 


(11) Identify any ID nits the Document Shepherd has found in this
document. (See and the Internet-Drafts
Checklist). Boilerplate checks are not enough; this check needs to be

    idnits 2.14.01 was run, and no issues were found.
    The Shepherd checked the draft against
    No issues were found with the draft.

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

    No formal review was required for this update to the 
    "cause" URI parameter.  

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


(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?


(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. 


(16) Will publication of this document change the status of any existing
RFCs? Are those RFCs listed on the title page header, listed in the
abstract, and discussed in the introduction? If the RFCs are not listed
in the Abstract and Introduction, explain why, and point to the part of
the document where the relationship of this document to the other RFCs
is discussed. If this information is not in the document, explain why
the interested community considers it unnecessary.

    This document updates RFC 4458. This information is clearly 
    captured in the header, abstract, and introduction.

(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).

    The IANA Considerations section clearly identifies the 
    "SIP/SIPS URI Parameters" subregistry within the "Session 
    Initiation Protocols" registry, and shows how to modify
    the subregistry with the new reference. 

(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.

    No expert review is required for new values of the 
    "cause" parameter. 

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

    No sections of this document are written in a formal language, 
    thus no automated checks were performed.