Shepherd writeup

/(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?/

Proposed Standard. The title page notes the document as 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*

SDP has been extended with a capability negotiation mechanism based on
SDP Offer/Answer, which allows endpoints to negotiate transport
protocols, attributes as well additional media-related capabilities.

This document extends the SDP capability negotiation framework to allow
endpoints to negotiate three additional SDP capabilities. In particular,
this document provides a mechanism to negotiate bandwidth ('b=' line),
connection data ('c=' line), and titles ('i=' line for each session or
media) in SDP.

*Working Group Summary*/

The document was adopted as a WG item in March 2012 and is an external
and long-standing dependency for 3GPP. The mechanisms in the document
are fairly straightforward and did not receive a lot of discussion in
the WG subsequently, and a WGLC was issued on the -02 version of the
draft in October 2012. There were no major comments received but a chair
review let to minor updates in the document resulting in the -04 version
in March 2013. At this point, several people noted lack of clarity wrt
potential overlap with ICE (RFC 5245) resulting in a somewhat
controversial debate on the mailing list about what the WG had agreed to
work on and timeliness of feedback on documents that had already been
through WGLC. See threads in

The chairs and document authors have subsequently worked to address the
concerns. While there has been limited explicit feedback on the current
wording, we have requested feedback several times, and lastly in which
resulted in no further comments received. Consequently, we believe all
concerns have been addressed at this point.

*Document Quality*/

There are currently no known implementations of the draft, however the
draft is a dependency for 3GPP, so future implementations are expected.

Earlier versions of the draft have been reviewed by a couple of WG
participants and the document shepherd has reviewed the last several
versions in detail. As noted above, the connection data capability part
of the document has received detailed feedback more recently as well.
The major contributors to these as well as earlier discussions are
listed in the Acknowledgements section of the document.


Document Shepherd: Flemming Andreasen
Responsible AD: Gonzalo Camarillo

/(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

The document shepherd has performed a detailed review of -02 and -03.
Subsequent changes in -04 and -05 have been reviewed as well.

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

There has been several reviews of the document from various
knowledgeable people and as such there are no concerns.

/(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

No such review is required.

/(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./

The document shepheard does not have any specific concerns or issues
with the document.

As noted above, there was some (late) discussion around potential
overlap with ICE (RFC 5245) which resulted in wording updates to the
document. We believe this has resolved the issue, however despite
repeated prodding, we have not received an explicit acknowledgement from
some of the previously most vocal participants in that discussion.

/(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?/

The authors have confirmed that they are not aware of any IPR.

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

There are no IPR disclosures

/(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?/

We believe there is good consensus behind the document. While there has
been limited discussion of the overall document, several people have
indicated support for it, and the connection data capability part has
received detailed discussion and review with no known concerns at this

/(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.)/

A previous version of the document caused some consternation wrt
possible overlap with ICE (refer to discussion and e-mail thread
references above). There are no known concerns with the current document.

/(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

The document has been checked by idnits and the I-D Checklist and no
nits have been found (apart from an ID reference that needs version

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

The document provides extensions to SDP only and as such the necessary
review has already been done by the MMUSIC WG.

/(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?/

Not applicable

/(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./

Not applicable

/(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 WG considers it unnecessary./

No change to existing RFCs

/(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 has been reviewed and no issues found.

/(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./

There are no new IANA registries defined in the document.

/(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./

ABNF has been verified with Bill Fenner's ABNF parser - the problems
reported by the parser are not actual issues. The form " 1*10(DIGIT) "
is used for improved readability.

There is no other formal language in the document.