Miscellaneous Capabilities Negotiation in the Session Description Protocol (SDP)
draft-ietf-mmusic-sdp-miscellaneous-caps-07

[Ballot comment]
I think it would be helpful to add a reminder of how legacy
implementations and those that do not support the new capability
negotiations will react when they are attempted. This is probably just
a simple one line statement and a reference.

[Ballot comment]

Are these possibly missing security considerations?

- The bandwidth capability could be used as part of
a DoS if reservations are made based on bad values.
For example, if Alice gets lots of bandwidth reserved
then Bob might not be able to do stuff.

- A premium-rate number could be included in the
PSTN thingy.

[Ballot comment]
As I read the internationalization paragraph in Section 3.1.3, I find that I would appreciate an example that shows two titles for the same content, in different character sets.  Can you add such an example?

[Ballot comment]
I was able to guess at bcap and ccap, but not at icap (title), and I had to scan for a while to decode that. The 4th occurrence of "title" finally said "*media* title" capability - that helped.

Could you consider moving "media title" to the first occurrence of "title" in the doc?

IESG/Authors/WG Chairs:

IANA has reviewed draft-ietf-mmusic-sdp-miscellaneous-caps-05.  Authors should review the comments and/or questions below.  Please report any inaccuracies and respond to any questions as soon as possible.

IANA understands that, upon approval of this document, there are three actions which IANA must complete.

First, in the att-field (both session and media level) registry in the Session Description Protocol (SDP) Parameters page located at

www.iana.org/assignments/sdp-parameters

three new SDP Attributes are to be registered as follows:

Type: att-field (both session and media level)
SDP Name: bcap
Reference: [ RFC-to-be ]

Type: att-field (both session and media level)
SDP Name: ccap
Reference: [ RFC-to-be ]

Type: att-field (both session and media level)
SDP Name: icap
Reference: [ RFC-to-be ]

Second, in the SDP Capability Negotiation Option Tags registry in the Session Description Protocol (SDP) Parameters page located at

www.iana.org/assignments/sdp-parameters

three new Option Tags are to be registered as follows:

Option Tag: bcap-v0
Reference: [ RFC-to-be ]

Option Tag: ccap-v0
Reference: [ RFC-to-be ]

Option Tag: icap-v0
Reference: [ RFC-to-be ]

Third, in the SDP Capability Negotiation Configuration Parameters registry in the Session Description Protocol (SDP) Parameters page at

www.iana.org/assignments/sdp-parameters

three new SDP Capability Negotiation Configuration Parameters are to be registered as follows:

Encoding Name: b
Descriptive Name: Bandwidth
Potential Configuration Definition: [ RFC-to-be ]
Actual Configuration Definition: [ RFC-to-be ]
Latent Configuration Definition: [ RFC-to-be ]

Encoding Name: c
Descriptive Name: Connection Data
Potential Configuration Definition: [ RFC-to-be ]
Actual Configuration Definition: [ RFC-to-be ]
Latent Configuration Definition: [ RFC-to-be ]

Encoding Name: i
Descriptive Name: Title
Potential Configuration Definition: [ RFC-to-be ]
Actual Configuration Definition: [ RFC-to-be ]
Latent Configuration Definition: [ RFC-to-be ]

IANA understands that these three actions are the only ones that need to be completed upon approval.

Note:  The actions requested in this document will not be completed until the document has been approved for publication as an RFC. This message is only to confirm what actions will be performed.

The following Last Call announcement was sent out:

From: The IESG
To: IETF-Announce
CC:
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (Miscellaneous Capabilities Negotiation in the Session Description Protocol (SDP)) to Proposed Standard


The IESG has received a request from the Multiparty Multimedia Session
Control WG (mmusic) to consider the following document:
- 'Miscellaneous Capabilities Negotiation in the Session Description
  Protocol (SDP)'
  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 2013-06-04. 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


  SDP has been extended with a capability negotiation mechanism
  framework that allows the endpoints to negotiate transport protocols
  and attributes.  This framework has been extended with a media
  capabilities negotiation mechanism that allows endpoints to negotiate
  additional media-related capabilities.  This negotiation is embedded
  into the widely-used SDP offer/answer procedures.

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




The file can be obtained via
http://datatracker.ietf.org/doc/draft-ietf-mmusic-sdp-miscellaneous-caps/

IESG discussion can be tracked via
http://datatracker.ietf.org/doc/draft-ietf-mmusic-sdp-miscellaneous-caps/ballot/


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

/(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:/

/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./

/Working Group Summary:/

/Was there anything in WG process that is worth noting? For example, was
there controversy about particular points or were there decisions where
the consensus was particularly rough?/

/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?/

/Personnel:/

/Who is the Document Shepherd? Who is the Responsible Area Director?

/

*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

http://www.ietf.org/mail-archive/web/mmusic/current/msg10471.html
http://www.ietf.org/mail-archive/web/mmusic/current/msg10573.html

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
http://www.ietf.org/mail-archive/web/mmusic/current/msg10962.html 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.


*Personn**el*/
/


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
IESG./

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
place./

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
disclosures./

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
point.

/(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 http://www.ietf.org/tools/idnits/ and the Internet-Drafts
Checklist). Boilerplate checks are not enough; this check needs to be
thorough./

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
updating).

/(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?/

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?/

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.