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?

Standards Track. The RFC type is indicated on the front page.

(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

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?


Who is the Document Shepherd? Who is the Responsible Area Director?
Technical Summary

The document defines a solution for Network Address Translation (NAT)
traversal for datagram based media streams set up and controlled with
Real-time Streaming Protocol version 2 (RTSP 2.0). It uses Interactive
Connectivity Establishment (ICE) adapted to use RTSP as a signalling
channel, defining the necessary RTSP extensions and procedures.

Working Group Summary

The RTSP specification (RFC 2326 and RFC2326bis) has long suffered
from lack of a standardized NAT traversal mechanism and hence there
was a desire to rectify that. The WG has separately investigated
different approaches to RTSP NAT and concluded that a solution
leveraging ICE was preferred. The ICE-based solution appeared
initially in the -05 WG version of this document in 2007. Since the
document is a companion to RTSP 2.0, progress on the document was to
some extent gated on RTSP 2.0 progress as well as progress on the
accompanying RTSP NAT Evaluation document, but a WGLC was issued on
the -14 version in the latter part of 2012. Following review comments
and updates, another WGLC was issued on -15 in the middle of 2013 with
no major comments received. A few minor updates have been done since
then as a result of active reviews from 2 people while waiting for
RTSP 2.0 and the accompanying RTSP NAT Evalution documents to

Document Quality The document has been reviewed in detail several
times after WGLC (incl. by one of the ICE-bis authors) and in
preparation for the publication request and the authors have made
various minor updates as a result of those. The document is considered
to be of good quality at this point.

There are no known implementations of the current specification,
however a prototype implementation of an earlier version of the spec
was done a while back.

There are no new media types, MIBs, etc. and hence no such reviews


Flemming Andreasen is the document shepherd.

Gonazalo Camarillo is the responsible AD.

(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.

I have reviewed the latest versions (-17, -18, -19, and -20) of the
document in detail and my MMUSIC co-chair reviewed the prior versions
(-14, -15, and -16) in detail.

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

The document has seen limited review and active contributions from the
WG for a while, however, besides the authors, 2 people have reviewed
recent version(s) in detail and other people have reviewed earlier
versions. One of the reviewers is Ari Keranen who is a known ICE
expert, and as such there is no concern with the depth of the reviews.
While the breadth of the reviews could be better, there are no
specific 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.

(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?

All authors have confirmed they are not aware of any IPR to be

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

There is no such IPR disclosure.

(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?

The document has seen limited active participation by the WG,
especially for the more recent versions, however we believe there is
good consensus behind the document for two reasons: - We have not seen
(or heard) anybody express any concerns with the document - The NAT
traversal solution leverages ICE, which is the standards-based IETF
mechanism for doing so, and furthermore a product of the MMUSIC group.

(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.)

There are no known concerns

(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 thorough.

There are no nits at this point. A check with ID nits will generate 2
warnings and 2 comments, however these are all false positives (as
verified by the document shepherd as well as the authors). In
particular, the reference to the obsolete RFC 3489 is fully

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

The document does not specify any extensions that would require any
such formal reviews.

(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?

There are no such normative references.

(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 are no downward normative references.

(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.

The document does not change the status of any 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 document specifies several extensions which are all covered by the
IANA considerations with existing registries. There are no new IANA
registries required.

(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.

Not applicable.

(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.

There is ABNF in the document which has been checked by use of Bill
Fenner's ABNF Parser.