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?

Informational. 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 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?


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

Technical Summary

The document describes several Network Address Translator (NAT) traversal techniques that were considered to be used for establishing the RTP media flows controlled by the Real-time Streaming Protocol (RTSP). Each technique includes a description on how it would be used, the security implications of using it and any other deployment considerations it has. There are also discussions on how NAT traversal techniques relate to firewalls and how each technique can be applied in different use cases. These findings were used when selecting the NAT traversal for RTSP 2.0, which is specified in a separate document.

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 decided to investigate different approaches to RTSP NAT traversal before chosing one, and as a result, the initial WG version of this document appeared 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, but a WGLC was issued in the latter part of 2012. The WGLC concluded that the (at the time current) version of the document was partially based on now obsolete NAT-related RFCs and considerations and as a result the authors updated the document to better reflect current RFCs and recommendations in the area. A WGLC was issued on this updated document in May 2013 on this document with no major comments received (2 people are known to have actively reviewed the latest versions). 

Document Quality

The document does not specify any particular protocol but is rather an investigation into possible protocol choices and as such there are no specific considerations around implementations, MIB, media type, etc. reviews. The document quality is good from both a technical and readability point of view.


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 (-10, -12 and -13) as well as the originally WGLC'ed version of the document (-05) in detail. As noted above, the original version had some issues what have all been addressed in the current version.

(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. 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?

Both authors have confirmed they are not aware of any IPR to be declared.

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

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, 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 document conclusion is aligned with the general NAT traversal strategy in the MMUSIC WG (namely to use ICE).

(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. As noted by ID nits check, the document contains a reference to the now obsolete RFC 3489, however the reference is informational and fully intentional.

(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 new protocols or extensions and hence the above review criteria do not apply.

(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 IANA considerations section complies with above (note: IANA considerations do not apply to this document, but the section is still provided).

(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 no formal language in the document and hence no such reviews have been performed.