Subject: [AVT] Publication request for draft-ietf-avt-rapid-acquisition-for-rtp

From: "DRAGE, Keith (Keith)" <[email-masked]>
Date: Thu, 29 Jul 2010 20:48:24 +0200

I have just requested publication for this draft.

The document shepherd writeup follows.

regards

Keith

----------------------------------------------------

Shepherd writeup for draft-ietf-avt-rapid-acquisition-for-rtp-11 as 
proposed standard.

  (1.a) Who is the Document Shepherd for this document? Has the
        Document Shepherd personally reviewed this version of the 
        document and, in particular, does he or she believe this 
        version is ready for forwarding to the IESG for publication? 

Keith Drage is the document shepherd for this document.

The document has been reviewed and is ready for forwarding to IESG for 
publication.

Document history:

There were two predecessor drafts to the WG drafts in 

-	draft-versteeg-avt-rapid-synchronization-for-rtp-00 was 
submitted 7th July 2008 and expired 8th January 2009;
-	draft-versteeg-avt-rapid-synchronization-for-rtp-01 was 
submitted 3rd November 2008 and expired 7th May 2009;
-	draft-versteeg-avt-rapid-synchronization-for-rtp-02 was 
submitted 9th March 2009 and expired 10th September 2009;
-	draft-versteeg-avt-rapid-synchronization-for-rtp-03 was 
submitted 16th April 2009 and expired 18th October 2009;
-	draft-levin-avt-rtcp-burst-00 was submitted 27th October 2008 
and expired 30th April 2009;

Resulting from a breakout session in IETF 73 the parties decided to go 
offline and bring a single proposal which was progressed in the WG as 
follows:

-	draft-ietf-avt-rapid-acquisition-for-rtp-00 was submitted 12th 
May 2009 and expired 13th November 2009;
-	draft-ietf-avt-rapid-acquisition-for-rtp-01 was submitted 16th 
June 2009 and expired 18th December 2009;
-	draft-ietf-avt-rapid-acquisition-for-rtp-02 was submitted 25th 
August 2009 and expired 26th February 2010;
-	draft-ietf-avt-rapid-acquisition-for-rtp-03 was submitted 4th 
September 2009 and expired 8th March 2010;
-	draft-ietf-avt-rapid-acquisition-for-rtp-04 was submitted 8th 
October 2009 and expired 11th April 2010;
-	draft-ietf-avt-rapid-acquisition-for-rtp-05 was submitted 16th 
November 2009 and expired 20th May 2010;
-	draft-ietf-avt-rapid-acquisition-for-rtp-06 was submitted 4th 
February 2010 and expires 8th August 2010;
-	draft-ietf-avt-rapid-acquisition-for-rtp-07 was submitted 18th 
February 2010 and expires 22nd August 2010;
-	draft-ietf-avt-rapid-acquisition-for-rtp-08 was submitted 8th 
March 2010 and expires 9th September 2010;
-	draft-ietf-avt-rapid-acquisition-for-rtp-09 was submitted 26th 
April 2010 and expires 28th October 2010;
-	draft-ietf-avt-rapid-acquisition-for-rtp-10 was submitted 29th 
May 2010 and expires 30th November 2010;
-	draft-ietf-avt-rapid-acquisition-for-rtp-11 was submitted 9th 
July 2010 and expires 10th January 2010;

As a result of the discussion of this draft, the following issues have 
been split out into separate documents:
-	draft-begen-avt-rtcp-port-for-ssm
-	draft-ietf-avt-rtp-cnames
-	draft-ietf-avt-ports-for-ucast-mcast-rtp
There is also specific work related to MPEG2TS preambles for rapid 
acquisition for which a solution is still under discussion in the 
working group.

Working group last calls were held on the document as follows:

-	22nd November 2009 on -05 version to complete 23rd December 2009. 
Reviews were received from Colin Perkins.
-	5th May 2010 on -09 version to complete 26th May 2010. Reviews 
were received from Dan Wing, Roni Even, Keith Drage, Colin Perkins.

Magnus Westerlund has also performed an extensive review of the 
document.

  (1.b) Has the document had adequate review both from key WG members 
        and from key non-WG members? Does the Document Shepherd have 
        any concerns about the depth or breadth of the reviews that 
        have been performed?  

Apart from two working group last calls, the document has been reviewed in 
depth by a number of members of the WG. 

  (1.c) Does the Document Shepherd have concerns that the document 
        needs more review from a particular or broader perspective, 
        e.g., security, operational complexity, someone familiar with 
        AAA, internationalization or XML? 

The document does not need specific wider review. The appropriate expertise has 
existed within the AVT WG.

  (1.d) Does the Document Shepherd have any specific concerns or 
        issues 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. Has an IPR disclosure related to this document 
        been filed? If so, please include a reference to the 
        disclosure and summarize the WG discussion and conclusion on 
        this issue. 

There are multiple IPR disclosures in respect of the draft. After one member of 
the WG expressed concern, these were explicitly brought to the attention of the 
working group to see if there were other concerns. There were none.

  (1.e) 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 working group consensus. It has been widely worked on by a 
significant number of people within the working group.

  (1.f) 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 
        entered into the ID Tracker.) 

No appeals have been threatened.

  (1.g) Has the Document Shepherd personally verified that the 
        document satisfies all ID nits? (See the Internet-Drafts Checklist 
        and http://tools.ietf.org/tools/idnits/). Boilerplate checks are 
        not enough; this check needs to be thorough. Has the document 
        met all formal review criteria it needs to, such as the MIB 
        Doctor, media type and URI type reviews? 

The document passes ID NITs. The document has been thoroughly reviewed for 
editorial consistency by the document shepherd. Additionally, RFC 2119 language 
has been checked (and as part of this check a number of the requirements 
rewritten) and a number of SHOULD statements revised. 

There is one area of the document where RECOMMENDED has been used in section 
6.2. This has been extensively discussed and has been considered to be the best 
compromise wording to reflect differing opinions on what the strength of this 
requirement should be.

  (1.h) Has the document split its references into normative and 
        informative? 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 
        strategy for their completion? Are there normative references 
        that are downward references, as described in [RFC3967]? If 
        so, list these downward references to support the Area 
        Director in the Last Call procedure for them [RFC3967]. 

The document has split its references into normative and informative references.
The normative references have been assessed by the document shepherd and are 
considered to be normative references. There are no downward references (all 
the normative references are proposed standard).

  (1.i) Has the Document Shepherd verified that the document IANA 
        consideration section exists and is consistent with the body 
        of the document? If the document specifies protocol 
        extensions, are reservations requested in appropriate IANA 
        registries? Are the IANA registries clearly identified? If 
        the document creates a new registry, does it define the 
        proposed initial contents of the registry and an allocation 
        procedure for future registrations? Does it suggest a 
        reasonable name for the new registry? See [RFC5226]. If the 
        document describes an Expert Review process has Shepherd 
        conferred with the Responsible Area Director so that the IESG 
        can appoint the needed Expert during the IESG Evaluation? 

The document does contain an IANA considerations section, and this is 
consistent with the body of the document. The proposals for existing registries 
and new registries have been checked for consistency with the existing 
registration material.

  (1.j) Has the Document Shepherd verified that sections of the 
        document that are written in a formal language, such as XML 
        code, BNF rules, MIB definitions, etc., validate correctly in 
        an automated checker? 

The document contains one small portion of ABNF in section 8.1. This has been 
verified visually to be conformant.

  (1.k) 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? 

Technical summary.

When an RTP receiver joins a multicast session, it may need to acquire 
and parse certain Reference Information before it can process any data 
sent in the multicast session.  Depending on the join time, length of 
the Reference Information repetition (or appearance) interval, size of 
the Reference Information as well as the application and transport 
properties, the time lag before an RTP receiver can usefully consume 
the multicast data, which we refer to as the Acquisition Delay, varies 
and can be large.  This is an undesirable phenomenon for receivers that 
frequently switch among different multicast sessions, such as video 
broadcasts.

In this document, we describe a method using the existing RTP and RTCP 
protocol machinery that reduces the acquisition delay.  In this method, 
an auxiliary unicast RTP session carrying the Reference Information to 
the receiver precedes/accompanies the multicast stream.  This unicast 
RTP flow can be transmitted at a faster than natural bitrate to further 
accelerate the acquisition.  The motivating use case for this 
capability is multicast applications that carry real-time compressed 
audio and video.  However, the proposed method can also be used in 
other types of multicast applications where the acquisition delay is 
long enough to be a problem.

Working group summary

The document is a product of the AVT working group. The document has 
working group consensus.

Document quality

It is understood that there are existing implementations of the 
specification from a number of vendors.