Subject: [MEDIACTRL] Draft MRB -13 Shepherd Writeup

From: Eric Burger <[email-masked]>
Date: Fri, 6 Jul 2012 11:22:31 -0400

This is what will accompany the -13, and hopefully final, draft of the MRB document. Thoughts welcome.

(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, as indicated on the title 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?
 
Personnel
  Who is the Document Shepherd? Who is the Responsible Area
  Director?
 
-----
Technical Summary
 
    The MediaCtrl work group in the IETF has proposed an architecture
    for controlling media services.  The Session Initiation Protocol
    (SIP) is used as the signaling protocol which provides many
    inherent capabilities for message routing.  A need exists for
    intelligent, application level media service selection based on
    non-static signaling properties, especially in deployment
    architectures that include 1:M and M:N combinations of Application
    Servers and Media Servers.  This document introduces a Media
    Resource Broker (MRB) entity which manages the availability of
    Media Servers and the media resource demands of Application
    Servers.  The document includes potential deployment options for an
    MRB and appropriate interfaces to Application Servers and Media
    Servers.
 
Working Group Summary
 
    The working group consensus on this document is solid.  Two
    WGLCs were held, one after the initial consensus on the
    document, and one after extensive review and implementation
    experience dictated a number of small improvements to the
    protocol and its description.
 
Personnel
    Dale Worley is the document shepherd.
    Robert Sparks 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.
 
    Line by line reading as a relative newcomer to the work group.

(4) Does the document Shepherd have any concerns about the depth or
breadth of the reviews that have been performed? 
 
    I [Dale] have no such concerns.  The only plausible concern is
    that the protocol seems to be overly complex, in that it allows
    several different modes of operation for broadly similar
    actions.  But the people involved in the draft are involved in
    practical deployments, and they have found the various
    alternatives in the protocol are necessary in various practical
    situations.

(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.
 
    See (4) above.

(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.
 
    I [Eric] have the concern that we do not properly use the xml:lang
    tag.  Review from W3C folks have highlighted the incorrect use of
    the tag.  There is a risk that a network element may take a snippet
    of a MRB protocol data unit, put it into an XML document, and
    inadvertently change the language of that XML document to the
    snippets' language.  However, we do not today see any circumstance
    where this is likely to happen.
 
    To fix this would mean changing all of the MEDIACTRL protocol
    suite, not only the MRB protocol described by this document.
    Because of this, the work group felt that keeping things consistent
    was much more important than fixing this minor issue.  Moreover,
    most of the MEDIACTRL protocols have many years of deployment
    experience in live networks.
 
    It is our estimation that changing all of the protocols to change
    only the xml:lang tag. would not see widespread deployment.  Thus,
    it would not help interoperability, as any new implementations
    would be unaware that the industry was not following such a changed
    specification.
 
    The plan to remedy this error is to finish the work we have now.
    This MRB document is the last protocol document in the MEDIACTRL
    suite.  This will enable us to close this work group.  Then we
    can charter a new work group with the task of reviewing the
    deployment experience, potentially brining the specifications
    to Internet Standard, and fix this outstanding xml:lang issue.

(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.
 
    Yes.

(8) Has an IPR disclosure been filed that references this document?
If so, summarize any WG discussion and conclusion regarding the IPR
disclosures.
 
    AT&T has filed 3 IPR disclosures regarding the predecessor draft,
    draft-boulton-mediactrl-mrb: ID # 897, ID # 898, and ID # 899.
    AT&T is listed as offering RAND licensing terms.
 
    The IPR disclosures were submitted in 2007.  The chairs solicited
    feedback from the WG twice, in 2007 and 2008.  There seems to have
    been no response to the solicitation and no further discussion of
    the IPR issues on any IETF mailing list, suggesting that no
    controversy ensued.  I would expect that any implementers who
    worried that the IPR would be burdensome would have spoken up.
 
    Neither of the chairs at the time (Eric Burger and Spencer Dawkins),
    nor two of the three authors (Chris Boulton and Lorenzo Miniero)
    work for AT&T, so there seems to be no reason to suspect undue
    influence of AT&T to promote its commercial interests.  (The third
    author, Gary Munson, does work for AT&T.)
 
    The WGLC of 7 Feb 2012 specifically mentioned the IPR disclosures,
    to provide a last opportunity for implementers to express any
    concerns over the IPR situation.  No objections were raised
    regarding IPR.

(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?  
 
    A WGLC was given on the -02 version on 15 Dec 2009.  It received no
    responses.  A final WGLC on the -12 version was given on 7 Feb 2012.
    It received no responses either.

(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.)
 
    None.

(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.
 
    None (on -12).

(12) Describe how the document meets any required formal review
criteria, such as the MIB Doctor, media type, and URI type reviews.
 
    "Registration of application/mrb-publish+xml and
    application/mrb-consumer+xml" was sent to ietf-types on 19 Jan 2012.
    Two responses were received from one person.  The comments were
    minor editorial matters which I [Dale] believe do not require
    changes to the draft.

(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?
 
     None.

(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.
 
    None.

(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.
 
    None.

(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).
 
    Confirmed.

(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 new IANA registrations, but no new IANA registries.

(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.
 
   One author (Lorenzo Miniero) checked the schemas using Eclipse
   and XML Spy, and validated the examples using a JAXB-based tool.