Subject: [ippm] Publication request: draft-ietf-ippm-multimetrics-11.txt as Proposed Standard

From: Matthew J Zekauskas <[email-masked]>
Date: Thu, 30 Jul 2009 12:41:03 -0400

The IPPM Working Group would like to request "IP Performance Metrics
(IPPM) for spatial and multicast", draft-ietf-ippm-multimetrics-11.txt,
as a Proposed Standard.

The document shepherd writeup is attached.

--Matt and Henk
Document shepherd writeup for draft-ietf-ippm-multimetrics-11.txt, as required
by rfc4858, and specified in the 17-Sep-2008 version of <http://www.ietf.org/IESG/content/Doc-Writeup.html>.

    (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? 

The document shepherd is Matt Zekauskas <[email-masked]>
The document shepherd has personally reviewed this document and
believes this version is read for forwarding to the IESG for
publication.

    (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? 

I believe the document has received sufficient review from key WG
members, especially in the rev before and the two revs after WGLC.  I
don't believe there are key non-WG members that need to review the
document.  I have no concerns about the depth or breadth of reviews
for this document.

    (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? 

no.

    (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. 

I think the AD should be aware of one potential issue.  In some of the
summary statistics, this document uses means of finite delays.
This has been of some past controversy, and I believe it has been
settled for this document; the document itself has a discussion on
packet loss in section 8.1.

(My view of) the issue is this: RFC 2679 (and the framework RFC 2330)
treat lost packets as having infinite delay.  RFC 2679 specifically
avoided using means of received packet delays, and only used order
statistics.  If you only want to report one value, knowing that the
50th percentile of delay is infinite tells you the path is bad.
Knowing only that the mean is 5mS is misleading if packet loss is 80%.
(Furthermore, means imply a normal distribution, and Internet
distributions tend to be far from normal.)  However, the industry
still uses means of finite delay, and using means can be useful in
some situations, and if the mean is always reported (or at least
considered) with loss and perhaps delay histograms, you can tell when
it is meaningless.  [Al Morton has an exposition in Section 4 of his
(so far personal) draft draft-morton-ippm-reporting-metrics-06.txt.]

This document was developed with an understanding of the limitations
of the mean, and it was chosen for composition.  There are a couple other
documents in the pipeline that also have this issue.   However, I can
believe that it might get raised again in IETF last call, although it
was not in WGLC.

I know of no IPR disclosures related to this document.

    (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? 

I think WG consensus behind this document is fairly strong at this point,
although I think there has been more silence on this document than
some of the other recent ones.

    (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.

    (1.g) Has the Document Shepherd personally verified that the 
          document satisfies all ID nits? (See 
          http://www.ietf.org/ID-Checklist.html 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? 

Yes.  There are no other area formal reviews needed.

    (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]. 

References are split and appropriate.  There are no downward refs, nor
normative refs to wait for.  There is one non-normative work-in-progress
reference (to Spatial Composition of Metrics) that has a new revision number,
but the reference is still appropriate and would be referenced as a work
in progress rather than specific version number.

    (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 IANA consideration section exists, and is consistent with the
other documents from IPPM and RFC 4148, which describes the IPPM
Metrics Registry.

    (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 only section where this could apply is the IANA Considerations
section, where IANA is asked to register the metrics in the IPPM 
Metrics Registry.  The entries given are proper form with respect
to RFC 4148, which defined the registry.

    (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 

The IETF has standardized IP Performance Metrics (IPPM) for measuring
end-to-end performance between two points.  This memo defines two new
categories of metrics that extend the coverage to multiple
measurement points.  It defines spatial metrics for measuring the
performance of segments of a source to destination path, and metrics
for measuring the performance between a source and many destinations
in multiparty communications (e.g., a multicast tree).

The scope of this memo is limited to metrics using a single source
packet or stream, and observations of corresponding packets along the
path (spatial), at one or more destinations (one-to-group), or both.
Note that all the metrics defined herein are based on observations of
packets dedicated to testing, a process that is called active
measurement.  Passive measurement (for example, a spatial metric
based on the observation of user traffic) is beyond the scope of this
memo.

          Working Group Summary 

The working group input has improved this document through its
revisions, and the document itself has been uncontroversial.

          Document Quality 

I know of no current implementations that claim to implement this metric.
However, other implementers in the group have read the draft.