Early Retransmit for TCP and Stream Control Transmission Protocol (SCTP)
draft-ietf-tcpm-early-rexmt-04

[Ballot comment]
I have cleared my Discuss.  The conversation with the authors has clarified that this specification is intended for experimentation without being "used in operational settings" (Mark Allman).  While I would have been happier with a brief note to this effect in the document itself, I'm not willing to hold up its publication over the issue.

[Ballot comment]
I have reluctantly cleared my Discuss on this document as this sort of issue should not hold up publication. The Discuss position achieved the objective of causing discussion within the IESG and with one of the document authors, and I am now informed that the authors will not make any change to the document.

It seems to me unfortunate that the author is unwilling to include a simple statement that would make the purpose of the document more clear with respect to its Experimental status and with respect the working group's intentions for the protocol work in the future. This would also help the implementer decide between the various choices in the document.

[Ballot discuss]
Changing to Discuss...

If this doc is to be published as "Experimental", it should include plans to monitor the effect of protocol deployment on the operation of the Internet, and plans for experiments to determine if the protocol meets the goals and requirements.

As Adrian points out, text to explain why this Experimental spec won't affect the Internet or how the effect can be monitored and a brief description of how the spec might be evaluated should be easy to write based on the authors consideration of the issues during development of the spec.

[Ballot comment]
Section 2
s/less than four/fewer than four/

I agree with the Comment about providing more description of the Experiment. For me, this is close to being a Discuss. I would like to see the scope of the Experiment, how it is isolated from the rest of the Internet (or a statement about why that is not necessary), and how the results will be evaluated. (Note that section 3.3 gives some hints.)

Given the number of options left as a "choice for the implementer" I would like to see some Experimental objectives that will help to reduce the number of implementation options in the future.

[Ballot discuss]
After discussing this issue with other members of the IESG and with one of the authors, I am "upgrading" my previous Comment to a Discuss.

RFC 2026 is clear on the purpose of Experimental RFCs: they describe experiments. I feel that to qualify as an Experimental RFC, the document should explain what the experiment is. There are good reasons for this, and perhaps the most important is to allow the IESG to evaluate the risks of releasing the experiment into the Internet.

Assuming that there is a clear vision amongst the authors for what is being undertaken here, it should not take more than a few minutes to write a paragraph for inclusion in the Introduction that scopes the experiment.

[Ballot comment]
I agree with Adrian's DISCUSS and Ralph's COMMENT about the need to better define the conditions of the experiment, criteria to assess results, and operational impact of deployment in the Internet.

[Ballot comment]
I agree with Adrian's DISCUSS and Ralph's COMMENT about the need to better divide the conditions of the experiment, criteria to assess results, and operational impact of deployment in the Internet.

[Ballot comment]
(1)

In sections 2.1 and 2.2 the text for evaluating the conditions is imprecise.  I suggest
the following edits to cover the case where one of (a) or (b) does not hold:

In 2.1

OLD
    When conditions (2.a) and (2.b) do not hold, the transport MUST NOT
    use Early Retransmit, but rather prefer the standard mechanisms,
    including Fast Retransmit and Limited Transmit.
NEW
    If either (or both) condition (2.a) or (2.b) does not hold, the transport MUST NOT
    use Early Retransmit, but rather prefer the standard mechanisms,
    including Fast Retransmit and Limited Transmit.

(There is almost certainly better wording, but hopefully this clarifies this issue.)

A similar fix is need in 2.2.

(2)

Intuitively, I understand that this algorithm should result in retransmission of outstanding
segments.  However, I could not actually find this statement anywhere.  The main audience
probably doesn't need its hand held here, but for the rest of us a clear statement would be
nice.

[Ballot comment]
I agree with the COMMENTs by Raph and Adrian about the need to better divide the conditions of the experiment, criteria to assess results, and operational impact of deployment in the Internet. It's on the verge of a DISCUSS for me as well.

[Ballot comment]
Section 2
s/less than four/fewer than four/

I agree with the Comment about providing more description of the Experiment. For me, this is close to being a Discuss. I would like to see the scope of the Experiment, how it is isolated from the rest of the Internet (or a statement about why that is not necessary), and how the results will be evaluated. (Note that section 3.3 gives some hints.)

Given the number of options left as a "choice for the implementer" I would like to see some Experimental objectives that will help to reduce the number of implementation options in the future.

[Ballot comment]
If this doc is to be published as "Experimental", it should include plans to monitor the effect of protocol deployment on the operation of the Internet, and plans for experiments to determine if the protocol meets the goals and requirements.

draft-ietf-tcpm-early-rexmt-03

  (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?

Wesley Eddy (Wesley.M.Eddy@nasa.gov) is the document shepherd.  He
has personally reviewed this version and believes it is ready 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? 

The document has had review in the TCPM working group, and prior to
that in the TSVWG from a number of experts in both WGs.  The shepherd
has no concerns about the depth or breadth of the reviews.

  (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 concerns.

  (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.

No concerns.

  (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? 

There is no opposition to this in the TCPM WG.  There is sufficient
support and reviews from approximately a dozen people across time.

  (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 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?

idnits finds 5 instances of too-long lines (in excess of 72 characters):
line 103
    250
    281
    307
    393

idnits finds 4 unused references:
AA02
LK98
Mor97
RFC3150

  (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].

Yes - there is a normative/informative split.
All normative references are RFCs.

  (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 Considerations exist and are "None".

  (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?

Not Applicable.

  (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.

From abstract:

This document proposes a new mechanism for TCP and SCTP that can be
used to recover lost segments when a connection's congestion window
is small.  The "Early Retransmit" mechanism allows the transport to
reduce, in certain special circumstances, the number of duplicate
acknowledgments required to trigger a fast retransmission.  This
allows the transport to use fast retransmit to recover segment
losses that would otherwise require a lengthy retransmission
timeout.

    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?

None.

    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?

There is limited implementation experience.  There are no MIBs or
other special items requiring expert review.