Received changes through RFC Editor sync (changed abstract to 'This document provides a mechanism to address issues that arise when TCP is used for traffic that exhibits periods where the sending rate is limited by the application rather than the congestion window. It provides an experimental update to TCP that allows a TCP sender to restart quickly following a rate-limited interval. This method is expected to benefit applications that send rate-limited traffic using TCP while also providing an appropriate response if congestion is experienced.

This document also evaluates the Experimental specification of TCP Congestion Window Validation (CWV) defined in RFC 2861 and concludes that RFC 2861 sought to address important issues but failed to deliver a widely used solution. This document therefore reclassifies the status of RFC 2861 from Experimental to Historic. This document obsoletes RFC 2861.')

[Ballot comment]
It does not appear that the SecDir review got a response, maybe the editor and shepherd didn't see it?
https://www.ietf.org/mail-archive/web/secdir/current/msg05697.html

He included a bunch of nits that might be helpful.

[Ballot comment]
It appears that this draft obsoletes, makes historic, and according to section 1.2, updates 2861 :-)  I guess it's okay to obsolete and make it historic in one fell swoop, but it might be worth removing "updates" from the first sentence of 1.2.

My inner pedant concurs with Barry's.

[Ballot comment]
Just a few very minor comments -- nothing that needs any discussion.

-- Section 1 --

RFC 2616 is an obsolete reference for HTTP.  The current reference is RFC 7230

  o  To incentivise the use of long-lived connections

Will you please appease my inner pedant and not say "incentivise" (which, by the way, Chrome doesn't think is a word either)?  You can take advantage of the previous bullet's use of "To remove the incentive for" by using this parallel construction: "To provide an incentive for the use of long-lived connections".

-- Section 4.2 --

  The method RECOMMENDS that the TCP SACK option [RFC2018]
  is enabled and the method defined in [RFC6675] is used to recover
  missing segments.

Even more ridiculously pedantic than the other: subjunctive mood with "recommends", please.  Make both "is" into "be".

-- Section 4.4 --

  A TCP sender implementing this specification MUST enter the non-
  validated phase when the pipeACK is less than (1/2)*cwnd.

Given that there are "MAY"s and a "SHOULD" involved in how pipeACK is computed, it seems rather odd to have a MUST that relates to its value.  You couldn't possibly determine whether an implementation was doing this "right" because there's so much variability in the value of pipeACK anyway.  No need to discuss this, but I suggest that you just do this:

NEW
  A TCP sender implementing this specification enters the non-
  validated phase when the pipeACK is less than (1/2)*cwnd.
END

(Via drafts-lastcall@iana.org): IESG/Authors/WG Chairs:

IANA has reviewed draft-ietf-tcpm-newcwv-10, which is currently in Last Call, and has the following comments:

We understand that, upon approval of this document, there are no IANA Actions that need completion.

While it is helpful for the IANA Considerations section of the document to remain in place upon publication, if the authors prefer to remove it, IANA doesn't object.

If this assessment is not accurate, please respond as soon as possible.

The following Last Call announcement was sent out:

From: The IESG <iesg-secretary@ietf.org>
To: IETF-Announce <ietf-announce@ietf.org>
CC: <tcpm@ietf.org>
Reply-To: ietf@ietf.org
Sender: <iesg-secretary@ietf.org>
Subject: Last Call: <draft-ietf-tcpm-newcwv-10.txt> (Updating TCP to support Rate-Limited Traffic) to Experimental RFC


The IESG has received a request from the TCP Maintenance and Minor
Extensions WG (tcpm) to consider the following document:
- 'Updating TCP to support Rate-Limited Traffic'
  <draft-ietf-tcpm-newcwv-10.txt> as Experimental RFC

The IESG plans to make a decision in the next few weeks, and solicits
final comments on this action. Please send substantive comments to the
ietf@ietf.org mailing lists by 2015-05-22. Exceptionally, comments may be
sent to iesg@ietf.org instead. In either case, please retain the
beginning of the Subject line to allow automated sorting.

Abstract


  This document provides a mechanism to address issues that arise when
  TCP is used to support traffic that exhibits periods where the
  sending rate is limited by the application rather than the congestion
  window.  It provides an experimental update to TCP that allows a TCP
  sender to restart quickly following a rate-limited interval.  This
  method is expected to benefit applications that send rate-limited
  traffic using TCP, while also providing an appropriate response if
  congestion is experienced.

  It also evaluates the Experimental specification of TCP Congestion
  Window Validation, CWV, defined in RFC 2861, and concludes that RFC
  2861 sought to address important issues, but failed to deliver a
  widely used solution.  This document therefore recommends that the
  status of RFC 2861 is moved from Experimental to Historic, and that
  it is replaced by the current specification.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-tcpm-newcwv/

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-tcpm-newcwv/ballot/


No IPR declarations have been submitted directly on this I-D.

As required by RFC 4858, this is the current template for the Document
Shepherd Write-Up.

Changes are expected over time. This version is dated 24 February 2012.

(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?

    The intended status of the document is Experimental.
    This document proposes an algorithm that controls congestion window
    size for rate-limited applications.
    WG concluded that Experimental is appropriate status for the document
    in order to explore its efficiency and feasibility.

(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

    This document describes an experimental proposal to allow TCP senders
    to restart data transfer quickly following an idle or less active period.
    This approach is expected to benefit applications that unable to send
    at the maximum rate permitted by the congestion window for some reasons.
    As a result, it aims to provide incentives for long-lived connections and
    to remove ad-hoc tweaks in some applications that try to maintain a large
    cwnd for future data transmissions.
    The approach can be viewed as an updated version of RFC2861 and it obsoletes
    RFC2861.

Working Group Summary

    The draft has been discussed for around 4 years. There has been explicit support
    for the draft since the beginning. Main discussion points were some detailed
    mechanisms in the logic that are related to estimating path capacity and
    preserving congestion window size during applications are idle or less active.
    The initial intended status of the draft was PS, but it has been changed to
    Experimental as a result of the discussions.
    Linux kernel has the codes which address the same issue. Their algorithms
    are slightly different from the document. There had been discussions between
    the linux kernel implementers and the document authors; however, they haven't
    reached the consensus to replace the existing kernel codes until more solid
    evidences are found.
    The WG's conclusion is to publish the draft as an experimental and explore
    its efficiency and feasibility of this approach.

Document Quality

    The document has been reviewed and discussed by multiple participants in the WG.
    Some discussions points raised by reviewers are listed in Section 9.1.
    The patches to FreeBSD and Linux kernel have been made by the efforts from the
    authors and other group.

Personnel

    Yoshifumi Nishida is the Document Shepherd for this document.
    The Responsible Area Director is Martin Stiemerling


(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 document and suggested some editorial chages.
    I concluded it is ready to be published.
   
(4) Does the document Shepherd have any concerns about the depth or
breadth of the reviews that have been performed? 

    I have no concern about it.

(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.

    There is no need for another reviews.

(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 don't have specific concern on this 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.

    Yes. Each author has confirmed.

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

    No.

(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 been mature during four-years discussions and is supported well.
    We have seen various positive feedbacks in the WG meetings and the ML.
    I believe the consensus is solid and clear.

(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.)

    No one has indicated discontent.

(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.
 
    No issue was found by idnits 2.13.02

(12) Describe how the document meets any required formal review
criteria, such as the MIB Doctor, media type, and URI type reviews.

    No formal review is required for this document.

(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?

    No.

(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.
 
    No.

(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 will obsolete RFC2861 and it is listed in the header and the abstract, also discussed in the following sections.

(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).

    There are no IANA considerations for the document.

(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.

    None

(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.

    The document contains no formal language.

As required by RFC 4858, this is the current template for the Document
Shepherd Write-Up.

Changes are expected over time. This version is dated 24 February 2012.

(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?

    The intended status of the document is Experimental.
    This document proposes an algorithm that controls congestion window
    size for rate-limited applications.
    WG concluded that Experimental is appropriate status for the document
    in order to explore its efficiency and feasibility.

(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

    This document describes an experimental proposal to allow TCP senders
    to restart data transfer quickly following an idle or less active period.
    This approach is expected to benefit applications that unable to send
    at the maximum rate permitted by the congestion window for some reasons.
    As a result, it aims to provide incentives for long-lived connections and
    to remove ad-hoc tweaks in some applications that try to maintain a large
    cwnd for future data transmissions.
    The approach can be viewed as an updated version of RFC2861 and it obsoletes
    RFC2861.

Working Group Summary

    The draft has been discussed for around 4 years. There has been explicit support
    for the draft since the beginning. Main discussion points were some detailed
    mechanisms in the logic that are related to estimating path capacity and
    preserving congestion window size during applications are idle or less active.
    The initial intended status of the draft was PS, but it has been changed to
    Experimental as a result of the discussions.
    Linux kernel has the codes which address the same issue. Their algorithms
    are slightly different from the document. There had been discussions between
    the linux kernel implementers and the document authors; however, they haven't
    reached the consensus to replace the existing kernel codes until more solid
    evidences are found.
    The WG's conclusion is to publish the draft as an experimental and explore
    its efficiency and feasibility of this approach.

Document Quality

    The document has been reviewed and discussed by multiple participants in the WG.
    Some discussions points raised by reviewers are listed in Section 9.1.
    The patches to FreeBSD and Linux kernel have been made by the efforts from the
    authors and other group.

Personnel

    Yoshifumi Nishida is the Document Shepherd for this document.
    The Responsible Area Director is Martin Stiemerling


(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 document and suggested some editorial chages.
    I concluded it is ready to be published.
   
(4) Does the document Shepherd have any concerns about the depth or
breadth of the reviews that have been performed? 

    I have no concern about it.

(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.

    There is no need for another reviews.

(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 don't have specific concern on this 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.

    Yes. Each author has confirmed.

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

    No.

(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 been mature during four-years discussions and is supported well.
    We have seen various positive feedbacks in the WG meetings and the ML.
    I believe the consensus is solid and clear.

(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.)

    No one has indicated discontent.

(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.
 
    No issue was found by idnits 2.13.02

(12) Describe how the document meets any required formal review
criteria, such as the MIB Doctor, media type, and URI type reviews.

    No formal review is required for this document.

(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?

    No.

(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.
 
    No.

(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 will obsolete RFC2861 and it is listed in the header and the abstract, also discussed in the following sections.

(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).

    There are no IANA considerations for the document.

(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.

    None

(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.

    The document contains no formal language.