A Survey of Lower-than-Best-Effort Transport Protocols
draft-ietf-ledbat-survey-07

[Ballot discuss]
The Gen-ART Review by Elwyn Davies on 17-Mar-2011 raises a question
  that deserves a response.  The review can be found at:
 
  http://www.ietf.org/mail-archive/web/gen-art/current/msg06196.html

[Ballot comment]
I liked this document a lot, thanks for writing it.

The only thing that I would change is to talk a little bit about deployability aspects of the various proposals. As it stands, the document makes statements like this:

  ... the only exception that NF-TCP-capable routers must
  be able to somehow distinguish NF-TCP traffic from other TCP traffic.

which obviously is a major issue. What changes, routers, hosts, protocol numbers, firewalls?

[Ballot discuss]
I think this is a fine document, but I am a little surprised that
Section 9 is empty and that the security aspects of the protocols
surveyed are not also discussed. I am holding this Discuss so that
I can verify that the Security ADs are comfortable with this point
during our conference call. I will then clear my Discuss, and let
them carry a Discuss if they think it is necessary.

No action is required by the authors at this time.

[Ballot discuss]
The Gen-ART Review by Elwyn Davies on 17-Mar-2011 raises a question
  that deserves a response.  The review can be found at:
 
  http://www.ietf.org/mail-archive/web/gen-art/current/msg06196.html

State changed to In Last Call from Last Call Requested.

The following Last Call Announcement was sent out:

From: The IESG <iesg-secretary@ietf.org>
To: IETF-Announce <ietf-announce@ietf.org>
CC: <ledbat@ietf.org>
Reply-To: ietf@ietf.org
Subject: Last Call: <draft-ietf-ledbat-survey-05.txt> (A Survey of Lower-than-Best-Effort Transport Protocols) to Informational RFC


The IESG has received a request from the Low Extra Delay Background
Transport WG (ledbat) to consider the following document:
- 'A Survey of Lower-than-Best-Effort Transport Protocols'
  <draft-ietf-ledbat-survey-05.txt> as an Informational 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 2011-03-24. 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.

The file can be obtained via
http://datatracker.ietf.org/doc/draft-ietf-ledbat-survey/

IESG discussion can be tracked via
http://datatracker.ietf.org/doc/draft-ietf-ledbat-survey/

(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?

Rolf Winter (rolf.winter@neclab.eu) is the Document Shepherd. The shepherd has read the latest version and reviewed earlier versions and believes the current version is ready 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?

Initially, the document had received little reviews. The chairs insisted on additional reviews by at least three active participants of the group which were found and did thorough reviews. All comments of these reviewers have been addressed by the latest version as confirmed by all reviewers.

(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 is a survey of existing work related to LEDBAT. As such there is no critical bit in the document that needs further investigations. The survey has received reviews from people that are well familiar with the work in the field.

(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.

(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 received a lot of silence but, again, the document is not very
controversial and merely surveys related work. A number of people, other than
the authors and reviewers, have however expressed that they find the document
very useful. A last call has not produced additional comments. This is enough
indication to declare consensus and it is assumed that the WG feels very comfortable
with the draft.

(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.)

Not at all.

(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 tool produced no errors or warnings.

(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].

As this is a survey, the draft contains no normative references.

(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?

No requests to IANA are made.

(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?

No such sections exist.

(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.

This document provides a survey of transport protocols which are
designed to have a smaller bandwidth and/or delay impact on standard
TCP than standard TCP itself when they share a bottleneck with it.
Such protocols could be used for delay-insensitive "background"
traffic, as they provide what is sometimes called a "less than" (or
"lower than") best-effort service.

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?

This document is a product of the LEDBAT WG. It has received reviews from
various WG participants. There were no controversies in the Last Call of
the document and the WG feels the document is ready for publication.

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?

The algorithm that triggered this survey, which is still being worked on but
nears completion, is implemented by BitTorrent Inc. Special thanks to
Mirja Kühlewind, Wesley Eddy and Mayutan Arumaithurai for their thorough
reviews of the document.