Tunnelling of Explicit Congestion Notification
draft-ietf-tsvwg-ecn-tunnel-10

I actually just wanted to check the revised ID that was published today to address all raised issues.
It checked out OK.
Is there anything special I need to writeup, or can you send the approved announcement?
I changed state in the datatracker to "approved announcement to be sent" with no substate.

[Ballot comment]
A few comments from Ari Keranen:

1. Introduction

  Nonetheless, the latest IPsec architecture [RFC4301] considered a
  bandwidth limit of 2 bits per packet on a covert channel made it a
  manageable risk.

Remove "made it"?

4. New ECN Tunnelling Rules

  an alternate congestion marking scheme used by a specific Diffserv
  PHB (see S.5 of [RFC3168] and [RFC4774]).

For consistency: s/S/Section/
(also in Section 7 and Appendix B1)

[Ballot comment]
A few comments form Ari Keranen:

1. Introduction

  Nonetheless, the latest IPsec architecture [RFC4301] considered a
  bandwidth limit of 2 bits per packet on a covert channel made it a
  manageable risk.

Remove "made it"?

4. New ECN Tunnelling Rules

  an alternate congestion marking scheme used by a specific Diffserv
  PHB (see S.5 of [RFC3168] and [RFC4774]).

For consistency: s/S/Section/
(also in Section 7 and Appendix B1)

[Ballot comment]
A fine document.  I've only got some non-blocking comments:

#1 - Sometimes RFC4301 and RFC3168 is used when describing the IPsec tunnels and non-IPsec tunnels and sometimes it is used to describe the actual document.  Could IPsec tunnels and non-IPsec tunnels be used instead when discussing the tunnels and [RFC4301] and [RFC3168] be used when describing the document?  I think it would make it clearer.

#2 - If there's one required mode and one optional, then I suggest in Section 4.1:

OLD:

a REQUIRED `normal mode' and a `compatibility mode'

NEW:

a REQUIRED `normal mode' and an OPTIONAL `compatibility mode'

#3 - The tables include codepoints and "drop". Can you add a NOTE that indicates "drop" in the tables is not a codepoint.

#4 - Section 4.2:

This is because the
inner Not-ECT marking is set by transports that use drop as an
                                                       
                                    replace drop with "drop" ?

  indication of congestion and would not understand or respond to
  any other ECN codepoint [RFC4774].

#5 - Section 5.1 & 5.2, please indicate which sections are changed in 4301/3168.  It will aid readers who are familiar with those documents. 

#6 - Section 5.2:

The compatibility mode of encapsulation is identical to the
      encapsulation behaviour of the limited functionality mode of an
      RFC3168 ingress, except it is optional.
                                    ^^^^^^^^r/optional/OPTIONAL?

[Ballot comment]
A quick note.
In the Acknowledegements...

  The views expressed here are those of the
  author only.

I know what you mean with respect to your sponsor, but the views expressed here represent IETF consensus now, so this sentence is not accurate.

[Ballot comment]
> In some circumstances (e.g. pseudowires, PCN), the whole path
> is divided into segments, each with its own congestion
> notification and feedback loop.

The above reference to PWs assumes an agreed  documented MS-PW congestion architecture, whereas the most that exists is a few hints in RFC5659. The reference to PWs should be removed, or the text aligned with RFC5659.

(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?

Gorry Fairhurst, TSVWG Chair

(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?

Yes. This document has been presented in TSVWG, and received comments
and feedback. It has also been presented to the IPsec community. The
WGLC was also copied to PCN, where some of the draft text originated.

(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?

This needs SecDir review, since this updates IPsec. A Secdir review was
requested during WGLC, but none emerged. It is expected that appropriate
security reviews will be sought by the AD.

(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?

There is good consensus to progress ECN work, and support for this
particular work item.

(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?

OK.
Some sections need to be removed prior to publication, as marked.

(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.

(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?

This memo includes no request to IANA.

(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

This document redefines how the explicit congestion notification (ECN)
field of the IP header should be constructed on entry to and exit from
any IP in IP tunnel. It updates RFC3168, aligning this with RFC4301 for
IPsec ECN processing. It also updates RFC4301 to add new behaviours for
previously unused combinations of inner and outer header. This update is
thought to benefit work on PCN and align IP tunnel behaviour with that
of IPSec.

Working Group Summary

The WG contributed to this work and participated in review of this
document. It has the support of the TSVWG.

Document Quality

There are no implementation reports for this specification, but
interoperability issues were discussed in the WG and the current
specification is thought ready for deployment. Most of the final
discussion was on good engineering practice for the future use of the
ECN codepoints. David Black assisted in performing this review and in
review of the normative wording.