Generic Routing Encapsulation (GRE) Key Extension for Mobile IPv4
draft-ietf-mip4-gre-key-extension-05

[Ballot comment]
Something is wrong here:
  >
  > 4.2.  Home Agent Requirements for GRE Tunneling Support
  >    [RFC3344]
  >
  The reference is misplaced.  I think it belongs in the first
  sentence of the section.

  Please remove the extra spaces:
  >
  >    GRE encapsulation, it MUST send an RRP with code 'Requested
  >    Encapsulati on Unavailable (139)' [RFC3024] .

[Ballot comment]
I have no objection to the publication of this documen, but there are a few small points that might be addressed to improve it.

---

I don't think you need RFC 2119 notation in the Abstract.

---

A number of acronyms are used without expansion

---

Sections 4.1, 4.2, and 4.3 seem a bit confused on the use of RFC 2119
language and the cases where behavior is already defined in other
specifications. Could you spend a little time to clear this up and make
clear what new behavior this document is defining.

[Ballot comment]
1) Nits points out:

-  ** Obsolete normative reference: RFC 3344 (Obsoleted by RFC 5944)

2) If you end up doing another revision, please:

a) expand GRE on 1st use in Abstract and Introduction.

b) add a period to the end of the 1st paragraph in Section 7.

Otherwise, please consider these during AUTH48 (if the RFC editor doesn't catch them).

[Ballot comment]
1) Nits points out:

-  ** Obsolete normative reference: RFC 3344 (Obsoleted by RFC 5944)

2) If you end up doing another revision, please:

a) expand GRE on 1st use in Abstract and Introduction.

b) add a period to the end of the 1st paragraph in Section 7.

Otherwise, please consider these during AUTH48 (if the RFC editor doesn't catch it).

[Ballot comment]
"In the absence of this key identifier, the data streams cannot be distinguished from each other, a significant
drawback when using IP-in-IP tunneling."

Well understated.

FA, HA, RRP, MN, RRQ, RRP used without first expansion.

It would be useful to the reader if the 'G' bit was called by it's proper name (GRE Encapsulation) on first used, same for the 'D' bit.

'The FA may include a GRE key of value zero in the GRE Key Extension to signal that the HA assign GRE keys in both directions.' - Minor grammar problem.

'Encapsulati on Unavailable' - - Minor grammar problem.

IANA has a question about the IANA Actions related to this document.

IANA understands that, upon approval of this document, a single IANA
Action is required.

The GRE Key Extension is understood to be a Mobile IP extension and a
Type value for this Extension should be registered from the
non-skippable range (0-127).

IANA Question --> which of the MobileIPv6 Extension registries should
this type value be added to?

IANA understands that this is the only action required to be completed
upon approval of this document.

State changed to In Last Call from Last Call Requested.

The following Last Call Announcement was sent out:

From: The IESG
To: IETF-Announce
CC:
Reply-To: ietf@ietf.org
Subject: Last Call:  (GRE Key Extension for Mobile IPv4) to Proposed Standard


The IESG has received a request from the Mobility for IPv4 WG (mip4) to
consider the following document:
- 'GRE Key Extension for Mobile IPv4'
  as a Proposed Standard

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 2011-03-14. 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-mip4-gre-key-extension/

IESG discussion can be tracked via
http://datatracker.ietf.org/doc/draft-ietf-mip4-gre-key-extension/

State changed to AD Evaluation from Publication Requested.
I have reviewed this draft. The document is basically in good shape, was easy to read, and I have sent it forward to IETF Last Call and an eventual IESG review (currently scheduled for March 17th). I did have two comments, however, and I hope that the authors can address them even if the last call period is starting:

> The HA SHOULD accept the RRQ and send a RRP with code 'Accepted (0)'.
> The HA MUST assign a GRE key and include the GRE Key Extension in the
> RRP before sending it to the FA.  The HA MUST include the GRE Key
> Extension in all RRPs in response to any RRQ that included GRE Key
> Extension, when a GRE key is available for the registration.

The acronyms RRQ and RRP not defined before in this document.

Also, the above does not leave room for other issues and error conditions. What if the HA wants to deny the request for some other reason, not related to GRE at all?

> The HA MUST follow the procedures specified in RFC 3344 in processing
> this extension in Registration Request messages.  If the HA receives
> the GRE Key Extension in a Registration Request and does not
> recognize this non-skippable extension, it MUST silently discard the
> message.

Perhaps this is already explained in some other document, but how does one recover from this situation.

Jari

(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 Pete McCann. Yes, I have reviewed
this version of the document and I believe it 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?

Yes, and no.

(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.

No concerns. No IPR disclosure related to this document has been filed.

(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?

Consensus is solid.

(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?

One nit: the reference to RFC3344 should be replaced with RFC5944.

(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].

The document contains only normative references, contained in a
properly labeled "Normative References" section. No downward
refs are present.

(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 section requests allocation of one Mobile IP Extension Type
needed by the document. Missing is a request to allocate the Subtype
registry for this type.

(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 formal languages 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
The GRE specification contains a Key field, which MAY contain a value
that is used to identify a particular GRE data stream. This
specification defines a new Mobile IP extension that is used to
exchange the value to be used in the GRE Key field when GRE
tunneling is used.

Working Group Summary
Considerable time was spent discussing whether the presence
of a GRE key extension inserted by an FA can override the setting
of the 'G' bit by the MN. We decided that it can, but only when
using FA-located tunneling.

Document Quality
The protocol has been implemented in vendor-specific 3GPP2
extensions previously. The idea is well understood and the present
document is of high quality.