Mobile IPv6 Fast Handovers for 3G CDMA Networks
draft-ietf-mipshop-3gfh-07

[Ballot discuss]
(Updated discuss text)

The spec defines a new MN ID type for IMSI, but is vague about the
exact contents of the field (i.e., how exactly the IMSI is encoded
when placed in this field). Ditto for AN ID and Sector ID. For all
of these, a (normative) reference to some 3GPP/3GPP2 spec (preferably
with a specific section number where the information can be found)
should be enough.

The document requests the allocation of a new Mobile Node Identifier
Option Subtype. According to RFC 4283, this space has "Standards
Action" allocation policy -- but this document is going for
Informational?

[Ballot discuss]
The spec defines a new MN ID type for IMSI, but is vague about the exact
contents of the field (and doesn't give a normative reference either).
Ditto for AN ID and Sector ID.

[Ballot discuss]
The spec defines a new MN ID type for IMSI, but is vague about the exact
contents of the field (and doesn't give a normative reference either).

[Ballot discuss]
Discuss-discuss: Sections 6.3 and 6.4 allocate and use bits that the
  MIP6 standards track RFCs declared as reserved and did not specify an
  allocation procedure for. In my opinion, this requires that this
  document update those RFCs, and I'd like to discuss if it can, given
  that it is Informational and those documents are standards track. (I
  don't understand why this document is Informational, anyway. It reads
  like a specification.)

[Ballot comment]
The second use of MAY (as a MAY not) in 5.2 (b) is inconsistent with my reading of
RFC 2119 and besides, it seems ambiguous to me:

  (b)  The proxy router advertisement MAY be sent to the MN, but the
        prefix of the NAR MAY not be included.

Is it optional, as in don't count on the prefix being included, or is it not permitted?

I suggest rewriting the second clause to describe when the prefix of
the NAR is (or is not) included.

[Ballot discuss]
The "TBD" in Section 6.2 is listed in the IANA considerations, but
  the "T.B.D." in Section 6.1 is not in the IANA considerations.

IANA Last Call comments:

Please confirm that the following actions are correct:

Action #1:
Upon approval of this document, the IANA will make the following
assignments in the "ICMPv6 TYPE NUMBERS" registry located at
http://www.iana.org/assignments/icmpv6-parameters
Registry: "IPv6 Neighbor Discovery Option Formats"

Type  Description                        Reference
-----  ----------------------------        ---------
TBD1  Handover Assist Information Option  [RFC-ietf-mipshop-3gfh-05.txt]
TBD2  Mobile Node ID Option              [RFC-ietf-mipshop-3gfh-05.txt]


Action #2:

Upon approval of this document, the IANA will create the following
sub-registry in the "ICMPv6 TYPE NUMBERS" registry located at
http://www.iana.org/assignments/icmpv6-parameters

Sub-registry name: Handover Assist Information Option codes
Reference: [RFC-ietf-mipshop-3gfh-05.txt]
Registration Procedures: IETF Review or IESG Consensus

Value  Description              Reference
-----  ------------------------  ---------
1      ANID                      [RFC-ietf-mipshop-3gfh-05.txt]                             
2      Sector ID                [RFC-ietf-mipshop-3gfh-05.txt]

QUESTION: Is there an upper limit on values that can be assigned
(e.g., 255)? Should "0" be marked reserved?


Action #3:

Upon approval of this document, the IANA will create the following
sub-registry in the "ICMPv6 TYPE NUMBERS" registry located at
http://www.iana.org/assignments/icmpv6-parameters

Sub-registry name: MN ID Option codes
Reference: [RFC-ietf-mipshop-3gfh-05.txt]
Registration Procedures: IETF Review or IESG Consensus

Value  Description                                            Reference
-----  -----------------------------------------------------  ---------
1      IMSI ("Mobile Node Identifier Option Subtype" [RFC4283])  [RFC-ietf-mipshop-3gfh-05.txt]                             


QUESTION: Is there an upper limit on values that can be assigned
(e.g., 255)? Should "0" be marked reserved?

QUESTION: Does section 6.3 require any registrations? If so,
which registry is it referring to?

I have done my AD review on this document as well. It still
needs work. Here are my comments:

1. References should be updated to point to RFC 4068bis.

2. The spec needs to be clearer about when FMIP procedures are
  needed upon link change, and when not. Is a link change in 3G
  CDMA networks always a subnet change, too? Text several places
  in the document appears to assume this is so.

3. The spec needs to document how it deals with the issues
  from RFC 4907 Section 2.

4. A review from 3GPP2 or experts in 3GPP2 networks is required.

5. I do not understand how it is possible to use the interface
  ID (you mean the IP layer interface ID, right?) in the
  MN-LLA option, as suggested in Section 5.1.

6. I do not understand the instructions in Section 5.1
  regarding UNA. It appears that this draft is disobeying
  a MUST from RFC 4068bis. If UNA is not applicable in all
  cases, is there something that needs to be fixed RFC 4068bis?

7. I do not understand what "SHOULD be confirmed that NAR
  supports this [IPCP] option" means. Confirm how? The delay
  that you try to avoid is part of normal PPP processing, so
  are you expecting something to be done configuration-wise?

8. In the end of Section 5.1, the advantage of being able to
  avoid PPP authentication, RA, etc is brought up. Some of
  these optimizations are potentially very useful, but I would
  argue that it is not the place of FMIP-over-Foo to define
  everything that can be optimized in Foo. It should only
  define how to run FMIP over Foo.

9. The spec needs to talk about the case where L2 indications
  that Section 5.2 relies on are unreliable or turn out to be
  wrong. E.g., the connection was closed but came back to the
  same router again.

10. It is unclear how Steps a-b differ from each other in Sections
    5.1 and 5.2. Step b in the latter says that prefix information
    is not sent. How do the devices know whether reactive or predictive
    mode is being employed? Section 5.1 Step a talks about data that
    the MN needs to attach to the proxy solicitation. Is such data
    required, allowed, or disallowed in Section 5.2 step a?

11. Flows in both Section 5.1 and 5.2 appear to missing the
    security details outlined in mipshop-handover-key.

12. Section 5.3, network controlled handover. This is a possible use
    of the router-to-router messages of FMIP. But would such use follow
    all the requirements in the FMIP spec? I'm not sure the spec has
    all the details, how would the routers know about the interface IDs
    in use by the mobile node, for instance. Also, my read of the charter
    does not include development of network-based version of FMIP.

13. Section 6.1, handover assist information option. I have
    interoperability concerns about this, and in general we should
    not define completely open options. Please replace by a more
    specific option that can carry the information needed for 3GPP2
    network identification, not a container that can carry anything
    by anyone.

14. Section 6.2, the B option. If such instruction for buffering
    is needed, why isn't it a part of the base protocol?

15. Section 7, s/trusting/trust/. Is draft-ietf-mipshop-handover-key
    required or not?

I am expecting a revised draft and answers to the questions above.

PROTO Write-up

(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?

Vijay Devarapalli is the Document Shepherd for this document. I
have reviewed the document and 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?

This document has been adequately reviewed. 3GPP2 review might
have been a good thing to have, but never got any response from
3GPP2.

(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.

(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 WG consensus in advancing this document.

(1.f) Has anyone threatened an appeal or otherwise indicated extreme
discontent? If so, please summarize 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
http://www.ietf.org/ID-Checklist.html 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? If the document
does not already indicate its intended status at the top of
the first page, please indicate the intended status here.

Idnits found a couple of minor issues. 2461 is referred instead of
4861. The document uses "MUST not" instead of "MUST NOT" in one
instance. This will be fixed in the next revision.

(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 splits the references into normative and Informative
references. There are no downward references.

(1.i) Has the Document Shepherd verified that the document's IANA
Considerations 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 [RFC2434]. If the
document describes an Expert Review process, has the Document
Shepherd conferred with the Responsible Area Director so that
the IESG can appoint the needed Expert during IESG Evaluation?

The IANA considerations section exists and is consistent with
the body of the document. The document requests reservations in
the appropriate IANA registries. The IANA registries that need to
be modified/created are clearly identified.

(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?

Does not apply.

(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.

Mobile IPv6 is designed to maintain its connectivity while moving
from one network to another. It is adopted in 3G CDMA networks as a
way to maintain connectivity when the mobile node moves between
access routers. However, this handover procedure requires not only
movement detection by the MN, but also the acquisition of a new
care-of address and Mobile IPv6 registration with the new care-of
address before the traffic can be sent or received in the target
network. During this period, packets destined for the mobile node
may be lost, which may not be acceptable for real-time application
such as Voice over IP (VoIP) or video telephony. This document
specifies fast handover methods in the 3G CDMA networks in order to
reduce latency and packet loss during handover.

Working Group Summary
Was there anything in the WG process that is worth noting?
For example, was there controversy about particular points
or were there decisions where the consensus was
particularly rough?

No.

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?

Nothing is known about existing implementations or plans for
implementation.

Personnel
Who is the Document Shepherd for this document? Who is the
Responsible Area Director? If the document requires IANA
experts(s), insert 'The IANA Expert(s) for the registries
in this document are .'

Document shepherd: Vijay Devarapalli
Responsible AD: Jari Arkko/Mark Townsley