Mobile IPv4 Fast Handovers
draft-ietf-mip4-fmipv4-07

IANA Last Call Comments:

*** Notes:
ICMP registry is inconsistent it says ICMP type 41 is
allocated and below that it is available for assignment.
***

Action #1:

Upon approval of this document, the IANA will make the
following assignments in the "Mobile IPv4 Numbers -
per [RFC3344]" registry located at

http://www.iana.org/assignments/mobileip-numbers

sub-registry "Message Types:"

Type | Description | Reference
TDB1 | Fast Binding Update (FBU) | [RFC-mip4-fmipv4-07]
Section 6.1
TBD2 | Fast Binding Acknowledgment (FBAck) |
[RFC-mip4-fmipv4-07] Section 6.1



Action #2:
Upon approval of this document, the IANA will make
the following assignments in the "Mobile IPv4 Numbers -
per [RFC3344]" registry located at

http://www.iana.org/assignments/mobileip-numbers

sub-registry "Mobile IP Extensions for ICMP Router
Discovery messages:"

+---------+-----------------------------------------+-------------+
| Subtype | Description | Reference |
+---------+-----------------------------------------+-------------+
| TBD3 | Router Solicitation for Proxy Advertisement (RtSolPr) |
[RFC-mip4-fmipv4-07] Section 6.3 |
| TBD4 | Proxy Router Advertisement (PrRtAdv) | [RFC-mip4-fmipv4-07]
Section 6.4 |
| TBD5 | Handover Initiate (HI) | [RFC-mip4-fmipv4-07]
Section 6.5 |
| TBD6 | Handover Acknowledge (HAck) | [RFC-mip4-fmipv4-07]
Section 6.6 |
+---------+------------------------------------------+-------------+


Action #3
Note:
From the document it looks like actions #2 and #3
update the same registry.
I have kept these as two different actions in case
this is a mistake. Editors please affirm or point
out exactly the correct registries intended for
actions.


Upon approval of this document, the IANA will make
the following assignments in the "Mobile IPv4 Numbers -
per [RFC3344]" registry located at

http://www.iana.org/assignments/mobileip-numbers

sub-registry "Mobile IP Extensions for ICMP Router
Discovery messages:"

+-------+------------------+-------------+
| Type | Description | Reference |
+-------+------------------+-------------+
| TBD7 | Link-Layer Address Option Format (LLA) |
[RFC-mip4-fmipv4-07] Section 7.1 |
| TBD8 | New IPv4 Address | [RFC-mip4-fmipv4-07] Section 7.2 |
| TBD9 | New Router Prefix Information | [RFC-mip4-fmipv4-07] Section 7.3 |
+-------+------------------+-------------+


Action #4:
Upon approval of this document, the IANA will make
the following assignments in the "Mobile IPv4 Numbers -
per [RFC3344]" registry located at

http://www.iana.org/assignments/mobileip-numbers

sub-registry "Generalized Authentication Extension:"

Subtype | Description | Reference

TBD10 | MN-PAR Auth Extension | [RFC-mip4-fmipv4-07]
Section 6.1,



We understand the above to be the only IANA Actions
for this document.

[Ballot comment]
Gen-ART Review by Francis Dupont ...

  Some editorial comments:
  at page 6 section 4.2:
  - in FA COA mode -> in FA-COA mode
  - for the FSU field, I propose to add a MUST somewhere,
    for instance: are used -> MUST be used

  For each field: XXX field must be -> XXX field is

  Throughout: Acknowledgement -> Acknowledgment

  In Security Considerations, page 8, there is nothing about replay
  attacks, i.e., how the "come back to where you was" attack is
  handled?  In IPv6 the protection is provided by IPsec with in the
  good case anti-replay, is it done in IPv4?

[Ballot comment]
ABSTRACT:
>    Additional mechanisms may be defined in the
>    future versions of this document.

  Suggest to remove this sentence - this is being published now.

AD review posted to the list:

I have reviewed this specification and while it is generally
in good shape for an Experimental RFC publication, there
were a number of questions and issues that I believe need
to be addressed before we can go to IETF Last Call.

In Section 3, did you mean "default router reachability"
when you wrote "default agent reachability"?

Section 6.3 says this:

> > New Access Point Link-layer Address: The link-layer address or
> > identification of the access point for which the MN requests
> > routing advertisement information. It MUST be included in all
> > RtSolPr messages. More than one such address or identifier can
> > be present. This field can also be a wildcard address (see
> > Section 7.1).

And then later Section 6.4

> > New Access Point Link-layer Address: The link-layer address or
> > identification of the access point is copied from RtSolPr
> > message. This option MUST be present.
> >
> > ...
> >
> > New CoA Option: MAY be present when PrRtAdv is sent
> > unsolicited.

There are a couple of issues around the role of New Access Point
Link-layer Address option. Since you allow wildcards, what does
the copying requirement mean? Copy the wildcard, or the matching
entries?

> > New CoA Option: MAY be present when PrRtAdv is sent
> > unsolicited. PAR MAY compute new CoA using NAR's prefix
> > information and the MN's L2 address, or by any other means. In
> > any case, the MN should be prepared to use this address instead
> > of performing DHCP or similar operations to obtain an IPv4
> > address.
First, why would this be present only in an unsolicited message?

Second, the combination of prefix and L2 address appears to be
copied from IPv6 and not directly applicable in IPv4.

Third, how is the lifetime of this address determined? When can the
new access router re-allocate the same address for someone else?
Why is there no instruction on what the NAR/PAR does in order to
find such addresses. RFC 4068 had these instructions... Or are you
saying in Section 1 that you always use foreign agent care-of
address? If so, please require this later in the document when
you transport the addresses around.

In Section 6.4 you say:

> > New Access Point Link-layer Address: The link-layer address or
> > identification of the access point is copied from RtSolPr
> > message. This option MUST be present.
> >
> > ...
> >
> > A Proxy Router Advertisement with Code 3 means that new router
> > information is only present for a subset of access points requested.
> > The Option-Code values in the LLA option distinguish different
> > outcomes (see Section 7.1).

If we get Code 3, is there a New Access Point Link-layer Address
option included anyway? What would its contents be, in this case?

> > Type: To be assigned by IANA
> >
> > Code: 0
RtSolPr and PrRtAdv ask for an ICMP Type code
to be assigned. I'm trying to understand why,
given that RFC 4068 uses type code 150 allocated
in RFC 4065 for experimental mobility purposes.
RFC 4065 has a corresponding type code for IPv4,
too (value 41).

> > 9. IANA Considerations
> >
> > All the messages and the option formats specified in this document
> > require Type assignment from IANA. Specifically, the Types, Sub-
> > types and the Codes need assignment from ICMP, Mobile IP and
> > Experimental Mobility Type [rfc4065] registries.

It took a while for me to parse what this means, and it would be
better if you can write the IANA instructions in a more explicit
manner. In particular, you are asking ICMP Types and Mobile IP
Type allocations, so at least explain what values are allocating
from what registry. Also, this section may be affected by
any changes resulting from my previous comment.

Finally, the IANA considerations section is missing all instructions
regarding future allocations from Option-Code and Code fields.
Are these namespaces expected to be independent new spaces,
or go in sync with RFC 4068?

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?

Pete McCann is the document shepherd. Yes, I have personally
reviewed the document and 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?

The document went through last call back in September of 2005 and
has been discussed actively. We feel the document has obtained
sufficient review, and I have no concerns about the depth or breadth
of the reviews.

> (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.

No concerns. All issues have been addressed.

> (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 solid WG consensus behind the document.

> (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 appeals have been threatened.

> (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?

The document has been checked for nits. No nits found by the automated
checker and no nits found by proofreading. The draft does not have any
serious dependencies on other working groups so the review done by MIP4
probably suffices.

> (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, references are split. All normative references are published RFCs.
As this draft is intended for Experimental status, there are no downward
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 suggested a
> reasonable name for the new registry? See
> [I-D.narten-iana-considerations-rfc2434bis]. 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 document contains a detailed IANA section. The document does not
create any new registries. The requested allocations are described with
appropriate references to the number spaces.

> (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?

There are no formal language descriptions in the document.

> (1.k) The IESG approval announcement includes a Document
> Announcement Write-Up. Please provide such a Document
> Announcement Writeup? Recent examples can be found in the
> "Action" announcements for approved documents. The approval
> announcement contains the following sections:
>
> Technical Summary

The document describes a new protocol designed to reduce the
latency and packet loss experienced during handover. It does
so by introducing new messages to be used among the Mobile Node (MN),
Previous Access Router (PAR) and New Access Router (NAR). The
messages allow the MN to establish a binding at the PAR such that
packets are forwarded to/from the NAR immediately after a handover.
This avoids the long round-trip time to the home network that would
be incurred by a standard Mobile IPv4 messsage flow.

> Working Group Summary

The document underwent working group last call in September 2005,
and has been actively discussed and edited since then.

> Personnel
> Who is the Document Shepherd for this document? Who is
the
> Responsible Area Director?

Pete McCann is the document shepherd. Jari Arkko is the responsible AD.

-Pete