Subject: Re: [MOBILE-IP] [Fwd: draft-ietf-mobileip-3gwireless-ext-04.txt]

From: "Lipford, Mark" <[email-masked]>
Date: Fri, 18 Aug 2000 15:30:33 -0500

If has actually been published in IS-2001 and is being developed to (I
hope).

Mark A. Lipford

                -----Original Message-----
                From:   Charles E. Perkins [mailto:[email-masked]]
                Sent:   Friday, August 18, 2000 3:27 PM
                To:     [email-masked]
                Subject:        [MOBILE-IP] [Fwd:
draft-ietf-mobileip-3gwireless-ext-04.txt]

                Hello folks,

                I have sent the following message earlier this afternoon, in
an
                attempt to reopen discussion about the abovementioned
Internet
                Draft which is currently under consideration for
Experimental status.

                Yingchun has informed me that the 3gwireless approach has
been
                implemented as part of the IOS 4.1 standard within CDMA2000.
                I do not know whether that should affect the discussion at
this
                point in time.

                Regards,
                Charlie P.

                -------- Original Message --------
                Subject: draft-ietf-mobileip-3gwireless-ext-04.txt
                Date: Fri, 18 Aug 2000 13:08:28 -0700
                From: "Charles E. Perkins" <[email-masked]>
                Organization: Nokia Research Center
                To: [email-masked],
[email-masked],[email-masked],
                [email-masked],[email-masked],Gopal
Dommety
                <[email-masked]>,
[email-masked],[email-masked],

[email-masked],[email-masked],
                [email-masked],[email-masked], [email-masked],
                [email-masked],[email-masked], [email-masked],
                [email-masked],[email-masked],
                [email-masked],[email-masked],
                [email-masked],[email-masked],
                [email-masked],[email-masked],
                [email-masked],"Lipford, Mark"
                <[email-masked]>,[email-masked],
[email-masked]
                CC: Tom Hiller <[email-masked]>,Phil Roberts
                <[email-masked]>,"Basavaraj Patil (NTC/Dallas)"
                <[email-masked]>,David Oran <[email-masked]>, Rob
Coltun
                <[email-masked]>
                BCC: Pat Calhoun <[email-masked]>,James Kempf
<[email-masked]>

                Hello draft co-authors,

                >From the discussion below, and after a careful re-reading
of the draft,
                I hope to show that this protocol specification does not at
all fit
                well within the mainstream of work within the mobile-ip
working group.
                I believe that it is actively harmful, because any core
network
                implementing their protocol would find it correspondingly
much more
                difficult to implement "actual" Mobile IP specifications.  I
say
                "actual" in quotes because the specifications in question
are not
                yet Proposed Standard, and also because I do not think that
the
                3gwireless specification fits well in its current
formulation nor
                has it received sufficient working-group review.

                The first basic problem with the 3G wireless draft is the
specification
                of the Registration Update and the Registration
Acknowledgement
                message types.  Neither of them is clearly specified, and to
the
                extent that I understand their purpose, neither one is
necessary.
                The intended results of those messages are done better by
use of
                the Binding Update and Binding Acknowledgement messages
which are
                already specified in the Route Optimization draft.

                The respecification of the Registration Request draft is
also
                faulty, and exhibits the well-known fallacy of doing the
same
                thing in two different ways.  In this particular instance,
we
                see that the alt-Registration Request message has failed to
keep
                up with recent developments regarding the 'V' bit.  We can
expect
                this to continue, especially given the strong likelihood
that
                some new Mobile IP developments will involve interactions
between
                the Registration Request message and AAA services.

                Figuring out when to send an alt-Registration Request will
be
                additionally complicated by the standardization of the
upcoming
                Regional Registration protocol specification, which is
currently
                in Last Call.

                Another element of confusion is represented by the lack of
                IP addressability for mobile nodes subordinate to the
protocol
                operations described in the 3gwireless draft.  In fact,
nowhere
                in the draft is there any indication that mobile nodes in
their
                system will have IP addresses.  Furthermore, mobile nodes in
                this draft are basically identified by a MN ID field, which
is
                expected to be the same as the mobile node's IMSI.  Recent
work
                within the mobile-ip working group has gone in the direction
of
                using the NAI for analogous purposes of allowing a
Registration
                Request to emanate from a mobile node that does not yet have
                a home address assigned.  I would suggest that the
3gwireless
                draft use the NAI extension instead of their current MN ID.
                The IMSI is widely expected to show up as data within NAI
                extensions to Mobile IP registration requests, so this
should
                not cause any problems to the 3gwireless authors.

                As an example to support my contention that this draft is
actively
                harmful to current work items within the mobile-ip working
group,
                say that a PDSN implements Regional Registrations.  This is
very
                likely, given recent discussion.  How then would such a PDSN
manage
                its route tables if it ever received a message on port 697?
                It might be very difficult to figure this out.  It would be
                possible to get messages that required incompatible
operations.

                Similarly, if a mobile node implements smooth handover
messages
                using IPv4 Binding Updates, then there would be a conflict
between
                actions required by the Binding Update message and the port
697
                messages.

                I have numerous other syntactic and editorial comments that
I
                think would need attention before the draft should be
considered
                at all.  If need be, I will supply these additional
comments.
                However, before going to that trouble, I think that it is
more
                important to consider the viability of the draft.  I hope
that the
                authors of the draft will follow through on their previous
agreement
                to find a better integration strategy with other existing
mobile-ip
                working group drafts, specifically including Route
Optimization and
                Regional Registration.  If it is the contention of the
3gwireless
                authors that the previous drafts are too complicated for
their
                implementation purposes, then we should have the discussion.
                I have offered to do so, more than once.  One possible
outcome
                would be to get simpler drafts for specific protocol
features
                needed by the 3gwireless authors.

                I note that Nortel Networks had brought some similar
concerns to
                light a couple of years ago, and we reached a beneficial
improvement
                to the Route Optimization draft which allowed the inclusion
of
                multiple correspondent node addresses in the Binding Warning
                message.  I fully expect that we can make similar
improvements
                as needed to the IPv4 Binding Update message for use in the
                role needed by the authors of the 3gwireless draft.

                I also note that the name of the draft is misleading.  As
far as
                I know, there is no consensus behind this protocol
specification
                within 3GPP or within MWIF.  I also do not think there is
any
                consensus behind this protocol within 3GPP2, but I note that
                several of the listed authors are indeed active within
3GPP2.
                My guess is that this draft has limited support even there.
But
                either way, it seems very clear to me that the draft should
NOT
                be named in any way to imply that it represents _the_ 3G
solution
                for wireless mobility management.  Far from it.

                Lastly, I note that this draft has attracted almost no
discussion
                within the mobile-ip working group.  When I asked several
others
                about it, they said it was because most people generally
don't care.
                But I care.  I care because I think it is damaging to the
progress of
                other longstanding mobile-ip working group items.  In order
to best
                meet the needs of all parties, I offer my best effort to
work with
                the authors of the 3gwireless draft to make the other drafts
meet
                their needs.  I hope this will be sufficient to resolve what
could
                otherwise be a situation causing problems for the future.

                Sincerely,
                Charles E. Perkins

                PS. I regret that I have only now been able to make time for
this
                    set of comments.  It would have been much better to
raise the
                    discussion during working-group last call, but that
slipped
                    right by me and was over before I knew it.

---

From: "[email-masked]" <[email-masked]>
Date: Fri, 18 Aug 2000 13:41:15 -0700

> If has actually been published in IS-2001 and is being developed to (I

How could it have been published, without an RFC number, given that the
document would surely be a normative reference?

PatC