Subject: [seamoby] Comments on draft-ietf-seamoby-mm-problem-00.txt

From: James Kempf <[email-masked]>
Date: Wed, 21 Feb 2001 09:12:29 -0800 (PST)

At the risk of being accused of flaming, IMHO this draft is very disappointing.

Much of it reads like a marketing presentation for wireless rather
than a technical analysis of an existing problem and a statement of
how Seamoby should go about solving it. In particular, Section 2.1
reads like a laundry list of Good Attributes For A Wireless IP Mobility
Management Protocol, and Section 4.0 looks like it was lifted from
the Powerpoint slides of a 3G marketing person. There seems to be
an implicit assumption that not changing the IP address is somehow
"good", and that there is really no need to justify why.

The heart of the draft seems to be Section 3.1, in which a comparison
with mobile IP is attempted. But the comparision is merely a list
of desirable features and a few words on whether and how mobile
IP is attempting to solve them. The interesting thing is that on
each issue, the draft seems to imply that work is underway in the mobile
IP group, AAA group, or the Seamoby group (re. paging and context transfer) to
address the shortcomings, yet despite this, the draft concludes
that work is needed on a micromobility protocol!

What I would have liked to see is a technical analysis of the shortcomings
of mobile IP's tunneled approach and how a routing update based approach
would do better. From this analysis, I would expect to see recommendations
about whether or not there needs to be work on a routing update based
micromobility management protocol. Naturally, the recommendation should take
into account the existing mobile IP deployment base (in particular
3GPP2's IOS 4.0) but the recommendation really should be based on specific
technical drawbacks of mobile IP and how a routing update based approach
would solve them. Alternatively, the recommendation could be for a
"next generation" micromobility protocol.

I'm sure the design team members and authors of the draft worked really
hard on this and I respect their technical judgement, but I can't see
sending this statement to the IESG in its current form. There is
really no solid technical justification for the recommendation.

		jak

---

From: Michael Thomas <[email-masked]>
Date: Wed, 21 Feb 2001 11:23:56 -0800 (PST)

James,

It's hard to parse out what is driven by your
general skepticism of mobility without changing
care of addresses vs any shortcomings of the
problem statement. Taking your request for
concrete advantages at face value, I suggest that
you scan over my RSVP analysis draft where it's
pretty clear that MM+CT results in a lot less
signaling. This may be a quirk of RSVP, but 
then again it may not be.

Given that the problem statements are not
suppposed to be tomes, I'm not quite sure what
you'd have them do differently -- they could
include parts of my stuff or other things like it
which is what it seems like you're asking they do,
but that would really bloat problem statement.

	      Mike

---

From: Luca Salgarelli <[email-masked]>
Date: Wed, 21 Feb 2001 15:09:04 -0500

James,

I think this is a chicken-egg problem. I think that what you would have
liked to see ("a technical analysis of the shortcomings of mobile IP's
tunneled approach and how a routing update based approach would do better")
would go into solution space, and we were not allowed to do that in this
draft.

My understanding is that we are still in a phase in which we would like the
blessing of the IESG before *working* on the technical analysis that you
are suggesting, which by the way I would like to see also, and work on as
well.

I hope that this draft will get us that blessing.

Luca