Subject: RE: [mobile-ip] LMM Requirements

From: James Kempf <[email-masked]>
Date: Wed, 2 May 2001 15:09:21 -0700 (PDT)

Hi Raj,

>I do not believe we have WG consensus yet (other than a few views) on
>this issue. Maybe we need to do a consensus call on just this
>requirement and hope that we have a wider response. So if we were to
>do a consensus call on this requirement then the question to the WG
>would be:
>1. Is support for multilevel hierarchies a requirement for LMM?
>2. A single level of hierarchy is sufficient as the requirements for
>LMM can be met by engineering the network right.
>
>Do you agree with the above if we were to do a consensus call...

Actually, no. I much prefer a set of functional requirements as opposed to
a structural one. Something like:

	The protocol shall support the ability to optimize local signalling
	paths without changing the externally visible CoA so as to reduce
	or eliminate frequent end to end BU signalling in cases where network 
	engineering or administrative/deployment considerations require
	small LMM domains.
	
	The protocol shall support optimal placement of LMM agents to
	reduce or elminate additional triangle routing introduced by
	LMM.
	
These leave open exactly how to achieve the required functionality.
Hierarchy is one way, another way that might work is using edge
tunnels as PhilN has suggested. There may even be ways to modify
HMIP to achieve these requirements. 

		jak

---

From: Theo Pagtzis <[email-masked]>
Date: Thu, 03 May 2001 08:52:02 -0700

Raj,

    I would agree with Jak here. The reason:

So far we have relied on a WG consensus (so far partial) to bring some LMM
scheme as a WG item. You or others in the constituency must have witnessed that
such decision was only somewhat "superficial" (with all due respect to anyone
involved) since we have found ourselves working _now_ on a set of post-mortem
requirements for LMMs.

I can thus argue that one could expect that concensus decision on questions
raised are bound to find similar "luck". Simply because not everybody can cope
with the volume of emails that are flooding the MIP/Seamoby/FooMobility
lists...So it is guaranteed that some individuals although they would like to
concede to these questions with some answer, they are bound to see them much
later when they try to "catch up".

For that I would thus, second the sounder approach of having such functional set
of requirements that is there with the additions or deletions that we want to
see in (at least whoever is actively involved in the issue) and then leave it
for individual to peruse and elaborate some more when they have the time..

That is use the list as a carrier of info not as signalling for concensus since
the amount of nodes in inversely proportional to the volume of mail traffic
flooding the aforementioned lists.
(from a protocol perspective... :)

I do not know how the rest feel about it

>         reduce or elminate additional triangle routing introduced by

The placement is closely related to the configuration issue which proves to me
once more the need to be included in even if it has to commence from manual
approaches (that must be extend to a dynamic form so as the LMM scheme can scale
-

Theo

UCL/Mobile Systems