Subject: RE: Multiple Levels of LMM agents (was: RE: [mobile-ip] Revised L ocalized Mobility Management Requirement s)

From: James Kempf <[email-masked]>
Date: Fri, 20 Apr 2001 12:42:52 -0700 (PDT)

Raj,

>I do not think we should rule out multiple levels of LMM agents from
>the requirements at this stage, but let's discuss the implications of
>a multi-level hierarchy from a routing, deployment, failure-point etc.
>perspective. Obviously there are quite a few people who feel quite
>strongly about it and to rule it out would be unwise. 
>

Ulimately, the issue is one of deployment. The worst possible case
is we cycle an LMM protocol without multiple levels of hierarchy
to proposed and discover during deployment that we need it. 

		jak

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From: Erik Nordmark <[email-masked]>
Date: Tue, 24 Apr 2001 07:56:32 -0700 (PDT)

> to proposed and discover during deployment that we need it. 

Jim,

You are stating the design philosophy that leads to kitchen sink
protocols - put in as much as possible to make sure nothing we can
ever imagine has been left out.

I much prefer the opposite philosophy - only include what we know for 
sure will be needed.

   Erik

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From: Theo Pagtzis <[email-masked]>
Date: Tue, 24 Apr 2001 10:34:13 -0700

Hi Erik,

   I am not sure if you have seen the reasons I have provided for
multi-level hierarchy in previous postings.

While I have not seen any arguments against  them you claim that we are
trying to include everything in the requirements including the kitchen
sink...I feel that this is not the case.

I did not present previous reasoning as a nicety but as an upcoming (in
the very near future) need. I feel that short-sighted requirements
specifications is bound to meet serious revisiting later and as such
lack of concrete consideration.

I am sure that you would agree that when you design for a protocol you
do not only cater for what you need right now. In my book this is called
patchwork since the so called incremental evolution in protocol can only
bring side-effects to the core features..twist that tweak there and the
protocol as a totality looks like Frankenstein...

So I would argue against the philosophy of "include what we know for
sure will succeed". This looks to me like a telecoms attitude.. that
would take on only what is a guaranteed success...perhaps people these
days are influenced more by the Nasdaq indexes..

But in anycase there is no such case that we know for sure it will
succeed with the current set of requirements for LMM..nobody has
deployed such scheme yet (to my knowledge)..we are only trying to be
robust and complete on important issues that the constituency feels
strongly about LMM. I believe that this is far from "kitchen sink"
reflections...

Theo

UCL/ Mobile Systems