Subject: RE: [mobile-ip] Protocol Decision Fixed?

From: "Karim El-Malki (ERA)" <[email-masked]>
Date: Fri, 27 Apr 2001 13:24:52 +0200

Hello Jim

> I don't agree with Karim that one LMM per cloud is all that 
> will ever be
> needed simply because the cloud will be too large in some 
> cases as a metro
> network (e.g. LA, Boston, London, Tokyo, Paris).

My point was the other way round. I don't think that LMM
clouds/domains will be so small so that you continuously have
to change LMMs when you move. I agree that you wouldn't want
to have a LMM cover LA, Boston etc. On the other hand a LMM
could cover LA or a parts of LA, which makes changing the LMM a
rare event. I think it's been said previously that you can design
the network appropriately for this.

> Also think about this.  I leave my office and I am mobile with my PDA
> gambling on the horses and keep doing it in my car.  While 
> heading to the
> bar I hit another access router and then in the bar I hit 
> their wireline
> 10MB xDSL access router and get a cheaper rate and jump off 
> the metro cost
> to the xDSL cheaper cost.  Still gambling in the bar on my 
> PDA.  Then I
> jump into a taxi to get home and hit the metro again.  Then I 
> finally get
> home watching the wagers on the last race in my house and now 
> jump on that
> Access Router at my home xDSL which is the cheapest rate for 
> connectivity
> via my access point in my house.  Win a million dollars and go to bed.
> 
> I would argue the above was all in the same cloud in metro LA and the
> wager access was in the city seciton I work, party, and live 
> in.  Its a
> subset of the cloud.  And there were other subsets in the 
> cloud (the car,
> taxi, bar, home) which are LMMs.  

OK. But such a multi-access ISP (xDSL, wireless) could also achieve this
by having one LMM (or a set of them for reliability and sharing of MN
load) and ARs connected to the different access technologies through
the city (i.e. what you called subsets in the cloud). You could still move,
get the different rates and change technologies, but you wouldn't have
to change LMM. Do you need to have/use a LMM in the bar and at home?

Regards
/Karim

---

From: "Phil Neumiller" <[email-masked]>
Date: Fri, 27 Apr 2001 06:30:02 -0500

Some comments.
----- Original Message -----
From: "Karim El-Malki (ERA)" <[email-masked]>
To: <[email-masked]>
Sent: Friday, April 27, 2001 6:24 AM
Subject: RE: [mobile-ip] Protocol Decision Fixed?

> to change LMMs when you move.

Well, you will be changing access routers almost every time
and definitely when you cross AD boundaries right?

-Phil

---

From: Jim Bound <[email-masked]>
Date: Sat, 28 Apr 2001 00:12:39 -0400 (EDT)

Hi Karim,

> the network appropriately for this.

How dispersed the LMMs are should be up to the providers and is really a
business decision in the market not a protocol decision.  At least I
believe the protocol or design should not force a specific business
decision.  I believe this can be architected and then engineered to
support multiple models and maintain interoperability.  Which should have
a strong weight as to which protocol is used to support the model we
define from this discussion thread for requirements.

I hate to state such a strong position at this point in the discussion but
when I agreed that the HA should be left untouched I was also saying that
having to send a HA an updated CoA is also not optimal and though
bicasting is used in the celluar world I do not believe it is required or
needed for MIPv6 model, architecture, or engineered solution (all three
are needed and I think we are still discussing the 'model' IMO).  In fact
to jump way down to a detail I believe the LMMs at the lowest level of
hierarchy can use IPv6 site-local addresses for LMM Area communications
and for signaling too.  Only when talking to the CN is a new
LMM-Specific-CoA required.

So taking my example the paging for the PDA in the bar for that LMM can
use site-local addressing with IPv6.  But the TCP/UDP/SCTP packet to enter
my chit to the wager CN would use the LMM global-LMM-CoA.

At this point I will also point to James's LMM Analysis and PDF file he
sent where I can't refute the math and took the time to check it once. So
the idea is that hierarchy will work and is more scalable I believe that
work proves.
 
> to change LMM. Do you need to have/use a LMM in the bar and at home?

Of course this is possible and my LMM at the bar/taxi was extrapolation.
But I think the case I am presenting is stating there are multiple LMMs
and they may not always be linear (flat or all a the top) but distributed
as we are discussing, much like a binary tree.

As Butler Lampson often stated a long time ago.  Every problem in computer
science can be solved by another level of indirection.  I have been unable
to see that precept not valid as an architect or engineer writing code.

Why we would not use this principle for MIPv6 is beyond me still.
Maybe my day job has me distracted :-------)

regards,
/jim