Subject: [mobile-ip] About draft-jung-mobileip-fastho-hmipv6-00

From: "Sha Liu" <[email-masked]>
Date: Sun, 18 May 2003 11:29:21 +0800

Hi,
    Does anyone agree that the MAP will be overburdened?

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From: Greg Daley <[email-masked]>
Date: Mon, 19 May 2003 10:16:38 +1000

>     Does anyone agree that the MAP will be overburdened?

It depends on the map allocation policy, and the MNs'
choice of MAPs.

It may be that the MAPs are either built into large
robust servers like in 2/3G SGSN/GGSN routers (this may be
simply a software upgrade for existing devices).

Alternatively, preference settings on different
sets of subnets could be used to advertise MAPs differentially
to nodes entering a region.

For example with a region of 27 networks, we could have sets of 9
networks, each of which advertise one of 3 MAPs as primary.
MNs roaming within a domain may keep the same MAP as orignally bound 
when entering the domain.

This would have some load balancing effect.

Once again, it depends on how many networks/subscribers there are
covered by the MAP.

closer==>less subscribers, more MAP handovers, less location privacy,
              less handover latency

further==> more subscribers, less MAP handovers, more location privacy,
              more? handover latency

Even if there's a possible scalability issue, there may be management
advantages in the administration of the security associations.
Simplistically, there will be fewer security associations across a
set of cells.
ARs->MAPs: O(N*M), compared to ARs-ARs: O(N*N-1).

Greg

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From: "Seok Joo Koh" <[email-masked]>
Date: Mon, 19 May 2003 15:48:24 +0900

Greg, thanks for your valuable and practical comments.

As Greg's comments, I believe, the scalability or overburden issue of HMIP
could be resolved by some elaborated engineering techniques,
as we can see the examples of the 2/3G commercial deployments.

In addition, we need to note that MAP will be more intelligent than ARs in
HMIP, and thus the MAP-based Handover will be preferred to the AR-based one
(i.e.,
as FMIP) by the operators.

We still have many things to do for Fast Handover over HMIP networks,
as some of them are listed in the "further considerations" of the F-HMIPv6
draft. Dependng on the specific choice for each of these considerations,
the design of F-HMIPv6 could be done in various ways.
Do you have any flavor for such choices, and any additional considerations
on F-HMIPv6 ?

Seok J. Koh