Subject: [AAA-WG]: Mobile IP Extension Unresolved Issues

From: Pat Calhoun <[email-masked]>
Date: Mon, 30 Apr 2001 10:33:26 -0700

All,

While re-reading the Previous-FA-xxxx thread, and from my posts earlier today,
it is obvious that there are some unresolved problems in the Mobile IP
extension that really need to be handled prior to sending out the next
revision of the spec, and this MUST happen prior to the interim meeting.

Here is a quick proposal, and I would like to setup a conference call by
all interested parties for next Tuesday at 9am Pacific. I will send out
the necessary conference info. Ideally, though, I would prefer to have this
call setup for tomorrow, but I realize that I have to provide adequate
preparation time for people to drop what they are doing, and get on this call.

Could people interested in this call please respond back directly, and then I
can see if we can move this ahead.

So my proposal is as follows:

When a mobile is handed off to a new Foreign Agent, the FA would use the
Context Transfer protocol (or the MIP FA blob) to authenticate the MN-FA
auth extension. This does NOT require *any* AAA involvement, and reduces the
complexity of the protocol.

btw, if we are to do this, then we could also easily include the Session-Id
in the context transfer, or the FA blob.

Then, while it is forwarding the Registration Request to the Home Agent,
it also sends an HAR to the AAAF (which will make its way to the AAAH). This
message DOES NOT include a Registration Reply, and has something in the
message that identifies itself as an update of FA only. The AAAH would
update its table, and return a successful AMA to the AAAF, and FA. 

So this updating of the AAAH does not add any latency to the registration
process and reduces the complexity of the protocol.

Note that the only caveat here is that we are relying on context transfer,
which is just starting its requirements, or on the FA blob, which is not a
MIP WG document.

Comments?

PatC