Subject: Re: [mobile-ip] questions on fast handoffs for MIPv6

From: [email-masked]
Date: Mon, 11 Jun 2001 10:24:36 -0700

snip for clarity...
===================

here the text i sent in another mail. it should answer your question.

in the mobile controlled handoff case, its the MN which says
i want to move to this particular AR.

>> How does the MN informs this to Old AR when the MN has not "arrived" or not
connected or not exhanged any packets with the new AR?

so here there is no
question of authorization of the newAR to receive MN's
packets.

>> New AR has to authenticate the MN before it can store packets for the MN. If
not, it will opne many issues.

in the network controlled handover, its again some
network entity

>>  can you point out which entity? or Are we going to leave this out of this
draft.

which decides that this particular MN should
be handed over to this AR. there is no question of
authorization of the newAR in this case either.

the newAR also receives a HI from the oldAR protected by
an authentication header. the oldAR receives a HAck from
the newAR protected by an authentication header.

>> I am not interested to reopen the fast handoff and buffering. My concern is,
the scenario where we allow the new AR to buffer packets before the
mobile can attach itself to new AR.

     1. Security issues as pointed out
     2. Ping pong effect - when the mobile is not able to attach to new AR after
Hi-HACK (between ARs). Either the mobile returns to old AR or selects a
different AR. What happens to buffered packets at the anticipated new AR?
     3. Timing issues - How long and how much buffer has to allocated, What
happens if the MN has not attached itself with in the time limit.

     Eventhough above issues have been raised earlier, I like to see them
resolved in this draft.

for various reasons, IMHO even if buffering is good choice we should avoid
buffering packets for un attached MNs.

Barani.

---

From: Vijay Devarapalli <[email-masked]>
Date: Mon, 11 Jun 2001 11:49:43 -0700

I wish you would read the fast handoff draft again. it clearly
says what the assumptions are and what the limitations are. the
draft would answer all your questions.

if you still have these questions after that, lets take them
offline.

Vijay