Subject: RE: CT reliability model was RE: [seamoby] [Issue] Support for Mu lti- Phase CT

From: [email-masked]
Date: Thu, 12 Jul 2001 11:22:09 +0300

Hi Pat,

> I think that two phases are needed, regardless of the MTU size. I
> believe that in order to achieve a seamless handoff, it is necessary
> to transfer time sensitive context blobs as soon as possible (e.g.
> header compression, L2 keying info, L3 SAs). These are necessary
> in order to exchange packets with the mobile, but there may be other
> time sensitive blobs that I haven't thought of as well. 
> Non-time sensitive blobs (e.g. accounting session id) are not needed 
> to send/receive packets and therefore do not need to be sent right away.

I think that discussing of phases is leading us to a dead end.  What
we need is the following behavior:

1) Ability to send time-critical context
2) Ability to discard stale context
3) Ability to synchronize the context transfer with an additional
   procedure (like a handover)
4) Ability to use different triggers to start the transfer of some 
   contexts.
5) Ability to acknowledge the transfer of some contexts.
6) Ability to group or send seperately contexts.

My feeling is that when we group the behaviors, we may get the different
phases - but I think that there may be more than just 2 phases of 
CT.  Actually, the above behaviors may depend upon the type context
being transfered.  As we have not identified all the possible types
of context to be transfered and all of the situations, I don't
believe that discussing the phases (or modes) of context transfer
is a good idea currently.

I'm writing up an issue on this right now.  I'm happy to contribute
text.

Comments?
John

---

From: "Henrik Levkowetz" <[email-masked]>
Date: Thu, 12 Jul 2001 21:38:58 +0200

Ooh, well put, John.

	Best, Henrik