Subject: RE: [mobile-ip] WG Last Call: draft-ietf-mobileip-reg-tunnel-06.t xt

From: Annika Jonsson <[email-masked]>
Date: Mon, 22 Apr 2002 16:39:22 +0200

Hi

see my comments below...

>Now:
>Here is the conflict:
>
>A Foreign Agent which supports regional tunneling management MUST support
>registrations according to Mobile IPv4 [9]. In other words, this FA MUST 
>set both the 'F' and 'I' bits.
>I hope you agree.

Yes.

>The problem is that you override the requirement of RFC3220 " Which is a 
>MUST"
>by allowing the FA to set the only included care-of address to ZERO.
>
>A legacy Mobile Node which does not support regional tunneling management 
>will
>not be able to register with this FA.

Correct.

>Please let me know of what you think?
>Thanks for consideration.

You are right. If a FA is configured not to address any CoA, it will not 
support "pure RFC 3220" MN:s. It is up to the administrator of the network 
to decide if this is OK or not. We want to support backwards compatibility, 
but we also want to support optimisations, and that's why the draft 
includes both options.

/Annika

>Ahmad Muhanna

---

From: "Charles E. Perkins" <[email-masked]>
Date: Mon, 22 Apr 2002 11:18:38 -0700

Hello Annika,

I would like to add something to your comment...

> but we also want to support optimisations, and that's why the draft

The care-of address offered by a foreign agent is almost definitionally
something that is configured by an administrator.  If the administrator
configures the foreign agent to not have any advertised care-of addresses,
then that administrator has already decided not to support RFC 3220
mobile nodes.  This would, for instance, enable local network support
for Mobile IP but with foreign agents that only have private addresses.

Thus, it is not a way to disable existing foreign agent functionality.
It is a way to offer new foreign agent functionality in situations
where RFC 3220 foreign agents might impractical.

So I'd say that's somewhat different than an "optimization".

Regards,
Charlie P.