Subject: Re: [MOBILE-IP] Regional Registration Questions

From: "Karim El-Malki (ERA)" <[email-masked]>
Date: Thu, 11 May 2000 10:16:14 +0200

Hello Scott

>  I must have missed something. Why is it valuable to have the
>  MN-FA security
>  association common to the MN-GFA association? If the MN
>  moves to another FA,
>  the registration request must still be sent to the GFA to
>  update the local
>  care-of-address (the new FA) so you don't save any
>  registration time by
>  having the keying information at the FA. What did I miss.

I see your point with respect to the 2-level hierarchy model
(GFA-FA-MN). However when using multiple-level hierarchies
one could distribute the key info to all the FAs in the path
to the MN. When the MN moves to a new FA, one could then have
the appropriate intermediate FA send the reply back to the MN
without always going up to the GFA (the resulting Reg'n lifetime
would be what is left from the MN-GFA/MN-HA Reg'n lifetime which
must not be about to expire). This may speed up the handoff
process when a MN is moving often within a multi-level
hierarchical domain.

Cheers
/Karim

---

From: Tom Weckström <[email-masked]>
Date: Thu, 11 May 2000 19:05:49 +0300

Hello,

On Thu, 11 May 2000, Karim El-Malki (ERA) wrote:

Karim. >Hello Scott
Karim. >
Karim. >>  I must have missed something. Why is it valuable to have the
Karim. >>  MN-FA security
Karim. >>  association common to the MN-GFA association? If the MN
Karim. >>  moves to another FA,
Karim. >>  the registration request must still be sent to the GFA to
Karim. >>  update the local
Karim. >>  care-of-address (the new FA) so you don't save any
Karim. >>  registration time by
Karim. >>  having the keying information at the FA. What did I miss.
Karim. >
Karim. >I see your point with respect to the 2-level hierarchy model
Karim. >(GFA-FA-MN). However when using multiple-level hierarchies
Karim. >one could distribute the key info to all the FAs in the path
Karim. >to the MN. When the MN moves to a new FA, one could then have
Karim. >the appropriate intermediate FA send the reply back to the MN
Karim. >without always going up to the GFA (the resulting Reg'n lifetime
Karim. >would be what is left from the MN-GFA/MN-HA Reg'n lifetime which
Karim. >must not be about to expire). This may speed up the handoff
Karim. >process when a MN is moving often within a multi-level
Karim. >hierarchical domain.
Karim. >
Karim. >Cheers
Karim. >/Karim
Karim. >

Exactly, Karim! This has been implemented in the hierarchical Dynamics -
HUT Mobile IPv4 about one year ago. The protocol has also matured a lot
since May 1999. Maybe it would be worth looking at the publications on the
Dynamics web site? ;-)

Regards,
        Tom

--
        Tom Weckström           Dynamics group
                                Helsinki University of Technology
                                [email-masked]
                                http://www.cs.hut.fi/Research/Dynamics/