Subject: Re: [MOBILE-IP] Comparison of Fast Handoff and Proactive Handoff

From: James Kempf <[email-masked]>
Date: Thu, 13 Jul 2000 15:36:28 -0700

>However, I think this discussion is hiding  the real issue. The fundamental
>difference between our proposal and yours is who has ultimate
>control over handoff, the network or the mobile . We are proposing that the
>network is in a much better position to perform functions such as load
>balancing, QoS determination, etc, especially in 3G-type networks, and
therefore
>the network should be the final arbiter of where the mobile is placed. In your
>proposal, the mobile gets the final say over whether it will or will not take a
>handoff, so the network's decision could be overridden.
>

I think I overstated my case here. Rather than "ultimate", I think I
should have said "principle".

There is nothing in our proposal to prevent the MN from rejecting
the advertisement sent to it by the new FA. If it does, it risks
losing service once the old FA signal fades. The MN could perform
an FA solicitation to try to find another new FA, but if the network
operator, as a policy decision, decides not to allow an FA to respond
to the solicitation, then the MN is essentially hosed.

Sorry.

                jak

---

From: "Jari T. Malinen" <[email-masked]>
Date: Thu, 13 Jul 2000 22:12:05 -0700

> to the solicitation, then the MN is essentially hosed.

The discussion of proactive vs. reactive approach has brought up the
fact that it is not easy to merge the two conflicting principles in the
L2 systems vs. L3 protocols whose interaction is attempted with
these relatively simple protocols. On the one hand, features known
in the complex telecom systems often require tight network-controlled
approach, on the other hand, the layered Internet protocols usually
attempt to solve issues one-by-one separating concerns, with
independence of the communication endpoint, and also counting on
abundance of resources. Claiming that one is better than another,
in particular when the L3 protocols should _also_ work with other
technologies, leads to problems.

If we really start to consider the many issues in resource control,
traffic control, QoS, etc. we might see that the complexity of the
one protocol might, after those additions, grow beyond reasonable.
The separation of concerns that has worked quite nicely for Internet
protocols should not be abandoned, instead, when experimenting
with the idea of introducing these telecom-inspired features to the
L3, we might want to consider a more flexible, frameworked approach.
The we should have something where we have components that
provide smooth handoff support for a combination of approaches,
separated from other issues and we could address each issue
separately.

Regards,

--jari

Jari T. Malinen
Nokia Research Center.