Re: how mobile do we need to be (was Re: how mobile do we want to be)

[Erik Nordmark <erik.nordmark@sun.com>]

avri@psg.com wrote:

> One thing I am pretty sure is that if it is possible to coerce shims 
> into doing dynamic multihoming, i.e. multihoming with movement, then 
> someone will.  Given that it probably will happen, it might be better to 
> design for it.

Avri,

Based on the discussions so far I haven't seen anybody being 
uncomfortable with adding wording about handling a dynamic set of 
addresses to the charter.
And I'm all for it; it matches what I see as being needed to enable 
future optimizations/combinations of multihoming and different forms of 
mobility.

But this is very different than having a charter should say that we 
solve (IP)mobility+multihoming. There are lots of questions and 
different views in the IETF how to handle the "fixpoint" aspect of 
something that moves; whether done using IP routing, DNS name, SIP 
registrations, etc, etc.
And we don't want to try to resolve such disagreements in a shim6 group.
Hence to me it makes a lot of sense to allow the "fixpoint" aspects to 
be orthogonal to the mechanisms for managing the address pairs.

Note that any dynamic multihoming would have applicability limited by 
the frequency at one can change IP addresses and notify the peer of the 
new address(es) without to much packet loss during the roundtrip time. 
Thus, there would still be a need for L2 mobility management for 
handling frequent, local movement without effecting the IP addresses.

   Erik