Re: how mobile do we want to be

[avri@psg.com]

On 14 mar 2005, at 12.30, Geoff Huston wrote:

> This sounds like a charter discussion point to me- I'm not sure I 
> heard you raise it in the BOF last week, although mobility was 
> mentioned a number of times in the BOF.

Indeed, and I did raise it several times during the BoF.  Rather 
insistently I thought.  and with some support from others in the room, 
I thought.

The point I raised there, was that it did not make sense to make the 
kind of major surgery we are doing to the IP, the so called stem of the 
hourglass, without also considering the implications and opportunities 
for mobility.  During the years of Multi6, this was out of scope.  As 
we are currently discussing a new charter, a charter for a major change 
to IP, I think it is important to take system motion, or non MIP 
mobility, into account.

> I don't think this is a helpful characterization, nor does it apply to 
> the overwhelming majority of the 160,000 prefixes we see in V4, or the 
> somewhat lesser number of prefixes in IPv6.

At this point, if I understand the mechanisms of MIP properly, this 
sort of movement would not show up in the prefixes.

also when you look at the kind of mobility we expect with portable 
devices (though currently committed to a MIP6 framework) I think it is 
natural to assume that more of the end systems will be mobile as time 
goes on.


> There is a Mobile IPv6 working group, and the place to consider the 
> various aspects of mobility in IPv6 is within that working group.

I don't think so.  The Mobile IPv6 WG is dedicated to a specific 
solution to mobility.  The only solution that seems currently available 
without the separation of identifier and locator.  If, however, we 
change that major assumption (ie. that Locator == Identifier) there 
perhaps additional solution fall out of the split.  And while they have 
an interest in assuring that shim6 does not break their solution, I see 
no reason why the ability of shim6 to support network motion is in 
their charter.  I think they are a WG dedicated to a specific solution.

In this case the opportunity of a new means to support system motion 
needs to be explored.  We had years of exploring the multi6 solution 
space.  It seems to me that we should spend at least a little time 
exploring the possibility that shim6 would offer solutions on the 
system motion side as well.  This is the reason I think that
a. the system and network in motion aspect should not be out of charter
b. that at the very least a design team should be set up as part of the 
proposed WG, with a specific milestone, to explore the implications for 
systems and network in motion (ie. non MIP mobility).

> To re-noodle over their work in shim6 is not entirely a helpful 
> direction here.

As I argue above, this is not a re-noodling, but a different way to 
look at the network architecture.  I think it would be irresponsible 
for us to not do an analysis of the implications of such a major 
architectural change.

> Perhaps a more helpful starting point in terms of scoping this work is 
> the architecture draft prepared in the nulti6 context 
> (http://draft-ietf-multi6-architecture.potaroo.net) (and in the 
> context of this area of locator switching and the concept of a 
> dynamically changing locator pool perhaps section 6 is a good starting 
> point)

It is good as far as it goes and is a very informative document, but it 
does not explore non MIP mobility.  I beleive this needs to be explored 
as part of the chartering effort.


a.