Re: on the point of mobility & multihoming

[Brian E Carpenter <brc@zurich.ibm.com>]

below...

Kanchei Loa wrote:
> 
> > >>They have certain similarity that if we are going to solve mobility
> > >>issue in a way different from MIPv6, which is hopeless, minor details
> > >>of M6 design will be affected.
> >
> > > My opinion, for what it's worth, is that we're not out to solve the
> > > mobility issue in Multi6. I don't think we want to advertise that
> > > we will work on mobility, as mobility has out of scope.  If we are
> > > clever, the solution for multihoming will be useful for mobility.
> > > However, I would not like multi6 to get a storm of drafts about
> > > mobility when we are chartered to solve multihoming.
> >
> > I fully agree with you.
> >
> > Proposals from those who half understand the relationships
> > will be really annoying.
> >
> > Thus, in my proposal, details of possible mobility solution is
> > dropped, though minimal explanation on why a bit is reserved is
> > given.
> >
> >                                                       Masataka Ohta
> 
> In my opinion, you just hit an important issue of multi6 architecture, which
> this WG is supposed to work on first. If we take Dave Croker's scenario
> (suggested by Geoff Huston) and generalize it, the problem space is the same
> as depicted in Geoff's slide (page 3) of "An Architectural View of Multi6
> proposals" except that the solid line (wired fixed connection) between the
> exit route and ISP is replace by dotted lines (wireless dynamic
> connections).
> 
> In this architecture, mobility is just a special case of "dynamic ad hoc
> multihoming", which has timing restriction on updates and discovery. (You
> don't have to call it mobility if that is more IETF political correct). In
> Dave's scenario, from IP network's point of view, there is no difference
> between a laptop sitting on a bench switching among ISPs because of
> interference and a laptop sitting in a car that is moving back and forth
> among ISPs.
> 
> Should multi6 architecture encompass wireless connections between the exit
> router and IPS? Or, Dave Croker's scenario is too far away in the future to
> be included in multi6 architecture, which has been focusing on traditional
> IP multihoming with fixed connections only? It is up to the WG to decide.
> But the architecture document should spell out the rational choice. The
> "uncomfortable" wireless issues won't goes away if we just choose to ignore
> them or call it something else.

Actually, it isn't up to the WG to decide. We are chartered to deal with
_site multihoming_. That is definitely a different problem space from host
multihoming in the form of ISP roaming.

(Also, I don't see what wireless has to do with it. If I sit in front of two
Ethernet plugs leading to two ISPs, and move my connector from one to the other
every two minutes, the problem is the same - but it is *not* site multihoming.)

   Brian

   Brian