Re: [RRG] Re: Supposed impossibility of scaling for mobility

[Scott Brim <swb@employees.org>]

Excerpts from William Herrin on Wed, Mar 12, 2008 05:30:38PM -0400:
> And for the record, I take my laptop back and forth to work every day.
> You probably do too. When I do so, it travels between and through
> networks which are administratively and topologically distant. It
> would be awfully nice if it could keep its "number" the same way my
> cell phone does without the nasty routing inefficiencies that had to
> be introduced into the telephone network... Nice enough that I could
> see buying service from companies who could do it in preference to
> those who couldn't.

You elicit a couple of questions here.

  - What your cell phone provides is "session continuity".  That is,
    you're talking and as you change locations you can continue
    talking.  I assume that when you go to your office you close your
    laptop, and you don't have any sessions continuing.  This is
    sometimes called "nomadicity" as opposed to "mobility".  What
    exactly are you looking for?  

  - Even if you want full mobility, why do you assume the only way to
    get it is to have the same IP address the whole time?  See HIP and
    higher layer session continuity mechanisms.


Excerpts from Robin Whittle on Thu, Mar 13, 2008 12:35:56AM +1100:
> Multihoming service restoration and portability both can be done
> best by the end-user deciding which ETR to use, in their own way,

Why do you believe that?  Most end users only care about their
subjective experience, and if they have to be involved in the
complexity of how it's delivered, they feel burdened.

> and having fast control of the world's ITRs to implement that
> decision.  

An ITR will maintain state on millions of flows going through it, as
to which ETR it wishes to be sent to?



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