Subject: Re: An approach for detachable interfaces.
To: David Evans <dfevans@bbcr.uwaterloo.ca>
From: Bill Sommerfeld <sommerfeld@orchard.arlington.ma.us>
List: tech-net
Date: 11/05/1999 16:00:39
>   I don't think that he's arguing that providing that functionality is
> fundamentally broken.  But a straightforward implementation of that
> functionality leads to headaches when you want to do the replacement, have the
> new card be considered the same interface as the old, but provide new
> parameters to this interface upon presentation of the new card.

Can you be more specific about what sort of "parameters" you're
talking about?  i can't see any scheme which allows for userland to
get an event on card insertion not also get an event on card removal,
and should you desire that behavior, the "card manager" daemon can
deconfigure the "zombine interface" after the card's been detached.

Given what i'm proposing, plus appropriate support for userland events
on card insertion/ejection and carrier detect and carrier loss, I
think you can implement just about any policy you want in userland.

Is there really a meaningful difference between

	ep0 with parameter set A at home
	ep0 with parameter set B at work.

and 

	ep0 with parameter set A at home
	ep1 with parameter set B at work.

if at most one card is ever inserted at any given instant?

					- Bill