Serious problems with "rescan networks on wakeup" feature.

[John Watlington]

On Mar 2, 2008, at 7:49 PM, Thomas Tuttle wrote:

> Hi.
>
> I just upgraded to joyride-1738, and the new feature that rescans for
> networks when the laptop wakes up is causing a lot of trouble for  
> me.  I
> often leave long-running connections such as IMAP or IRC open.  Before
> the change, the laptop would wake up, the card would reassociate, and
> there was a good chance that my connection would still be up.   
> After the
> change, the connections are almost always dropped, even if I just  
> turned
> the laptop off for a few seconds.
>
> What would be *great* is if it waited 5 or 10 seconds, tried the
> existing connection, and then restarted scanning *if* it wasn't  
> working
> anymore.  The lag isn't that bad, and it makes the experience where  
> you
> just closed the laptop a minute ago and are still on the same network
> better.

The problem we have is the following:

A student is using the laptop away from school/infrastructure, and is in
simple mesh mode.   In this mode, all service discovery and collboration
is multicast.    The student puts their computer to sleep (by closing  
the lid)
and goes to school.   Once they arrive at school, the last thing we want
is for their laptop to try to use simple mesh --- it trashes spectrum  
and makes
the school network not work, plus they won't see any of their friends  
that
are (properly) connected through the school presence service.

If we naively followed your suggestion above, the laptop would of course
discover that the previous network state (simple mesh) was fine, and it
would never discover that there were centralized services available.

This reply is intended to spark discussion about better fixes.

For example, how about only rescan when the laptop was in simple mesh
mode when put to sleep, or if an attempt to reestablish the existing  
connection
fails ?

wad