Hi Arran
I have trouble.would you please send me codes?
I don't know how those support adsl do ? when users are online during all the 
days and there is limitation on the traffic amount?  

It's possible even if the NAS doesn't support PoD, so long as the NAS 

supports the 802.1X mib, you should be able to fire off an SNMP-SET with 

the exec module and force re-authentication. All the required 

information is available in the Accounting Request the server just received.

If you're really having trouble and ask nicely i'll write some example code.

Arran