A guest house which wishes to share adsl connection with several rooms - what I'd like to achieve is that a person plugs in their laptop computer in a particular room, that they can be allocated an ip address (DHCP), or that the outlet is plugged into a managed switch (static ip) - and that their bandwidth / time online can be monitored - set to predetermined parameters (eg number of hours - or between hours of... / Mb downloaded etc).

I am used to ipcop / smoothwall - but not sure how to go the next step with monitoring / traffic like this for individual computers on network.

Any ideas - or can anyone point me in the directon of some good documentation?

I would always resort to my tcpd and service logs if all you want is time of connect and lenght of time.

There are bandwidth monitoring tools available.