I think our it staff are after something that they can turn access on and off again every 10 mins during lessons without affecting other rooms.
We use a straight Linux box with IPtables and Webmin to accomplish this. I presume you have IPs assigned to your classroom PCS? If so make an IP Tables rule to allow routing(*1) through the box to the RBC proxy, and a rule to deny access. I then wrote a quick webmin module to execute any script in a given directory given a parameter on the URL string. I then added the command to add/remove the f/w rules into enable/disable scripts - 1 per room. Knock up a simple page that says enable room blah -> link to http://controlsys:10000/modulename/nameofcgi.cgi?exec=addroomblah and disable room blah -> link to http://controlsys:10000/modulename/nameofcgi.cgi?exec=removeroomblah etc... The scripts also set a flag file so you can display if the room is already enabled/disabled. User clicks link, logs into webmin(*2) then the room is enabled/disabled. If that makes any sense to you! Took me about 1 1/2 - 2 days to come up with the concept and then implement test etc. *1 You will have to somehow route all traffic destin for the RBC proxy through the box. I don't know your network so I can't comment on how easy this would be to do. We had to make a new subnet and change a load of config for this to work for us - but only because we wanted: Room control -> our proxy -> RBC proxy. *2 We joined to box to our staff domain using samba so users can use their standard windows username and password. Hope this Helps - if you have any questions or want any of my (bodged) code then feel free to ask! Will