I have 7 computers that are use for Internet access. I also have several wifi access points. I would like to control the Internet use and charge for it.

The idea would be to redirect every page to a login page so that my cliente would use an user and password. The user and the password would be as pre pay cards. The user should only a limit use of time of the Internet resource: half an hour, two hours, etc..

Is there something like this. I would like to use the same software to control de wifi, as any other computer on my network.

In the next few days a I would receve an old computer that I want to use as my firewall. I would like to use this computer for this purpose.