Tcpquota monitors and debits users depending on their online time (dialout). the program is made for those who have a local network with a server that also functions as an internet gateway (among other things).

the server runs diald, for example, which does the actual dial-on-demand, and this package which debits each user, whether from the server or from a masqueraded host (program includes masquerade code).

all a user from inside the gateway/firewall has to do is run the command 'openhost', and the hostname and username is masqueraded and debited according to the time they spend calling out.

when user runs out of money (pre-paid amount), the firewall will close the connection for the user and it will stay closed until the user deposits more credits to the system.