You have to install a special os on your router to be able to track usage.... the two most popular ones are dd-wrt and tomato.
But it really is worth it... you can also get realtime usage so you know exactly when somebody is using it and can go figure out which person is actually on the computer at that time.
But it really is worth it... you can also get realtime usage so you know exactly when somebody is using it and can go figure out which person is actually on the computer at that time.