Monitoring wireless downloads at my home?

Hi all,

I'm a houseowner and I rent out rooms to college students. I provide them with free wireless internet. I set up the router to allow wireless network & set a password.

Now the problem is since there's only 1 network to be shared among 6 people, I told them to limit their downloads. However I suspect some of them maxing their download speed and leaving the others with little to work with.

I can see DHCP Clients List by accessing router as admin.. but I need a program to tell me which computer is downloading how much (download activity). Any recommendations for such program?

 

pfsense would be a better router project, but you can also monitor with smoothwall.