wireless modem / router monitoring software

I’ve recently upgraded to a new Belkin 4 port wireless router modem. The hardware comes with built in management utilities that allow filtering by IP, mac address etc but no actual usage report or bandwidth limiting. Now the student we have staying with us is connecting laptop (which is ok) and downloading mass files seemingly hogging all the resources of the bandwidth. can anyone suggest some software that will allow me to monitor the amount of data being used by any IP addresses connected through the modem and preferably limit download speeds? (and yes i know get rid of the student would be the easiest solution!)