We have a Linux-based router which is currently working fairly well, but our network only has a 1.5 mbps incoming connection. The network is small, but during high load periods some systems can end up dominating the bandwidth. For example, a client downloading a file can easily saturate the connection leaving everyone else with barely any access to the outside world.

Naturally, I'd like to fix this. I believe a combination of iptables rules and tc is in order, but I have no idea how to go about distributing the bandwidth evenly across the clients.

It would be nice if there was a way to divide the bandwidth only across clients that are actually utilising the connection as well, rather than hard limit each connection to (bandwidth / number of clients).