[lug] QoS for multiple users

[Ben]

I've got ~10 computers sharing an internet connection. When someone 
downloads something, that download gets 100% of our bandwidth and the 
internet slows to a crawl for everyone else. Can QoS fix this?

May setup is:

10 computers on a router     ->  dumb firewall box    ->               
ActionTec -> Internet
192.168.0.*                        192.168.0.1->192.168.2.2            
192.168.2.3 -> *.*.*.*     

 Ideally, I'd like to do QoS on my ActionTec, but potentially I could 
set up a linux gateway router with QoS. The dumb firewall box is a 
little Netgear with no QoS, etc. So the actiontec sees all its 
connections coming from one ip (192.168.2.2) and cannot do IP-based QoS. 
But I don't want to give ip-based priority anyway. Or port-based.  I 
want the connection using the least bandwidth to get the higher 
priority. So if there are N connections, they equally share the 
bandwidth. If there a recommended way to do this?

Thanks,

Ben