Soul, could you try a concurrent speedtest with a few systems on separate IPs and see how it compares to just running one separately?
I'm curious if all your bandwidth is rated as one for concurrent connections. Since they all come through the same modem then I suspect bandwidth is per modem MAC address, not IP or device MAC address.
My Comcast connection is starting to suck. I pay for 8M/768k and normally only can get 1.5M/348k. The next lan party would have very little shared bandwidth for attendees at this rate
