Pretty sure I know the answer to this, but it doesn't seem like the CGM4140COM Technicolor Xfi gateway supports multiple game consoles playing the same game, all at the same time?
My $50 Netgear router can manage this through setting static IPs and port forwarding, by the way. Can't figure out a way to duplicate that with the Xfi gateway. One device, sure. But multiple? So far no luck.