The comcast is the modem. When you hook it to the trendnet, that's the wireless device. Your computers will talk to the trendnet, the trendnet will talk to comcast.
The trendnet model that I got is : TRENDnet TE100-S5 5-Port Ethernet Switch (5 x 10/100Mbps Auto-MDIX RJ-45 Ports). My boyfriend said this is not wireless & it will not work. Do you agree? I just want to make sure before I I try to set it up.