Ok, I downloaded Gamespy Arcade, and Tunnel. Here is my situation:

I have my Xbox, and my cable modem. My Cable modem is hooked up to my Ethernet card in my computer. Here is the link to what I need help from: http://www.gamespyarcade.com/support/tunnel_xbox.shtml

Near the bottom, it has options as to ways to set it up. From the info I gave you on how I have my modem hooked up, which would be best for me? PLEASE HELP!