Network Ports
From TSG Library of Knowledge
To host multiplayer games and sometimes even to play, ports need to be open. Go to PortForward.com and follow the guides. However, not only is the make and model of your router important for forwarding ports, but many times DSL users will often have a modem that has router capabilities (called a modem/router combo.) In this case, the user will need to forward the ports in the DSL modem/router combo using the WAN (Internet) IP of the second router. For instance, if the setup is like this: DSL modem/router>router>PC/console, then in the DSL modem/router, the ports will need to opened using the WAN/Internet IP of the second router. Then forwarding can be done in the second router using the computer or console static IP address.

