For Xbox with EarthLink: If you wish to connect the XBox to the Internet via your Internet service, you will need an Ethernet cable to establish a connection. You will also need a second NIC or a hub for the XBox game console. At this time, only one IP address is available per account. In order to use your game console, you will have to disconnect your computer from the cable modem, connect your game console to the cable modem and reboot your cable modem.
For PS2 with Earthlink: If you plan to use the computer AND the PS2 simultaneously, you will need to purchase a NAT router.
For PS2 and XBox with TWC Internet: You will need an Ethernet cable to establish a connection.