Play online games through a firewall or proxy server
Many games allow you to play multiple player games with other people on the Internet. To do this, game programs need to exchange large amounts of data between your computer and the other players' computers. This data enters and leaves your computer through a passageway called a port.
For games to exchange data, the correct port must be open on each computer that's participating in the game. Some games connect to the correct port automatically, but many games require that you open the port manually for the game to work.
If multiple player gaming seems not to work through the Internet or on a network, your firewall or proxy server might be blocking the port the game uses. Try either of the following:
