Try using the RUNNER program (mohadmin.com) to configure your game.The things you can change to improve performance are maxrate, which i suggest you set to 2500 and hunkmegs which you should set to 16M. If your server is behind a router you will need to open the game ports or place the server in the "DMZ"so it is open to the Internet.
Now go to your game machine and try to join a LAN game. Is your server listed there?
**Practicing the dark art of turn signal usage since 1976.**