1. Please determine the game version you are running. This is shown in the bottom right corner of the screen when at the main menu in-game.
2. If you're on game version 1.05 or less, then you'll need to follow the step-by-step I wrote called "Networking and SINS" which can be found linked-to right under the GREEN writing in the OP of this thread .
3. If you and your friend install IMPULSE (download from www.impulsedriven.com ) and update your games to version 1.1 BETA (v1.095) you don't have to forward any ports....etc.
...done.
the Monk