[klem]

Just to be clear....

1. You have given your friend your ISP's IP and Port number (usually 27016) and your firewall is open.
2. You have gone into Multiplayer... Server.. and clicked on Net to check/set your Port number to 27016 ***, clicked Apply then named your server and given it a password (if you want to keep everyone else out) and clicked on OK to created your Server
3. You then clicked on Multi... Dogfight and highlighted your preferred mission and clicked Select (Single missions and Co-ops won't play over the web). Mission should load to map room.
4. Your friend goes into Multiplayer... Client and has selected Direct Connect, entered your IP and your port number and clicked OK (he should see loading screen then "Waiting for Battle")
5. You clicked on Start Battle (mission loads for your friend)
6. You both pick sides etc.

*** I don't know what you will see in the local IP field as I am behind a router and it shows my local network address.

You can reverse 4 and 5 but, if your friend is slow to join, the battle will have been running for however long it takes him to join.