could not connect to server error

[jamz]

If you don't care about your server appearing on the masterserver list, you just need to get your friend to type:

[SELECT ALL] Code:

/connect xxx.xxx.xxx.xxx

where xxx... is your external IP address, provided:
1) You're running the server on the default port (28763)
2) You've forwarded ports 28763 AND 28764 - *UDP* - to your local IP