setting up a server

[joey_2-fitty]

Sorry but i just cannot get a server up and running i setup my argfiles then set up a batch file and it all functions properly and i can join and play on my own server just fine but when my friend tries to join it says WSAECONNRESET i did forward my ports to 19800 to 19800 on UDP protocol and i Allowed mx simulator and mxserver through my firewall. What am i missing causing it not to work?