Testing your connectivity
To debug your server, checking that all the net threads are fully functional and working, you can use EnEsCe's Port Setting Tester. More information on it can be found in this topic.
This is the only efficient port tester around due to the fact that EnEsCe has access to Soldat's server source code, which means he knows the encryption used and therefore can test in-game connectivity. This is also why you'll see a player named [eC] Test join your server as a spectator if everything goes OK, and then ping timeout.