I've been trying to get the commandos 2 multiplayer working with a friend of mine, but thus far with little success.

I've got the ports forwarded and an there should be no interference with the windows firewall either.
When trying to go via direct ip he is not even able to see my game in the lobby, on the other hand when doing so with hamachi, he is able to find the game and to connect but the game it self lags extremely to a degree of almost freezing.

does anyone have an idea what the issue might be? help would be greatly appreciated