How can I give SH4 back to UBI because multiplayer don't work yet?

[diplomatic]

A game that can't played online is worthless.
The most people have not used a router - only a modem - but starting a session is not possible.

I have no router and made all port-exeptions in my firewall, but nobody can connect (I don't block popups set my explorersecurity to medium).
I have the suspect that you can only connect with the IP of your first login.
I talked with the people hosted a game - they had a static IP or were the first time online.
The most people get a dynamic IP from their provider. The people didn't manage to host a game despite the fact they are not using a router.
(I don't want to play it offline!)