I've a full nat cone connection (fastweb) so its MAN (a sort of big LAN) has the same shared public IP for the same geographical area.
It's possible to port forward and open the ports in its router (not configurable in standard manners)? I would play worms4, but I can't :( (I'd change the line but 1) fastweb was the only one avaiable; 2) I'm not the owner of it, so I can't). In windows there's a software - port forward - that sometimes have used to work...