Yeah, it's impossible to do anything about a stateful firewall to get p2p connections.

It's a shame because if we could only get over stateful firewalling we'd be one step closer to the impossible task of using voice chat in console video games.

Right now they don't have that of course and the only hurdle is "NAT Types" which, as we all know, is a much easier problem to solve for the average person...

(this was sarcasm, if it wasn't clear).