Hole punching firewalls is almost as old as NAT itself, but it's still really useful. Got HTTP access? Tunnel a command to the server over HTTP and punch the p

Hole punching firewalls is almost as old as NAT itself, but it's still really useful. Got HTTP access? Tunnel a command to the server over HTTP and punch the ports Of course if someone simply disallows access to the skype servers it breaks this approach, Or having a special NAT setup. All and all hole punching is a cool subject.