US Patent 7602784 Method and apparatus to permit data transmission to traverse firewalls

Currently data transmission over the Internet between two client computers where both client computers are protected by firewalls is problematic, since firewalls block incoming packets. A method is provided for permitting packet based data transmission between a first client computer C1 protected by a first NAPT or NAT firewall and a second client computer C2 protected by a second NAPT or NAT firewall to traverse the first and the second firewalls. The method can also be applied to other devices, such as routers, using NAT or NAPT.