SYSTEM, TERMINAL, METHOD AND COMPUTER PROGRAM PRODUCT OR ESTABLISHING A TRANSPORT-LEVEL CONNECTION WITH A SERVER LOCATED BEHIND A NETWORK ADDRESS TRANSLATOR AND/OR FIREWALL
A system, terminating node, method, and computer program product enable an originating node in a public network to communicate with a terminating node in a private network by sending a non-IP-based message from the originating node to the terminating node, thereby causing the terminating node to initiate IP -based communication with the originating node. Because a client behind a NAT and/or firewall in a private network will generally be able to connect and establish a TCP/IP session to a server in the public network, this improves the ability of the originating node to communicate with the terminating node whenever desired. Once the IP -based communication session is established, the two nodes can exchange data in both directions until the connection between them is closed by either node. As such, unmodified client and server TCP/IP applications are able to traverse a NAT/firewall, without the need for configuration of an intermediary node.