If what you're trying to do is connect to a remote host inside a local network, that network should have some form of NAT (Network Address Translation) installed to make the remote host (or some TCP ports of it) visible to the outside world. There are various NAT systems, but all of them work replacing public addresses with private ones. Sort of like a proxy, but at a TCP/IP level (i.e., the system is transparent to the endpoints of the connection). Look for NAT on your web searcher. Generall, NAT systems are managed and configured by the network administrator, so if he hadn't made public the remote host you're trying to connect to, there's litle you can do from the outside. Joaquín M López Muñoz Telefónica, Investigación y Desarrollo