. . "Thereafter, the bridge proxy server 500 takes data received on port 1, changes the return address to indicate the proxy server 500, and sends the data to user B. Similarly, the bridge proxy server 500 takes data received on port 2, changes the return address to indicate the proxy server 500, and sends the data to user A. Communication Scenarios [0058] When any two systems, such as systems A and B," . .