X Window Port Forwarding Scenario
If you enable X11 port forwarding in a tunnel profile, when you start the tunnel, the Connectivity Secure Shell engine requests X forwarding when connecting to the Secure Shell server. If the server supports X forwarding, it runs an X11 proxy on the remote host. The $DISPLAY variable is configured so that initiated X applications connect to the X11 proxy, which sends the connection through the tunnel. What is displayed on your desktop is a terminal window from which you can run commands.
|The workstation is not limited to using the TELNET protocol to launch the X Window client on the server machine. It can use any other startup method, including REXEC, RSH, and RLOGIN.