I have a device which I can telnet to and it will bring me a shell,but
only one session is allowed just like console with serial cable
connected(if you try 2nd connection while first one is still alive, the
2nd will fail). what I want is to make a TCP tunnel, one end of the
tunnel is my device and the other side is listening on my admin box,
when I want to access the device I just need telnet to admin box.

What I want is to log everything my device send out whether a
connection is there or not. Is there anyone can help me?

thanks a lot.