Screen Sharing - New Port

Question

Hello all.
I live in a house with another Mac user, and we both want to use screen sharing. Unfortunately, our DSL modem is a piece of crap - it won't let me set up port translation. Does anyone know how to change the port that screen sharing listens on? If not, does anyone know a good, straight-forward way to translate a port, without the modem getting in the way?
I have no trouble forwarding ports on the modem (inbound 5900 can go to a specific computer on 5900), but I can't have it translate (inbound 5950 can't go to a computer on 5900).
Any suggestions?

Answer 1

Not quite. In your example, you established that port 7777 should be used on the local client. sshd opens a socket on the local client on that port, listening for a connection. You also told sshd that port 5900 is actually where you need the packets to go once something connects to port 7777. When you connect to 7777, sshd sends/forwards all those packets over its secure channel (a TCP connection on port 22) to the remote host, then makes the packets go to port 5900 on the remote.
So the actual transfer of packets is done over the tunnel. You can, as you say, change that port at will.
At least, that's how I understand it to work...