This is the SSH part where you connect to the remote system and send a local port back to you:
ssh -L 5900:localhost:5900 -p altsshport email@example.com
What can you do with this?
You can run a service on your remote system like this:
x11vnc -display :0 -localhost
On newer Xubuntu systems, you might have to do this script. It will make it easier to start.
#!/bin/bash x11vnc -display :0 -localhost # Include this at the end of the line for 2/3 scale # -scale 2/3
Then, you can vncviewer to your local system:
vncviewer -bgr233 localhost
Voila! Your remote system VNC over SSH in 8-bit display inside an encrypted tunnel!