Beep frequency

xset b vol freq dur

volume: % of max
freq: Hz
dur: ms

Reverse Tunelling and x2x

To control a box behind a firewall using keyboard and mouse on another computer.

On firewalled computer run

ssh -R 22222:localhost:22 user@localcomp

On local computer run
ssh -p -X 22222 user@localhost
In the last ssh tunnel run

x2x -east -to :0