how to tunnel remote ubuntu linux system full destop with Xephyr

> install xfce4 onthe remote system :
ssh user@host
sudo apt-get install xfce4
logout

> isntall Xephyr :
sudo apt-get install xserver-xephyr

> start Xephyr :
export DISPLAY=:0.0     # make sure that the display is set to the host 
Xephyr -ac -screen 1280x950 -br -reset -terminate 2> /dev/null :1 -keybd ephyr,,,xkbmodel=evdev &
export DISPLAY=:1.0     # set the display to the Xephyr
ssh -YfC -c blowfish user@host xfce4-session 2> /dev/null