Add this simple script to your node for remote node reboot capability via DTMF command:
http://irlp.kk7av.com/scripts/reboot_node
Put it in your /home/irlp/custom directory.  It requires no user configuration but you will need to make an entry in your /etc/sudoers file which will allow user repeater to access the privileged shutdown command without a password.  Use the visudo utility to add the following line to your /etc/sudoers file:

repeater ALL= NOPASSWD: /sbin/shutdown

After that, you can call the script with a DTMF command.  To do this, you need to add the following to your /home/irlp/custom/custom_decode file:

# call node_reboot script
if [ "$1" = "PP1" ]; then
   $CUSTOM/reboot_node & >&/dev/null 2>&1
   exit 1
fi

That would cause the DTMF sequence, "##1" to call the node_reboot script.  Enjoy!