Why to use the remote sysrq?
Sometimes a remote server hangs and only responds to icmp echo
request (ping). Every administrator of such machine is very unhappy
because (s)he must go there and press the reset button. It takes a long
time and it’s inconvenient. So here is a solution. Use the Network
Magic SysRq and you will be able to do more than just pressing a reset
button. You can remotely sync disks, remount them read-only, then do a
reboot. And everything comfortably and only in a few seconds. 
Marek Zelem : IP Tables network magic SysRq function 0.4
PS: Nu l-am testat inca.