Add the VPN client/server setup to the advanced menu, the x50-5g appears to have sufficient ram and cpu to run it, as the hardware specs look similar to my x60 which does have the vpn service.

I have the deco X60 and read that firmware 1.2 onwards supports vpn, I have firmware 1.5.3 but there is no option for VPN of any kind in the menu configuration, how do I get this enabled to use?