I know that (on netgear routers at least), you can't do a remote WOL by port forwarding and sending the magic packet from outwth the LAN (can't remember the exact problem but it's something to do with broadcasting the magic packet to the whole subnet not being permitted) - however the netgear router itself has a WOL function, so you can connect to the router on it's web GUI (or ssh etc.) and WOL using it's own utility. Likely oher routers will have similar functionality?