mumm..... I think you have to make sure which IP address you are using for remote connect, e.g 192.168.x.x or 10.x.x.x, those are for locally (LAN), for the WAN IP address more like 206.13.64.12. something like that. Since the LAN IP address is using for local only. If you use the WAN already, open the port become DMZ zone and try, if you can remote connect it, that's mean is firewall issue, if not, then should be something else.