Your Netcomm has an internal firewall, that could be what's stopping your connection. I had an NB 1300 & had to port forward. Try that. Here are the instructions.
Port Forwarding for the Netcomm NB1300-ADSL

Don't forget the step of setting up a static IP (it's in the instructions), otherwise port forwarding won't work. LW's listening port, port in the 'manual port forward' box & port forwarded within a router must all be the same number.