Despite having set this on the router (a balance 20) it does not seem to be forwarding ports to my phone system. 104.159.226.66:4001 should bring up a login page for an NEC SL2100 system.
It was working and port forwarding a couple of days ago. I tried rebooting it (no change)
A network capture from the Balance reveals that ports 4001 and 4002 are not reaching the WAN interface of the router. You can do a network capture from the Balance after logging in by typing in this address to get the support.cgi page:
http://<Peplink’s IP>/cgi-bin/MANGA/support.cgi
I would contact your ISP to see if they are blocking inbound ports.