Despite having set this on the router (a balance 20) it does not seem to be forwarding ports to my phone system. 188.8.131.52:4001 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)
Serial number 1925-6C40-FEEE
Remote assistance is activated.