Connection from outside LAN denied


I have recently setup an Asterisk system (IncrediblePBX) for my own learning and have signed up for a SIP trunk. I have been having trouble getting external incoming calls to show up at the PBX I just hear silence. I have port forwarding for the relevant port 5060 setup and everything is setup for NAT.

Taking my trunk provider out of it and if I make a test call from my LAN using Zoiper and point at my router’s external IP address and port 5060 I have success.

However, if I make an incoming call from outside my LAN (again using Zoiper) and point at my router’s external IP address I get no response. I tried disabling the router and iptables altogether temporarily and this made no difference.

The calls made from my LAN show in /var/log/asterisk/full but the ones made from outside do not.

I wonder if there is a setting somewhere I could be overlooking? Some kind of deny for anything outside the local LAN?


I don’t think the calls are even reaching Asterisk.

It is possible your ISP is filtering SIP at their equipment.