"Rejecting unknown SIP connection from " weird IP address

I’m seeting up FreePBX with SIP trunking from Twilio. It all works except for periodic failures when calling in to the PBX. When this happens I get a recording “all circuits are busy” and the following error is logged:

[2017-09-26 16:25:31] WARNING[17554][C-0000025f] Ext. s: “Rejecting unknown SIP connection from”

I don’t know where this IP address is coming from, since it is not listed as one of the IP’s from which Twilio originates calls. A reverse DNS lookup shows that it is registered in Germany. I thought there might be some NAT problem and I tried various NAT settings on my router, but these all made things worse. I suppose I could just create another trunk for this IP address, since the errors always references this exact address, but I’d like to understand what’s happening --??

Thanks much in advance for your advice.

Matthew Fleming

1 Like

If that is happening when you call into your Twilio number, then call Twilio and ask them what happened to the call that you placed to your Twilio number at 2017-09-26 16:25:31 (or whenever you saw a failed call)?

If that IP address is unknown to you, why do you allow traffic from it through your firewall?

Same problem

This topic was automatically closed 31 days after the last reply. New replies are no longer allowed.