I started to have issues with incoming SIP calls. My provider is sending the invites but my sip server is not responding on the invites any more. Out going call are working just fine.
On the the server with sip debugging on I don’t see any incoming messages from the provider.
Did someone experienced the same issue? Can someone point me in the right direction of the root cause?
This looks like an iptables issue, especially if you don’t see the OK corresponding to the REGISTER in Asterisk. Restart the firewall, make sure the provider IP is not banned in intrusion detection.