Below possible options for troubleshooting inbound telephony
Inbound number (DID) not bound to correct Distribution Group
Check your Distribution Group IP address settings in Voice Management App.
Firewall not configured for CM inbound trunk IP addresses
Inbound traffic is routed from our dedicated inbound platform. Please allow incoming traffic from:
InOut00 (Legacy platform):
- No correct response to SIP OPTIONS keep alive messages
If a 404 error No Route To Destination|No More Destinations error response is received. Our platform is sending so called Keep Alive messages via SIP OPTIONS message which need to be acknowledged by a 200 OK from customer PBX instance. This is the principle by which our gateways check if the inbound trunk is still available.