Analyze the reason why a call to an IVR extension failed

Background：

We have a customer tell us that only one number of their external DID number can be dialed. Other external numbers are immediately hanged after dialing. The customer uses 3CX connected FXO port gateway to make outbound phone calls.

Solution:

Because not all numbers can’t be called in, We decided to check the gateway first. We checked the DID bound in the gateway and and also checked the routing table and network settings. There is no problem finding the gateway by looking at it.

 

Go to 3CX Control Panel – SIP Trunk to checked the DID number that added in the SIP trunk. The relevant DID numbers have been added to the DID column. This indicates that there is no DID number mismatch issue between the gateway and the 3CX.

 

Then we go to the 3CX Dashboard – Activity Log and set the log level to verbose. As shown below.

Dial the number that cannot be called again, reproduce the problem, and filter the virtual number of the SIP trunk we use in the log activity interface. We found that the log shows failed to reach ivr: 8000, reason Not Registered. As shown in the figure below, this indicates that our IVR extension is not registered.

The IVR extension is not registered, which indicates that there may be a problem with our IVR service. We can see that the servers and system extensions are all in red when we go to our dashboard PBX status interface.

Clicking on the system extension, we can see that the 8000 extension is not registered. After clicking into the server interface, we found that the status of the 3CX PhoneSystem 01 IVR Server is stopped. We need to select this server, then click Start to start the service. Then we called the DID numbers, It is ok.

Why is there a number that can be dialed? Go to the 3CX Control Panel – inbound rules, we can found that the DID number that can be successfully dialed was bound to our ordinary extension, and the other DID numbers are bound to the 8000 IVR extension, 3CX PhoneSystem 01 IVR Server Stopping does not affect the use of other regular extensions.