Using the Server Activity Log to Identify Why a Call is Not Reaching its Destination

The 3CX Activity Log is an important troubleshooting tool that can help you identify the cause of simple (and possibly not so simple) issues. In this example, we have a scenario where a Director (having extension 100) is trying to call another extension (120), however the call is being transferred immediately to voicemail.

Here is how to troubleshoot such a situation using the 3CX Server Activity Log.

  1. Go ahead and load the 3CX Management Console.
  2. Ask the caller to try and make the call again, reproducing the problem.
  3. Change to the “Server Activity Log” node.
  4. In the “Filter by Extension” drop down, select the extension number of the caller.
  5. Hit the “Apply Filter” button, and the log will be filtered for the logging generated by extension 100 (the extension of the Director).
  6. You will notice that most of the filtered lines will contain logging similar to: Call(C:15). This indicates the number of the call.
  7. Locate the call which the Director made to extension 120. Below is the resultant logging. Remember that you need to start reading the logging from the bottom, up.

    Leg L:15.1[Extn:100] is terminated: Cause: BYE from 192.168.109.1:54445
    [CM503007]: Call(C:15): Extn:100 has joined, contact sip:100@192.168.109.1:54445
    [CM503016]: Call(C:15): Attempt to reach <sip:120@192.168.109.1:5060> from Extn:100 has failed. Reason: Not Registered
    [CM503001]: Call(C:15): Incoming call from Extn:100 to sip:120@192.168.109.1:5060

  8. This immediately hints that the call is not making it through because no phone is registered with the called extension. We need to keep in mind that the above logging is generated by the extension of the caller. Let’s go ahead and filter the logging by the Call ID which contains the logging from both extensions.
  9. We now know that the ID of the call is 15. Therefore, we should select 15 in the “Filter by Call”. Remember to select “All Extensions” in the “Filter by Extension” list. Below is the resultant logging:

    Leg L:15.2[VMail:999] is terminated: Cause: BYE from PBX
    [CM503008]: Call(C:15): Call is terminated
    Leg L:15.1[Extn:100] is terminated: Cause: BYE from 192.168.109.1:54445
    [CM503007]: Call(C:15): VMail:999 has joined, contact sip:999@127.0.0.1:40600
    [CM503007]: Call(C:15): Extn:100 has joined, contact sip:100@192.168.109.1:54445
    [CM503025]: Call(C:15): Calling T:VMail:999@[Dev:sip:999@127.0.0.1:40600;rinstance=f77ac1401bc2d404]
    [CM503005]: Call(C:15): Forwarding: T:VMail:999@[Dev:sip:999@127.0.0.1:40600;rinstance=f77ac1401bc2d404]
    [CM503016]: Call(C:15): Attempt to reach <sip:120@192.168.109.1:5060> from Extn:100 has failed. Reason: Not Registered
    [CM503017]: Call(C:15): Target is not registered: Extn:120
    [CM503001]: Call(C:15): Incoming call from Extn:100 to sip:120@192.168.109.1:5060

  10. The second line of log (from the bottom up) confirms that the call is failing because the called extension is not registered. The rest of the logging shows that the call is being transferred to voice mail, as configured in the forwarding rules for extension 120.

Now that we have identified the cause of the problem from the 3CX Server Activity Log, we might want to confirm that the Extension is not registered from the Extension Status node and the Phones node. Check network connectivity between the PBX and the phone of the extension which is not registered. Check for errors on the phone, and try filtering the Server Activity Log for the logging of the called Extension.

More information on the 3CX Server Activity Log and other examples on how this can be used for troubleshooting can be found here.

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