Calls Cannot Be Set Up When the U1980 Is Connected to another PBX and Are Rejected After 2s

Symptom

When the U1980 is connected to a peer PBX, calls cannot be set up and are rejected after 2s.

The following figure shows the network diagram.

Possible Cause

• The SIP trunk is faulty.
• A fault occurs at the peer end.

Solution

1. Check the SIP trunk.

   Run the show peercompant command. It is found that the commstate value is OK. The SIP trunk works properly.

2. Capture SIP data packets. It is found that the peer end returns the 401 message, as shown in the following figure.

   
   

3. Use the UCMaint to capture data packets on the U1980. The following figure shows the information found.

   
   

    

   Based on SIP log analysis, the peer end returns the 401 message for the 200 OK message to release the call. Therefore, you must confirm with the peer end.

4. Confirm with the peer end. It is found that the peer end uses open source PBX software, which poses high security requirements. The peer end forbids calls through anonymous SIP trunks.
5. Ask the peer end to allow calls through anonymous SIP trunks. The fault is rectified.

Conclusion and Suggestion

Currently, Huawei SIP trunks do not support authentication. When encountering trunk faults, solve them together with the peer end.