Low Call Connection Rate After Phones Register with the Softswitch Through the IAD

Symptom

The call connection rate amounts to only 10% when phones register with the SoftCo through the IAD.

• Multiple IADs simultaneously register with the same equipment identity (EID) on the softswitch.
• The network environment is poor.

Solution

1. Use the Wireshark to capture IAD signaling messages, and analyze these messages. The analysis result shows that the softswitch returns a 403 error response message to the IAD INVITE message, which indicates that server recognizes but refuses to execute the request message.
2. Check the data configuration and clear the conflict configuration to ensure that only one EID is registered by each IAD.
3. Check whether the fault is rectified.
   • If yes, the procedure ends.
   • If no, go to step 4

4. Ping the peer gateway from the IAD to check whether the network environment is good. (A good network environment indicates that the delay does not exceed 40 ms and no packet is lost.)
   • If no, optimize the network environment.
   • If yes, go to step 5.

5. Contact your service provider for assistance.