Calls Between IAD Users Are Disconnected Sometimes

Symptom

A SoftCo9500 and 23 IADs are connected to the external network through the PRA trunk. Calls between IAD users or Outer-Office users are sometimes disconnected. The line disconnected is random. When a call is disconnected, a registration failure occurs on the IAD, but is automatically rectified in 10 seconds.

Possible Cause

The possible cause is that the softswitch restricts the registration message traffic, resulting in registration of multiple times.

Solution

1. Capture and analyze IAD logs. If the softswitch does not respond to the registration message sent by the IAD, the IAD sends a BYE message to terminate the session and re-sends registration messages until the registration is successful.
2. Check whether the traffic is restricted on the softswitch.
   • If yes, run the fpga set limitflux enable protocol sipreg flux 50 command on the softswitch to disable the traffic restriction.
   • If no, go to step3

3. Configure a different registration duration on the IAD. For example, run the sip server 0 address 192.166.1.16 expire-time 200 command.
4. Check whether the fault is rectified.
   • If yes, the procedure ends.
   • If no, go to step 5.

5. Contact your service provider for assistance.