Phones connected to the IAD can ring but nothing is heard after pickup

Hi, all!

Have a nice day to you!

This topic describes the solution to phones connected to the IAD can ring but nothing is heard after pickup.

Possible Cause

The signaling carries events that the IAD does not support.

Solution

1. Capture packets on the faulty IAD.

2. Analyze the packets captured on the faulty IAD. Check whether the IAD sends a 518 error code to the softswitch.
   

   NOTE:
   

   The IAD does not support softswitch messages that contain FXR/T38 events. Common MDCX messages do not contain FXR/T38 events.

   If yes, change the T38 mode to transparent transmission mode for the softswitch.

Thanks!