When the SoftCo connects to the IMS, inter-office calls may fail to be set up sometimes.
When a SoftCo user calls an inter-office user, the SoftCo user can hear the Ringback Tone (RBT) but the call is not set up. The IMS sends error message 422 to the SoftCo.
Step 1 Run the config modify sip parameter sessioninterval 1800 command to change the SoftCo heartbeat interval to 1800.
Step 2 If the fault persists, contact Huawei technical support engineers.
The SoftCo's heartbeat interval is different from that of the IMS.