Issue Description
There are 87XXXX long number for hunt group with 1xxx&11xx;the issue is when 055xxxxxx call for 87XXXX; the reject by 1xxx&11xx,after that from 1xxx&11xxthe call is end but mobile 055xxxxxxstill has the Calling
Network Topology: IPT . All phones are registered in the central U1981 and call out through PRA;
Handling Process
Analysis of the call logs of the subscriber (the busy tone is not heard)：
As shown in the following figure, The U19 receives a 486 (Busy Here) message after receiving a rejection message from a hunt group member，in the same time U19 sent the ALERTING message to the calling carrier：
In the message of the call log, you can see the following: U19 Sends a 140 message (User busy)：
Call log analysis in the simulated user scenario in the lab (the busy tone is played normally)：
The following figure shows the simulated call flow in the lab. The flow is the same as that obtained from the subscriber in the previous step. In addition, the tone indication carried in the Alerting message is the same：
Therefore, the processing mode of the U19 in this scenario is normal. However, the busy tone can be heard in the lab, but cannot be heard on the user site.
Root Cause
After rejecting the call, U1981 sends an ALERTING message to the Carrier, indicating that the called user is busy.
the Carrier did not understand or misunderstood the meaning of the ALERTING message send by U1981. So Carrier device play the call-waiting tone.
Solution
Carriers play announcements based on Huawei's requirements.
Change the icon whether to send exception tone to NO as below, because when the parameter is set to NO the system plays a tone when hang up.
