Dear , All
I am responsible to monitor the KPI for each office. During the three last months we launched the CRBT service, and during the monitor processing I notice some value in Call drop rate (%).
We connect to CRBT service center By GMSC (Gateway) BSC…. VMSC,,,,,, GMSC,,, CRBT.
We found High call drop rate in GMSC office, but this value with no sense, because according to our customer this service are ok.
The reason was:
After normal signaling interact, if called number has CRBT service, VMSC send IAM(include called number xxxxxxxxxxxxxxxxx),SAM to CRBT by GMSC,and CRBT return ACM,ANM back to VMSC.
Now you can hear color ring. Before called party answer, you or called party release call , release cause value is “normal, unspecified” and GMSC think it as call drop rate.
Why call release cause ???
Could you help me to simplified this reason