Find which IMSI is making more this attempts

Hello,

I have a 2G cell that has from time to time almost 7000 call attempts, leading to a severe SDCCH congestion.
I want to know which IMSI is making all this attempts.

As I recall we were using some Astellia Module to figure this out and isolate that faulty UE/IMEI causing repeated location updates and failing.
But long time ago.

I checked, since the user still did not establish any connection with the MSC, we cant get any traces on Astellia tool.

In Huawei, you can get the cell trace data, import to FMA tool, it can help you to find top IMSI making calls.
In 2G, BSC receive IMSI number from MSC so BSC know exact number of calls.