Hi Pix,
There is no fail for Abis and A interface. Because BSC release SDCCH channel after 42 sec and it is pegged in SD_ABIS_FAIL_CALL.
I found that there is some USSD service which waits answer from UE on SDCCH.
I just tried to increase T9105, but there is no response from operator tı implement it
Fyi, MehmedO