>Mostly this is related to poor Radio coverage, then wrong cause code Mapping.This can be due to sending wrong cause code by BSC or MSS.
>IF your call uses TMSS with alternative path it is common to see such behavior. for example your node is connected to two TMSS A and TMSS B – Mapping in TMSSA is wrong but in TMSS B is correct,considering Subscriber is out of reach or cant response to Paging whenever your call established from TMSS A your hear CALLED IS POWER OFF and when via TMMS B you hear Real announcment, and when it is established normally it is ok 🙂
Mapping is a big issue especially between two oprators , currently we have found out this problem too in our Network
Hope it comes in use 🙂