keith has posted comments on this change. ( https://gerrit.osmocom.org/c/osmo-msc/+/28509 )

Change subject: Change CC_CAUSE returned on unanswered MT Call ......................................................................

Patch Set 1:

(1 comment)

File src/libmsc/gsm_04_08_cc.c:

https://gerrit.osmocom.org/c/osmo-msc/+/28509/comment/cf08d5bd_b34a264a PS1, Line 281: (trans->cc.state == GSM_CSTATE_CALL_RECEIVED) ? In adding this check, I should point out that I do not know what other CC state is possible when we reach this code, but in order to at least try not use the wrong cause for other situations, I decided to limit it to GSM_CSTATE_CALL_RECEIVED.

It might be better to know here if it was actually timer mgw X2 that expired. Maybe there is a way to know that, I don't see it glancing at what seems to be immediately available in trans or the msc_a. The timer expiration is quite some ways up the stack through various FSM callbacks. Or maybe there is another state we can check, for example, I thought to check for COMPLETE_LAYER3_PAGING_RESP. Even so, with those conditions in place, I don't think there is any way to know if the call was simply unanswered or if the MGW suffered some other problem?