Change CC_CAUSE returned on unanswered MT Call
The timer "mgw X2" (RTP stream establishing timeout)
is set by default to 30 seconds.
When an MT call is ringing and remains unanswered, it
is this timer that will expire, and the call is terminated.
Up to now this results in a CC_CAUSE of Resource Unavailable
and if osmo-sip-connector is in use, the SIP agent will
get 503 Service Unavailable.
While "resource unavailable" may be technically correct, in
that the MGW did not return an rtp stream in time, returning
"No User Responding" (resulting in SIP 480) is probably a
more accurate description of what actually happened,
allowing the switch to inform the caller.
Change-Id: I4a9cfc388ec9ecb743d154a114a6db638eac4701
diff --git a/src/libmsc/gsm_04_08_cc.c b/src/libmsc/gsm_04_08_cc.c
index 8132de5..99174de 100644
--- a/src/libmsc/gsm_04_08_cc.c
+++ b/src/libmsc/gsm_04_08_cc.c
@@ -278,6 +278,8 @@
if (trans->cc.mncc_initiated) {
mncc_release_ind(trans->net, trans, trans->callref,
GSM48_CAUSE_LOC_PRN_S_LU,
+ (trans->cc.state == GSM_CSTATE_CALL_RECEIVED) ?
+ GSM48_CC_CAUSE_USER_NOTRESPOND :
GSM48_CC_CAUSE_RESOURCE_UNAVAIL);
}