originating call gsm

RR conection establishment GSM/RRC connection procedure
BSSMAP call setup to MSC /MS service request/accept
Authebtication
Ciphering
CC setup
CC call proceeding
BSSMAP assignment requets from MSC to SS for voice /RANAP RAB setup
RR channel modify from BSC to BTS
IAM
ACM
CC alerting
ANM
http://www.eventhelix.com/RealtimeMantra/Telecom/GSM_Originating_Call_Flow.pdf