In Intelligent Network and CAMEL switching, a BCSM is a Basic Call State Model .[ 1]
O-BCSM (Originating BCSM)
T-BCSM (Terminating BCSM)
A fundamental concept for IN control is the basic call state model (BCSM). When a call is processed
by an exchange, the call goes through a number of pre-defined phases. These phases of the call are
described in the BCSM. The BCSM generally follows the ISUP signalling of a call
State machine description [ edit ]
In the following IN BCSMs, bold Detection Points and Points In Call are also present in the CAMEL Ph1 subset.
TODO: Expand to Ph2,3,4
1. O_Null & Authorize Origination Attempt
2. Collected_info (Merged with 1. in CAMEL Ph1)
3. Analyze_Info
4. Routing & Alerting (Merged with 3. in CAMEL Ph1)
5. O_Active
6. O_Exception
1 Origination_Attempt_Authorized
2 Collected_Info
3 Analyzed_Info (this is the only Statically armed DP, others are dynamically armed using "Request Report BCSM (RRBE)" message by the SCP)
4 Route_Select_Failure
5 O_Called_Party_Busy
6 O_No_Answer
7 O_Answer
8 O_Mid_Call
9 O_Disconnect
10 O_Abandon
7. T_Null & Authorize Termination_Attempt
8. Select_Facility & Present_Call
9. T_Alerting (Merged with 8. in CAMEL Ph1)
10. T_Active
11. T_Exception
12 Termination_Attempt_Authorized
13 T_Called_Party_Busy
14 T_No_Answer
15 T_Answer
16 T_Mid_Call
17 T_Disconnect
18 T_Abandon
basic INAP call example