Basic call state model


In Intelligent Network and CAMEL switching, a BCSM is a Basic Call State Model.

Types

  • O-BCSM
  • T-BCSM
A fundamental concept for IN control is the basic call state model. 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

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

O-BCSM

Points in call

  • 1. O_Null & Authorize Origination Attempt
  • 2. Collected_info
  • 3. Analyze_Info
  • 4. Routing & Alerting
  • 5. O_Active
  • 6. '''O_Exception'''

Detection Points

  • 1 Origination_Attempt_Authorized
  • 2 Collected_Info
  • 3 Analyzed_Info
  • 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

T-BCSM

Points in call

  • 7. T_Null & Authorize Termination_Attempt
  • 8. Select_Facility & Present_Call
  • 9. T_Alerting
  • 10. T_Active
  • 11. '''T_Exception'''

Detection Points

  • 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

Messages

[Image:Simple call example (INAP) for BCSM.jpg|right|thumb|basic INAP call example]