What is BCSM (Basic Call State Model)?

A major idea for Intelligent Network control is the basic call state model (BCSM). The call goes through a number of pre-defined phases,at the point when a call is processed by an exchange. The BCSM is a high-level finite state machine description of the Call Control Function (CCF) exercises needed to set up and keep up with communication paths for clients who have Intelligent Network services.