3.2 Basic Call Model

Each call received or generated by Global Call is processed through a series of states, where each state represents the completion of certain tasks or the current status of the call. Some states in the basic call model are optional and can be enabled or disabled selectively. Only the optional states can be enabled or disabled. Every technology or call control library has a default call state model consisting of all the states it can possibly support from the basic call model. If a state is disabled, all corresponding events are disabled. If a state is enabled, all corresponding events are enabled.

The call states change in accordance with the sequence of functions called by the application and the events that originate in the network and system hardware. The current state of a call can be changed by:

• Function call returns
• Termination events (indications of function completion)
• Unsolicited events

The states of the basic call model are described in the following sections:

• Basic Call States at the Inbound Interface
• Basic Call States at the Outbound Interface
• Basic Call States for Call Termination

Click here to contact Telecom Support Resources