IVR Call Flow Diagram - Call Flow Execution

When an incoming call is answered by Voicent Gateway, it selects a deployed IVR application to handle the interactions with the caller. The following steps are executed for an IVR application:

Select active element. Initially, the top/root element is selected as the active element
Execute all actions of the active element
Play all prompt items of the active element
Execute the element
Based on caller input and defined transitions, select the next active element, go to step 2

Example

The call flow diagram is from the auto-attendant sample.

When an incoming call is answered, the IVR system is executed as follows:

Select Main Menu as the active element
This element has no action defined
Play the prompt of Main Menu. The prompt item is a text-to-speech item that asking the caller to "press 1 for sales, press 2 for service...". The system automatically uses the available Text-to-Speech engine to convert the text to voice.
The Main Menu element is a Choice element. It wait for caller input
If caller enters 2, the system checks all the transitions from Main Menu. If the condition of a transition is satisfied, the active element is set to the element the transition leads to. In this case, the Service element is set to be the active element. Then go to step 2.
The Service element has no action
The Service element has no prompt
The Service element is a Call Transfer element, it transfer the current call to the defined extension
There is no more transition from the Service element. The IVR application exits