IncomingCall indicates that a call has been received by the application server.

When a call is inbound to an script via IncomingCall, the call is in a ringing state and a script can choose to do one of 5 things: RejectCall, AnswerCall, Redirect, AcceptCall, or simply do nothing with the call.

The RemoteHangup event can occur after IncomingCall, even if the call has not been answered. In this case, just as when the call has been answered and is established, it indicates that the remote endpoint has terminated the call, and the call is over.

The Call Control API makes every effort to abstract the complexities of the underlying telephony protocol; however, one should consult the Call Control Feature Matrix to understand what Call Control actions and action parameters are valid for each of the four supported protocols. One can set installation and deployment guidelines based on the Call Control actions and action parameters that an application uses; the Call Control Feature Matrix makes developing such guidelines feasible.