Transfers an active call to another extension. This is a blind transfer, meaning the transferor does not talk to the transferee.
If a function is passed in the handler parameter, that function is called with a call status object to notify of state changes to the phone call.
Identifier of the call to act on. A call handle can be obtained by observing call events. Information such as this will be passed into the event object.
Number to dial.
Handler to register for the call. Executed whenever the call changes state.