Origin of the call.

tapiOriginConference	Call in conference mode (several people).
tapiOriginInbound	Incoming call: communication coming from the outside. The use of this variable depends on the type of device used, on the driver, ...
tapiOriginExternal	Call coming from the outside. The use of this variable depends on the type of device used, on the driver, ...
tapiOriginUnknown	The origin of the call is not defined. The use of this variable depends on the type of device used, on the driver, ...
tapiOriginUnavailable	The origin of the call is not defined. The use of this variable depends on the type of device used, on the driver, ...
tapiOriginInternal	Call internal to PABX
tapiOriginOutbound	Outgoing call: communication toward the outside.

Identifier of the call to handle. This identifier is defined in the WLanguage procedure called by tapiListen.