PURPOSE: To improve service for a caller using extension telephone set with respect to a trunk line incoming call control system receiving extension selection information to be transmitted after incoming call trunk line and calling the extension telephone set.
CONSTITUTION: A central control unit 101 receives the extension selection information from a central office trunk 110. When the extension telephone set 105 is busy, it controls a voice message transmitter 111 and sends busy information and selectable service information to the caller. Then, the central control unit 101 receives the service selection information from the caller, and performs the control for a variety of services based on the information. Thus, the service for the caller is improved since a variety of services can be selected by the caller when the extension telephone set is busy.
KUGE YUTAKA
SAITOU YUKIMUNE
IMAI JUNICHI
