Private branch exchange, private branch exchange control method, and private branch exchange control program

摘要

PROBLEM TO BE SOLVED: To provide a private branch exchange or a private branch exchange capable of correctly recognizing that an incoming call is abandoned on the way and correctly restricting an external line transmission from an extension terminal to which an external line transmission restriction is applied. To provide a control method and a control program for a private branch exchange. SOLUTION: The premises exchange 11 according to the present disclosure connects an external line connection unit 113 for interface with an external line, an extension connection unit 112 for interface with a connection with an extension terminal 12, and an external line and an extension terminal 12. The control unit 111 includes a control unit 111 to control, and the control unit 111 receives an incoming call from an external line while the external line connecting unit 113 receives an incoming call from an external line and the extension connecting unit 112 calls an incoming call to the extension terminal 12. If the extension terminal 112 is abandoned and the extension connection unit 112 detects an incoming response to an incoming call from the extension terminal 12, and the extension terminal 12 is a terminal whose transmission to the outside line is restricted, the extension terminal 12 is changed to the outside line. Do not connect. [Selection diagram] Fig. 1