Method of making call-wait and call-alternation in electronic private branch exchange (EPBX)

摘要

There is disclosed a method of making a call in an electronic private branch exchange system (EPBX), calling a subscriber pre-engaged in a call and thereby performing call-wait and call-alternation. The improvement performs a call-wait state so that a calling subscriber of an EPBX can be automatically linked up with a target subscriber of the EPBX, later on, if the target subscriber is already engaed in other call when the calling subscriber makes a call to the target subscriber. The invention also provides a subscriber of an EPBX with a method capable of switching a call central office from a line to another subscriber of the EPBX engaged in the other call.