METHOD FOR CONTROLLING CALLS BY EXTENSION GRADE IN A KEYPHONE SYSTEM, SPECIALLY CORRELATED TO AUTOMATICALLY CONTROLLING SPEECH PATHS BY ASSIGNING GRADES TO EXTENSION CALLS

摘要

PURPOSE: A method for controlling calls by extension grade in a keyphone system is provided to give a priority to an extension group having a specific grade with a receiving call reject function, and to automatically control speech paths by differentiating the paths within the group, thereby realizing user convenience. CONSTITUTION: When an apparatus is in standby mode, a CPU checks a state of an extension subscriber circuit, senses inputted digits when a call request is received from one extension, and detects whether the sensed digits refer to an extension call(202-206). If so, the CPU forms a speech path after seizing a local line connected to a local line subscriber circuit(208). If a called originating extension and a called receiving extension have upper grades, the CPU reads a storage area of a memory to detect whether a priority grade of the called originating extension is smaller than that of the called receiving extension(210-214). If not, the CPU forms a speech path to connect a call(218-220).