CALL RECEIVING METHOD IN KEY TELEPHONE SYSTEM

PROBLEM TO BE SOLVED: To provide a receiving method, in a key telephone system whose call processing efficiency is made satisfactory by selecting only a terminal which accepts call setting at first in response to a line wire broadcast call as a receiving terminal, and immediately releasing the other terminals from the receiving state. SOLUTION: In this receiving method, in a key telephone system equipped with a main device connected to an ISDN line wire, and housed with plural ISDN terminals or terminals having layer 3 interfaces in the same way as the ISDN terminals in its extensions, the main device transmits a call setting message to all receivable terminals at receiving a line wire broadcast incoming call from the line wire, and selects the terminal which returns a call setting acceptance signal or a calling signal at first as an incoming terminal so that incoming processing can be performed, and immediately releases the other terminals.