Incoming call control system of digital telephone exchange

Abstract

Abstract PURPOSE:To avoid the reduction of efficiency due to the overload of a CPU in an abnormal congestion mode of calls by decreasing the number of originating register trunks to control the incoming calls. CONSTITUTION:An overload monitor circuit OVLSUP monitors an overload state of a central processing unit CPU and then closes a part of an originating register trunk ORT via a channel system controller SPC when the 80% CPU efficiency is detected by a data bus monitor system or a program monitor system, etc. The CPU suffices just with the busy tone track BTT connection processing and the cut processing without performing the dial-tone connection processing, the numerical character analysis processing, the outgoing connection processing, etc. Thus a normal processing state is maintained even with an abnormal congestion of calls.

Inventors

• 👤 Tsuguo Hata
• 👤 畑　紹夫
• 👤 Hideki Yamamoto
• 👤 山本　英毅

Bibliographic Details