Communication facilities access control arrangement

摘要

The communication facilities access control arrangement of the telephone communication system detects the dialing of an unauthorized or invalid long distance transmission facility access code and identifies the calling station. A record is maintained of all invalid attempts to access the long distance facilities. When the number of invalid attempts by a calling station exceeds a predetermined limit, the telephone communication system restricts the calling station from all further long distance transmission facility access and generates an alarm indication to identify a possible facility access problem.