A fault monitoring system having a reduced cost and management load. The system includes a voice/facsimile response unit composed of a controller and a network interface. The controller has a management server and a fault monitoring section to achieve the voice/facsimile response function. It dials through...http://www.google.com/patents/US6049592?utm_source=gb-gplus-sharePatent US6049592 - System for and method of mutually monitoring information guidance units interconnected to telephone lines
