Abstract: An instant telecommunications network backup system includes several trunk diverter circuits and several responder circuits. Each trunk diverter circuit is installed proximate to an originating central office within the telecommunications network and monitors an outgoing trunk for faulty conditions. The trunk diverter circuit maintains a database that classifies each responder circuits as being in one of two classes: a maintain link class and a disabled class. One or more responder circuits are installed proximate to an emergency response facility. Whenever a faulty condition is detected, the trunk diverter circuit establishes an alternative telecommunications path through either a public switch telephone network or a mobile telephone switching network to one of the responder circuits in the maintain link class. The trunk diverter circuit and the responder circuit exchange communications with each other.

Abstract: In order to provide call data monitoring for an Automatic Electric step-by-step switching system, the identification of the line number of a calling subscriber line in a group of subscriber lines is accomplished by identifying which of the line finders for that group has been selected by detecting a marked location in the selected line finder corresponding to the calling subscriber line and by detecting which of the common control relays for the group has selected and controlled the line finder. Identification of the line finder, the marked location and the common control relays are converted into the line number of the calling subscriber and stored as a first item in a call data record. The dialed telephone number of the called subscriber is determined and is stored as a second item in the call data record. The start time of the call is determined and is stored as a third item in the call data record. The duration of the call is determined and is stored as a fourth item in the call data record.