US Patent 7573828 Fault isolation system and method

A fault isolation system and method. A hierarchical numbering system is applied to devices within a cable network. Each subscriber is associated with a “last active device” or “LAD” providing service to that subscriber. The numbering system provides “genealogical” information about the subscriber's LAD so that the LAD can be located within the network. By correlating trouble reports from subscribers, a fault in an active device can be isolated to a particular segment of a cascade if not a particular active device. The number system comprises a continuously concatenated string that provides a relative location of each active device with a cable network.