Abstract: In an environment of competitive local and interexchange carriers, offering number portability between local carriers serving a common region and between switches serving that region, each local carrier accesses a regional database to determine the identity of the carrier and switch serving a local customer. In addition, interexchange carriers access a national database to determine the identity of the carrier and switch serving the customer specified by the number dialed by an originating customer. For customers requiring high reliability service, alternate carriers can be used to serve such customers in case the primary carrier is unavailable; the databases identify these alternate carriers. Advantageously, this arrangement allows a high degree of freedom of movement of customers between carriers and geographic relocation without requiring a number change.

Abstract: In accordance with the teachings of a prior application, in a telecommunications network, a local database stores destination telephone number information derived from a more global database, shared by a plurality of switching systems usually remote from all or most of the systems. One or more bit maps are used to store key indicators for each telephone number for which information may be required. This invention relates to a method and apparatus for automatically updating the local database, by recognizing that a switch identified as serving a directory number does not have access to the line corresponding to that number; when this condition is discovered, the global database is increased and the local database updated.

Abstract: In a telecommunications network, a method and apparatus for decreasing access time of information normally stored in a data base, shared by a plurality of switching systems usually remote from all or most of the systems. One or more bit maps are used to store key indicators for each telephone number for which information may be required. In one specific embodiment, a bit map indicates whether the information is stored locally in the switch, so that an access to the remote database is not required. In another embodiment, a bit map stores an indication of whether the desired information is a default attribute, or one of a plurality of common attributes of the information being sought. Advantageously, the number of data accesses required of the remote data base is sharply reduced, thus reducing the average call set up time.

Abstract: In an environment of competitive local and interexchange carriers, offering number portability between local carriers-serving a common region and between switches serving that region, each local carrier accesses a regional database to determine the identify of the carrier and switch serving a local customer. In addition, interexchange carriers access a national database to determine the identity of the carrier and switch serving the customer specified by the number dialed by an originating customer. For customers requiring high reliability service, alternate carriers can be used to serve such customers in case the primary carrier is unavailable; the databases identify these alternate carriers. Advantageously, this arrangement allows a high degree of freedom of movement of customers between carriers and geographic relocation without requiring a number change.