Method and apparatus for screening calls in telephone networks

Abstract

A telephone network comprises at least one switching unit having a plurality of subscriber access lines each having an associated calling number and, a storage device storing a plurality of listings of destination numbers. Each listing is associated with a respective one of the calling numbers and defines defining a personalized local calling area for that particular calling number. The switching unit detects a destination number dialed by a caller setting up a call, accesses the personalized local calling area listing for that calling number, and compares the detected destination number with the selected listing to determine whether the call is local or long distance. Each of the listings may comprise numbers having between three and ten digits. Provision may be made for the subscriber to create the personalized calling area by adding entries to, or deleting entries from, a standard local calling area common to a group of subscribers. The storage device may comprise central storage storing a plurality of listings for each of a plurality of switches in the network, and local storage associated with each of the switches for storing the plurality of listings for that particular switch.