US 5,625,681 A · Method and apparatus for telephone number portability

Abstract

A telephone network includes switches which are capable of mapping between subscriber numbers, which are owned by the subscriber, and provider numbers, which define the physical location of the switch at which the subscriber is connected, in order to provide portability of telephone numbers. Switches which are capable of porting telephone numbers may access a database to look-up a provider number based on a subscriber number and look-up a subscriber number based on a provider number. The subscriber number of the called party is translated to a provider number in order to define the physical location of the switch supporting the called party. The provider number of the calling party is translated to a subscriber number to support caller ID. The database for maintaining information on translating subscriber numbers and provider numbers, and other data, such as call forwarding and switch configurations, may be accessed from a central database and cached locally to the switches.

Claims9

Dependent claims

In a communication system comprising a plurality of interconnected switches, a method of forming a connection from a calling party to a called party, comprising the steps of:

dialing a subscriber number assigned to the called party;
if a switch receiving said subscriber number is of a first type, routing the call responsive to the subscriber number of the called party;
if a switch receiving said subscriber number is of a second type, determining a provider number of the called party based on said subscriber number, wherein the provider number of the called party identifies a particular switch associated with the called party, and routing the call responsive to the provider number of the called party;
identifying a provider number of said calling party, wherein said provider number of the calling party indicates the switch that initially received the subscriber number of the called party;
and
translating the provider number of the calling party to a subscriber number associated with the calling party upon receiving a provider number of the calling party in a switch of said second type.

3 more elements

Dependencies are inferred from the claim text.

Method and apparatus for telephone number portability

Life of this patent

Method and apparatus for telephone number portability

Life of this patent

Abstract

Claims9