Patent ID: 7606351
Filing Date: 2009-10-20
Classification: H04L,H04M,H04Q

Abstract:
1. A telephone number change notification method in a communication system comprising a first telephone, a second telephone, and a telephone exchange, the telephone exchange carrying out connection between the first telephone and the second telephone based on a telephone number called by the first telephone, the method comprising the steps of: determining, by the telephone exchange, whether the telephone number called by the first telephone has been changed; sending, by the telephone exchange, a prompt message asking for a telephone number notification request with a digital signature to the first telephone if the telephone number has been changed; forwarding, by the telephone exchange, a telephone number notification request with the digital signature sent from the first telephone in response to the prompt message to the second telephone having changed a telephone number; determining, by the second telephone, whether the digital signature in the forwarded telephone number notification request with the digital signature is valid or not; and notifying, by the second telephone, the first telephone of the new changed telephone number if the digital signature is valid.