Northern Telecom Limited

Bellsouth Corporation

Sonu Mirchandani

Dale W Malik

Edgar Martinez

Adrian Giuhat

Mahmoud N Bargout

Portability of directory numbers in telephone networks, particularly so-called intelligent networks, may be provided without modification of the call processing software at originating network node switches, by associating each call to a ported number with an Initial Address Message comprising a Location Routing Number for the recipient switch as the Called Number and the ported directory number as the Original Called Number. At a boundary with a network which uses a Location Routing Number, a Generic Address Parameter and a Forward Call Indicator flag for identifying calls to ported numbers, a network element creates a modified routing message by converting the Original Called Number to a Generic Address Parameter and setting a Forwarded Call Indicator flag to indicate a translated originally-dialled called number. The network element then uses the converted Initial Address Message to route the call into the second network. Public Office Dialling Plan or Termination Attempt triggers may be used to interrupt processing of a call to the ported number and initiate a query to a Service Control Point database for the corresponding Location Routing Number for inclusion in the Initial Address Message. Alternatively, call forwarding at the donor switch may be used to provide the Location routing Number for the originating switch to include in the Initial Address Message.

Directory number portability in telephone networks

A method for a subscriber having a personal number to forward calls to a selected calling line. A communication directed to a predetermined number is received, and the calling line identification number (CLID) from which the call originated is obtained, as well as any extra digits entered by the subscriber. (80) The CLID is matched in a table to determine the subscriber associated with the CLID. (81) If no matches are found, the call is disconnected. (83) If more than one match is found, additional information is obtained to identify the desired subscriber. (85) Once the subscriber has been identified, a pointer is updated. (84) The pointer specifies the location (CLID) to which the calls are to be routed. Calls for that subscriber at his or her personal number are then forwarded to the calling line having that CLID.

Growing community of inventors

Norcross, GA, United States of America

Sonu Mirchandani