Patent Number: 6,298,057

Title: System and method for reliability transporting aural information across a network

Abstract: A system and method for transparently transmitting aural signals across a wide area network (WAN). The system of present invention is connected to one or more of a private branch exchange, a key telephone system, a telephone, a facsimile machine, and a modem, for example. In the case of voice transmission, a user places a telephone call using the same procedure that is used when placing a telephone call over a conventional public switched network. The aural signals are translated into a format that is compatible with the local area network (LAN) and the translated signals are transmitted to a router or a switch that connects the LAN to the WAN. The data is transmitted across the WAN to a router or switch coupled to a second LAN. The data is then sent to a destination central site unit or PC which translates the signal into a format that is compatible with the telephone system connected thereto. The present invention provides a voice quality that approaches, equals, or exceeds the voice quality of conventional telephone switched networks. This high voice quality is achieved by utilizing a high quality voice digitization algorithm, by ensuring a low maximum network delay, by dynamically compensating for variations in network delay, and by using a forward error correction technique that can recreate lost or delayed signals in a manner that recreates the signal so the lost signal is typically not detectable by a user.

Inventors: Guy; Kenneth R. (Thousand Oaks, CA), Jain; Jaswant R. (Chatsworth, CA), Jasuja; Ishwar V. (Simi Valley, CA), Johnson; Michael W. (Petaluma, CA), Juandy; Albert (Petaluma, CA), Lam; Simon S. (Agoura Hills, CA), Lee; Anthony Y. (Northridge, CA), Misunas; David (Thousand Oaks, CA), Roth; Jacques A. (San Rafael, CA)

Assignee: Nortel Networks Limited

International Classification: H04L 12/28 (20060101); H04J 3/06 (20060101); H04M 7/00 (20060101); H04L 1/00 (20060101); H04L 012/28 (); H04J 003/16 (); G06F 011/00 ()

Expiration Date: 10/02/2018