3com Corporation

Utstarcom, Incorporated

Thomas J Kostas

Ikhlaq S Sidhu

Guido M Schuster

Michael S Borella

David A Grabelsky

Jerry J Mahler

Jacek A Grabiec

A telephony system and method having a switch for analog voice and data signals that is connected to a first network, and a router for routing Internet Protocol packets that is connected to a second network using Internet Protocol addressing. The telephony system and method also includes a telephony gateway that is connected to both the switch and the router for converting analog voice signals into Internet Protocol packets and for converting Internet Protocol packets into analog voice signals, the telephony gateway being connected, and a remote access server that is connected to both the switch and the router for converting analog data signals into Internet Protocol packets and for converting Internet Protocol packets into analog data signals. The switch may have a switch matrix capable of being connected to the Public Switched Telephone Network, a line rack with a plurality of line cards connected to the switch matrix, and a trunk rack with a plurality of trunk cards connected to the switch matrix. The switch matrix may also be connected to the telephony gateway and the remote access server.

Architecture for a central office using IP technology

A mechanism for recovering data associated with lost packets, suitable for use in a VoIP network. The telecommunications network is preferably a packet switched network having IP telephony gateways serving as interfaces between a telephone device and the IP network. The IP telephony gateway receives a conversation signal from the telephone device, and implements an improved forward error correction method. The method includes generating payload information defined by at least two packet sequences from the same audio information, and transmitting those two packet sequences on the IP network for receipt by a remote network device. The packet sequences are transmitted using RTP with two independent data streams or, alternatively, using a single data stream. The first and second data streams are data packet streams each defining a sequence of data packets. The first data stream is preferably formed using a G.711 vocoder, and the second data stream is preferably formed using a G.723.1 vocoder. The receiver inserts the G.711 packets into a receive buffer, and, in the event that G.711 data is missing or corrupted, the receiver will decode the relevant G.723.1 packets and place it in the buffer in the appropriate location. The buffered data is then used to reproduce the audio information at the receiver.

Method and system for forward error correction with different frame sizes

A system for increasing call capacity of an internet telephony system in an emergency mode, such as where there is a surge of call requests in a particular region. A management system in the internet telephony system may detect the presence of an actual or potential state of congestion of call traffic and/or signaling traffic. In order to admit a higher rate of call traffic to the telephony system, action is taken to reduce the workload of the signaling system, in order to allow the telephony system to focus more on serving call requests. For example, the signaling system may reduce the rate of signaling request messages processed with respect to requested and ongoing calls and/or reduce the amount of processing involved in handling such messages.

Method and system for facilitating increased call traffic by reducing signaling load in an emergency mode

A method and apparatus for increasing call capacity in a packet switched telephony system in an emergency mode. The telephony system includes a management system, which detects an emergency, such as a surge in incoming media streams, a surge in traffic elsewhere in the system, a potential surge in traffic, and/or a convention emergency situation such as a natural disaster that may cause a surge in traffic. The management system alerts an internet telephony machine, such as a gateway, to the congestion problem. The internet telephony machine responds by switching to a lower bandwidth coder, thereby outputting each incoming media stream at a lower output rate, and thereby effectively increasing the capacity of the receive and handle calls.

Method and system for facilitating increased call traffic by switching to a low bandwidth encoder in a public emergency mode

A method and apparatus for controlling the transmission of real-time media signals over a data network based on a triggering event associated with a participating teleconference station. This triggering event may be the presence or absence of motion, the presence or absence of sound, or any of a variety of other events that preferably indicate the presence or absence of a person at the station. When no person is present at the station and/or when an appropriate triggering event occurs, remote teleconference participants will not transmit media signals over the network to the station, thereby conserving valuable network bandwidth and simulating a physically common meeting between people. In turn, when a person is present at the station and/or when another appropriate triggering event occurs, remote teleconference participants may start transmitting media signals over the network to the station. Additionally, a station may control its own transmission of media signals to remote stations in response to local triggering events, thus further conserving network resources.

Method and apparatus for controlling transmission of media signals over a data network in response to triggering events at participating stations

A system and method for receiving a transported stream of data packets includes a buffer management device for receiving the data packets, unpacking the data packets, and forwarding a stream of data frames. The system and method further includes a first jitter buffer for receiving the data frames from the buffer management device and buffering the data frames, and a second jitter buffer for receiving the data frames from the buffer management device and buffering the data frames. In addition, the system and method includes a computationally-desirable jitter buffer selected from the first jitter buffer or the second jitter buffer by comparing a first jitter buffer quality and a second jitter buffer quality. The system and method also includes a decoder for receiving buffered data frames from the computationally-desirable jitter buffer.

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Evanston, IL, United States of America

Thomas J Kostas