Sbc Technology Resources, Inc.

At&t Labs, Inc.

Haifeng Bi

Samuel Sigarto

George C Allen, Jr

Richard Wayne Stephenson

Steven R Partridge

Tina M Sigarto

Matthew Wayne Stafford

Yetik Serbest

Weijing Chen

Bruce Allen Nance

Barbara Smith

Randy Beamon

Janice Elaine Doerner

Mehran Esfandiari

Gary Jonathan Gibbons

Paul August Kaschube

John Pinch

George Anthony Young

Reducing connection overhead in a communications network includes reusing at least one cached communication channel connecting a source and a destination. The at least one cached communication channel is cached for a variable duration.

System and method for measurement-based adaptive caching of virtual connections

Narrowband signaling from a transfer node for a call originating at an end office is received at a centralized control and signaling interworking function device in an asynchronous transfer mode switching network. The received narrowband signaling is converted to broadband signaling. The broadband signaling is provided to a plurality of trunk interworking function devices via the asynchronous transfer mode switching network, to establish a connection across the asynchronous transfer mode switching network, when the centralized control and signaling interworking function device and the plurality of trunk interworking function devices are determined to be members of a closed user group.

Secure ATM-based distributed virtual tandem switching system and method

Virtual circuits are dynamically established in a telecommunications network. A cache duration is adaptively determined based on at least one characteristic of the telecommunications network. A virtual circuit is established for a connection between a source and a destination. The virtual circuit is cached when the connection between the source and the destination terminates. The cached virtual circuit is reused when a new connection request occurs during the cache duration. The cached virtual circuit is released after the cache duration when no new connection request occurs during the cache duration.

A distributed network switching system includes a data network. The system also includes multiple access interworking function (A-IWF) devices each operating as a gateway that enables customer premises devices to directly interface into the data network. The system further includes a centralized control and signaling interworking function (CS-IWF) device that performs call control functions and administrative functions and is adapted to interface narrowband and broadband signaling for call processing and control within the data network.

ATM-based distributed network switching system

An adaptive SVC caching method and system are provided to offload the high processing capacity burden of ATM switches. After an SVC is established in a usual way for a call, it is not torn down after the conversation ends. Instead, the SVC is kept alive for a variable duration (i.e., delayed release) with the expectation that there will be another call request for the same terminating end office during that time. The caching duration is adaptively changed with call arrival rate and call setup delay in the ATM network in order to stay within a delay budget specified by the requirements.

A system and method for reducing and surviving failures in a voice trunking over ATM (VTOA) environment includes an ATM network having a plurality of interconnected ATM switches. The VTOA system also includes a CS-IWF complex having a plurality of interconnected CS-IWF units, each unit having a plurality of processors. An end office building may also be provided for interaction with the VTOA system. The end office building includes multiple T-IWFs, and a switch that distributes calls among the T-IWFs in a load sharing manner. Each T-IWF has a plurality of processors and is part of the VTOA system. A switch management system is also provided in the VTOA system. In order to reduce and survive failures, the switch management system includes a plurality of switch management system units. At least one of the switch management system units is a backup unit for at least one primary switch management system unit. Each switch management system unit provides application redundancy within itself.

Fault tolerant virtual tandem switch

A method for providing secure communications through a communications network comprising ATM channels and TDM channels. The communications network includes at least one closed user group of network elements configured to communicate with only other network elements in the closed user group. The method receives a connection setup request at an ingress ATM switch, via a UNI attached to the ATM switch, in response to a call initiated through a TDM channel. The UNI interfaces a first network element of the closed user group with the ATM switch. The method further verifies that an ATM End System Address (AESA) contained in calling party information of the connection setup request is consistent with the attached UNI. Additionally, the method establishes a connection with at least a second network element of the closed user group through an egress ATM switch in the communications network when the AESA is consistent with the attached UNI.

An Asynchronous Transfer Mode (ATM)-based distributed virtual tandem switching system is provided in which a network of ATM-based devices is combined to create a distributed virtual tandem switch. The system includes an ATM switching network that dynamically sets up individual switched virtual connections. The system also includes a trunk interworking function (T-IWF) device and a centralized control and signaling interworking function (CS-IWF) device. The trunk interworking function device converts end office voice trunks from TDM channels to ATM cells by employing a structured circuit emulation service. The centralized control and signaling interworking function device performs call control functions and interfaces narrowband signaling and broadband signaling for call processing and control within the ATM switching network. Consequently, the ATM based distributed virtual tandem switching system replaces a standard tandem switch in the PSTN.

Virtual tandem switch

Distributed virtual tandem switch

An Asynchronous Transfer Mode (ATM)-based distributed network switching system includes an ATM switching network that dynamically sets up individual switched virtual connections. The system also includes multiple access interworking function (A-IWF) devices each operating as a gateway that enables customer premises devices to directly interface into the distributed ATM switching fabric. The system further includes a centralized control and signaling interworking function (CS-IWF) device that performs call control functions and administrative functions and is adapted to interface narrowband and broadband signaling for call processing and control within the ATM switching network. The CS-IWF device may be a server farm.

A system and method for ensuring security in a voice trunking over ATM (VTOA) environment is provided. A telecommunications network is provided that carries control traffic and bearer traffic via ATM communications channels and TDM communications channels. The telecommunications network includes at least one closed user group consisting of multiple closed user group members. The closed user group members include trunk interworking function (T-IWF) devices configured to receive end office voice trunks from TDM channels and convert the trunks to ATM cell streams and to receive ATM cell streams and convert the ATM cell streams to end office voice trunks; and at least one centralized control and signaling interworking function (CS-IWF) device. The CS-IWF device performs call control functions and interfaces narrowband and broadband signaling for call processing and control within the ATM switching network. The closed user group members also includes a VTOA switch management system (SMS). Other elements of the network include ATM switches forming the ATM network and an ATM element management system that manages the ATM switching network. The network also includes end office switches that communicate with the trunk interworking function (T-IWF) devices and the at least one centralized control and signaling interworking function (CS-IWF) device via TDM communications channels. The closed user group members are restricted to communicating solely with other closed user group members when communicating to each other via the ATM switching network.

ATM-based distributed virtual tandem switching system

System and method of measurement-based adaptive caching of virtual connections

An Asynchronous Transfer Mode (ATM)-based distributed virtual tandem switching system is provided in which a network of ATM-based devices is combined to create a distributed virtual tandem switch. The system includes an ATM switching network that dynamically sets up individual switched virtual connections. The system also includes a trunk interworking function (T-IWF) device and a centralized control and signaling interworking finction (CS-IWF) device. The trunk interworking function device converts end office voice trunks from TDM channels to ATM cells by employing a structured circuit emulation service. The centralized control and signaling interworking function device performs call control functions and interfaces narrowband signaling and broadband signaling for call processing and control within the ATM switching network. Consequently, the ATM based distributed virtual tandem switching system replaces a standard tandem switch in the PSTN.

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Austin, TX, United States of America

Haifeng Bi