American Telephone & Telegraph Co., At&t Bell Laboratories

Other

Michael J Knudsen

Gaylord W Richards

Jayant G Hemmady

Gary A Roediger

Robert K Nichols

William P Lidinsky

Scott B Steele

Bruce R Zelle

Ronald C Weddige

A shield attachable to a cooking stove to prevent small children from reaching surface burner units or hot cooking containers on the stove top surface. The shield includes an upstanding panel spaced forwardly from the stove and two horizontal plates extending from the lower edge of the panel into a door clearance space along the upper edge of an oven access opening. Screws can be extended through slots in these horizontal plates to rigidly mount the protective shield on the stove.

Protective shield for stove

A high capacity metropolitan area network (MAN) is described. Data traffic from users is connected to data concentrators at the edge of the network, and is transmitted over fiber optic data links to a hub where the data is switched. The hub includes a plurality of data switching modules, each having a control means, and each connected to a distributed control space division switch. Advantageously, the data switching modules, whose inputs are connected to the concentrators, perform all checking and routing functions, while the 1024.times.1024 maximum size space division switch, whose outputs are connected to the concentrators, provides a large fan-out distribution network for reaching many concentrators from each data switching module. Distributed control of the space division switch permits several million connection and disconnection actions to be performed each second, while the pipelined and parallel operation within the control means permits each of the 256 switching modules to process at least 50,000 transactions per second. The data switching modules chain groups of incoming packets destined for a common outlet of the space division switch so that only one connection in that switch is required for transmitting each group of chained packets from a data switching module to a concentrator. MAN provides security features including a port identification supplied by the data concentrators, and a check that each packet is from an authorized source user, transmitting on a port associated with that user, to an authorized destination user that is in the same group (virtual network) as the source user. Distributed control of the space division switch is implemented by dividing that switch into disjoint sets of connection and switching elements and controlling each such set with a different controller. These controllers communicate via a separate control network with the data switching modules which request circuit connections.

Control network for a rapid connection circuit switch

A high capacity metropolitan area network (MAN) is described. Data traffic from users is connected to data concentrators at the edge of the network, and is transmitted over fiber optic data links to a hub where the data is switched. The hub includes a plurality of data switching modules, each having a control means, and each connected to a distributed control space division switch. Advantageously, the data switching modules, whose inputs are connected to the concentrators, perform all checking and routing functions, while the 1024.times.1024 maximum size space division switch, whose outputs are connected to the concentrators, provides a large fan-out distribution network for reaching many concentrators from each data switching module. Distributed control of the space division switch permits several million connection and disconnection actions to be performed each second, while the pipelined and parallel operation within the control means permits each of the 256 switching modules to process at least 50,000 transactions per second. The data switching modules chain groups of incoming packets destined for a common outlet of the space division switch so that only one connection in that switch is required for transmitting each group of chained packets from a data switching module to a concentrator. MAN provides security features including a port identification supplied by the data concentrators, and a check that each packet is from an authorized source user, transmitting on a port associated with that user, to an authorized destination user that is in the same group (virtual network) as the source user. The data switching modules each use a synchronous data ring for transporting data packets between data link handlers and a plurality of memory access controllers and their associated memory modules.

Arrangement for switching concentrated telecommunications packet traffic

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Wheaton, IL, United States of America

Michael J Knudsen