The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 18, 1990
Filed:
Mar. 31, 1988
Jayant G Hemmady, Naperville, IL (US);
William P Lidinsky, Naperville, IL (US);
Scott B Steele, Naperville, IL (US);
Werner Ulrich, Glen Ellyn, IL (US);
Roanld C Weddige, Western Springs, IL (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
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 tranmitted 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 desination user that is in the same group (virtual network) as the source user. This arrangement can also be used to switch voice packets, using a voice interface such as a digital switch and a digital voice signal to voice packet converter. In accordance with one embodiment of the invention, a packet switch is used for switching voice packet outputs of the data switching modules and a circuit switch, such as the space division switch, is used for switching data packet outputs.