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:
Jul. 07, 1987
Filed:
Sep. 26, 1984
Chin-Tau A Lea, Lisle, IL (US);
American Telephone and Telegraph Company, AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
A self-routing switching network interconnecting a plurality of interface controllers for communicating packets and circuit switched information via multiple paths with provision for diagnostic testing by allowing only single paths between any given set of input and output ports. The network comprises stages of switching nodes that are grouped in pairs. The stages are interconnected by links and each pair of switching nodes shares the same set of input links from the preceding stage. In normal operation, a pair of nodes determines one of a multiple of paths through the switching network by one of the pair responding to address information communicated via a link from an interface controller. After establishing a path through a particular node, that node transmits the address information to the next sequential stage. In order to perform maintenance operations, all pairs of nodes within a given stage are controlled by a single input signal which, when present, cause the nodes to cease to operate in pairs and to commence singular operation. This results in only one path existing through the stage for a given set of input ports and output ports.