Abstract: A system is disclosed for selecting and establishing connections through a two-stage concentrator network utilizing path selection circuitry adapted to minimize blocking. This circuitry operates to select a path through the second-stage switch which is the least congested (i.e., has the most idle output lines). More specifically, "congestion" information is generated from "outlet" information specifying the idle/busy status of the outlets or terminals of the second-stage switches. This congestion information is logically combined with link information, specifying the idle/busy status of link paths interconnecting the stages, to ascertain if a path is available through one of the least congested second-stage switches. If a path is available, an idle outlet is selected on a least-congested second-stage switch, and then a connection is completed to the selected idle outlet.
Type:
Grant
Filed:
October 4, 1974
Date of Patent:
January 27, 1976
Assignee:
Bell Telephone Laboratories, Incorporated