Ring network security system with encoding of data entering a subnetwork and decoding of data leaving a subnetwork

Patent 5495580 Issued on February 27, 1996. Estimated Expiration Date:

February 27, 2013. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

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Inventor

Osman, Fazil

Assignee

XLNT Designs, Inc.

Application

No. 963726 filed on 10/20/1992

US Classes:

709/246COMPUTER-TO-COMPUTER DATA MODIFYING

Examiners

Primary: Lee, Thomas C.
Assistant: Dinh, D.

Attorney, Agent or Firm

Fish & richardson

International Classes

H04J 003/02
H04L 012/42
H04L 012/46

Abstract

A system for securing communications between devices connected to a ring network. In accordance with the present invention, when a message frame is passed around the ring network, a gate keeper circuit associated with at least one port of a hub determines whether the message frame is intended for any of the nodes connected to that port. If the message frame is not intended for any of the nodes connected to that port, the message frame is encoded before it exits the hub through the port to traverse the subnetwork connected to the port, and decoded after it reenters the hub through the port. If and only if at least one node on the subnetwork connected to the port is intended to receive the message frame, then each node connected to that port can read the message frame.