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:
Aug. 12, 1997
Filed:
Jun. 01, 1995
John G Waclawsky, Frederick, MD (US);
Paul C Hershey, Manassas, VA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A system and method for passively measuring and correcting ring latency on a token or FDDI ring includes generating bits and token frames in a defined pattern according to the token ring protocol. A passive device coupled to the token ring measures CMIN, the minimum spacing, CMAX, the maximum spacing in bits and calculates Fi the frequency of changes in Cmin and Cmax between successive tokens or a token and a frame on the ring. A latency event vector Li is generated by the passive device. A controller responsive to the latency vector Li corrects the spacing between successive tokens or a token and frame to achieve a constant ring latency regardless of electrical or operational changes on the token ring.