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:
Jan. 18, 1994
Filed:
Jul. 27, 1990
Henry Yang, Andover, MA (US);
Kadangode K Ramakrishnan, Maynard, MA (US);
Paul W Ciarfella, Arlington, MA (US);
Digital Equipment Corporation, Maynard, MA (US);
Abstract
A ring purging station for a token-ring network is disclosed. The station performs purging operations to remove no-owner frames and frame remnants from the network. The station begins a purging operation by detecting the token on the network and removing it. The station then begins stripping all frame and remnants of frames that it receives from the network, transmits one or more purge marker frames, and sets a purge operation timer to expire after a predetermined period of time. The predetermined period of time is greater than the maximum time required for a frame to propagate around the token ring network when the ring is not malfunctioning. The predetermined period of time may also be less than a valid transmission time period. When the station either detects one of the one or more purge marker frames it transmitted, or when the purge operation timer expires, the station ends the purging operation, and releases the token back onto the ring. The station is also capable of selecting, in cooperation with the other stations, which station is to operate as purging station. The station is further capable of performing duplicate address tests, and will terminate any purging operation upon detection of a duplicate address. In this way no-owner frames and frame fragments are removed from the network, while the ring is otherwise normally operating.