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:
Jun. 14, 2011
Filed:
Mar. 27, 2007
Masahiro Maruyoshi, Chiba-ken, JP;
Muneyoshi Suzuki, Chiba-ken, JP;
Kunio Hato, Chiba-ken, JP;
Katsuya Minami, Chiba-ken, JP;
Masahiro Maruyoshi, Chiba-ken, JP;
Muneyoshi Suzuki, Chiba-ken, JP;
Kunio Hato, Chiba-ken, JP;
Katsuya Minami, Chiba-ken, JP;
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Abstract
In a ring redundant communication path control method, each of transfer apparatuses periodically transmits an inspection frame for inspecting a communication path, detects a failure of the communication path when the inspection frame is not received for a fixed time, transmits a non-arrival notification frame for notifying that the inspection frame has not arrived yet, and detects a failure of the communication path when the non-arrival notification frame is received. Each of the transfer apparatuses closes, when a failure is detection, a port in which the failure is detected, transmits an open command frame for commanding to open a normally closed port from the other port other than the closed port, transfers an open command frame when the open command frame is received, and opens the normally closed port when the other port other than the closed port in which the failure is detected, the port in which the open command frame is detected, or the other port configuring a ring redundant communication path same as that of the port is the normally closed port.