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:
May. 01, 2012
Filed:
Feb. 08, 2007
Masayuki Takase, Kokubunji, JP;
Kenichi Sakamoto, Kokubunji, JP;
Masahiko Mizutani, Kokubunji, JP;
Hideki Endo, Hachioji, JP;
Yoshihiro Ashi, Yokohama, JP;
Takayuki Kanno, Yokohama, JP;
Nobuyuki Yamamoto, Yokohama, JP;
Masayuki Takase, Kokubunji, JP;
Kenichi Sakamoto, Kokubunji, JP;
Masahiko Mizutani, Kokubunji, JP;
Hideki Endo, Hachioji, JP;
Yoshihiro Ashi, Yokohama, JP;
Takayuki Kanno, Yokohama, JP;
Nobuyuki Yamamoto, Yokohama, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
The invention realizes defect indication on a multipoint logical path and switching of the logical path using a transfer protocol of configuring a logical path in a ring network. A working path and a backup path are set up where each transmits a frame from a transmitting end node to multicast receiving end nodes, forwards the frame to the transmitting end node and terminates it at the transmitting end node after going around the ring. Any node detecting a defect transmits a forward defect indication frame to a multipoint logical path in which the defect occurs. The transmitting end node receiving the forward defect indication frame halts the use of the notified multipoint logical path, and transmits a frame in another path where the forward defect indication frame is not received. When received from both multipoint logical paths, the transmitting end node copies the frame and forwards them to both paths.