Hitachi, Ltd.

Tomohiro Baba

Hirofumi Masukawa

Junnosuke Wakai

Taketoshi Kawashima

Kazumi Hakuta

Shiro Ohtani

Hisanori Kimoto

Kenichi Sakamoto

Shinichi Akahane

Daisuke Matsubara

Toshiaki Tarui

Yasushi Fukuda

Hiroki Yano

Hiroki Miyamoto

Satoshi Kiyoto

Nobuo Ogasawara

Isao Shimokawa

Systems, methods and devices for failure analysis are provided. Using aggregation flow mining (AFM) or a similar method, an integrated mining of flow (IMF) acquires, from each router to be tested, information relating to each flow. The IMF, in relation to each of the routers, obtains distributions of statistical information such as throughput or difference for each flow; calculates, in relation to each of the distributions, a Mahalanobis distance in relation to the expected value of a reference distribution; and makes a comprehensive assessment of the distributions to perform a fault determination. When the fault determination is performed, a normal value of the distribution used for comparison is acquired from AFM and updated through feedback as needed. After the results of fault determination relating to other routers are assessed, the expected value of the standard deviation and the average value of the reference distribution used for comparison are updated.

Failure analysis device, and system and method for same

Provided is a network system including a traffic information aggregating apparatus connected to a router for transferring data in a network, and a monitor server connected to the traffic information aggregating apparatus. In the network system, the traffic information aggregating apparatus receives traffic information from the router, assigns an aggregation identifier to the received traffic information, creates aggregated information by aggregating the traffic information based on the assigned aggregation identifier and by statistically processing the traffic information, transmits the created aggregated information and the assigned aggregation identifier to the monitor server, and retrieves, upon reception of a retrieval request including the aggregation identifier from the monitor server, requested traffic information from the received traffic information, based on the aggregation identifier included in the received retrieval request. Accordingly, an amount of data received by the monitor server can be reduced.

Traffic information aggregating apparatus

When any communication port receives a packet from a network, it transmits the packet to a relay processing section. The relay processing section identifies a relay processing section of a transfer destination according to destination information included in the packet to transmit the packet to a packet switch section. When the relay processing section of the transfer destination is a working relay processing section, the packet switch section transfers the packet to the working relay processing section and a protection relay processing section.

Packet routing apparatus and a method of communicating a packet

A packet routing apparatus has a routing information table comprised of a plurality of sub-tables. Each sub-table includes an entry of a first format indicative of routing information, and at least one of the sub-tables includes, in addition to the entry of the first format, an entry of a second format for designating another sub-table to be referred to. A routing processor of the packet routing apparatus refers to a sub-table designated by an input line interface. As a result, when the entry of the second format is retrieved, the routing processor executes routing of an input packet and header conversion by referring to another sub-table designated by the entry.

Packet routing apparatus and routing controller

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Tachikawa, Japan

Tomohiro Baba