Hitachi, Ltd.

Alaxala Networks Corporation

Other

Hitachi Engineering Co., Ltd.

Hitachi Microsoftware Systems, Inc.

Hitachi Asahi Electronics Co., Ltd.

Hitachi Information Technology Co., Ltd.

Kazuo Sugai

Shinichi Akahane

Nobuhito Matsuyama

Takeshi Aimoto

Takeki Yazaki

Yoshihito Sako

Hiroki Yano

Tomohiko Tanabe

Takao Nara

Yuichi Ishikawa

Takayuki Muranaka

Takeshi Kumagai

Teruo Kaganoi

Mitsuru Nagasaka

Tatsuo Kanetake

Yasuhiro Kodama

Takashi Kumagai

Naoya Kumita

Tomohiko Kohno

Kenichi Sakamoto

Takashi Matsumoto

Kazuaki Tsuchiya

Ken Watanabe

Toshio Doi

Masatoshi Hino

Kouji Fukuda

Yoshihiko Sakata

Masaaki Inoue

Junji Baba

Katsuyoshi Onishi

Hiroshi Sekino

Tomohiko Kouno

Takaharu Aoyama

Hirotoshi Kino

Koyuru Nagao

Manabu Sawa

Kazuhiro Matsuo

Kaoru Okano

Noboru Tanabe

Yukisada Yamakawa

Takeshi Gotou

Satoshi Hatanaka

Toshimi Sugita

Tsuyoshi Katoh

Hirokatsu Shioda

Takumi Nakaki

Kazutaka Itou

Hideo Haruta

Kazuko Ito

Hisaaki Shibata

Yasuaki Sato

Shuichi Hiruoka

Yoshinori Hachiya

A communication system, comprising: a communication apparatus controlling transmission and reception of data in a network connecting a server and a user terminal; and a management apparatus, the network including an edge apparatus, the communication apparatus including a relay unit which has a queue for each communication flow, and controls the transmission and reception of data using the queue, the management apparatus including a monitoring unit which identifies a communication flow where data loss has occurred, calculates modifications for settings for communication control used for a queue corresponding to the identified communication flow, and transmits to the communication apparatus a modification command including the modifications, and the relay unit modifies settings for communication control using the queue corresponding to the identified communication flow on the basis of the modifications included in the modification command.

Communication system, communication control method, and communication apparatus

A communication device: stores flow condition information for identifying a flow and flow counter information that indicates, for each flow, an input flow volume of a flow inputted to the communication device, and an output flow volume of a flow outputted by the communication device; identifies a flow to which data inputted to the communication device belongs, with reference to the flow condition information; updates the input flow volume of the flow in the flow counter information; identifies a flow to which data outputted by the communication device belongs, with reference to the flow condition information; updates the output flow volume of the flow in the flow counter information; and identifies a flow in which a communication anomaly has occurred on the basis of results of a comparison process for comparing the input flow volume to the output flow volume with reference to the flow counter information.

Communication device, communication system, and communication method

A transfer device transfers communication data, comprising: a search unit having a first search means that includes a first table and a first search circuit, the search unit referring to the first table using the first search circuit to search for the first transfer destination information from the first destination information; a search control unit that is a reconfigurable mechanism that creates search designation information and executes a first search designation information creation process of creating first search designation information; a control unit that controls the search unit and creates in the search unit at least a second search means including a second table and a second search circuit, the control unit controlling the search control unit to add to the search control unit a second search designation information creation process; and a transfer unit that receives the communication data and transmits the communication data to a transfer destination.

Transfer device

In a core node, packet related information included in a packet is extracted, a virtual queue length, which is an estimated value of a queue length of a transmission queue addressed to a user in an edge device, is calculated and held on a user basis on the basis of the packet related information and band information of a line between the edge device and the user, and a determination is made, on a user basis, as to whether or not band control is required, on the basis of the virtual queue length and predetermined conditions so as to perform, on the basis of the result of the determination, the band control of the packet addressed to the user on a user basis in a packet relay part.

Communication device and communication method

A communication apparatus comprises a CAM, an action determination unit, and a CAM diagnosis unit. The CAM includes, a plurality of entries each storing therein at least a portion of header information of frame, and a search circuit for each entry configured to determine whether or not a search key matches data stored at the entry. The search key is correlated with information indicating whether or not an entry matching the search key and an expected value of a search result including identification information of an entry matching the search key. The CAM diagnosis unit causes the CAM to search for an entry matching the search key. The CAM diagnosis unit diagnoses a failure occurring at the search circuit of an entry to be the test object when the result of the search does not match the expected value of a search result correlated to the search key.

Communication apparatus, and CAM failure diagnosis method

A data transfer apparatus includes a first memory, a second memory, a search unit, and a data transmitting/receiving unit. The first memory holds information that associates a search key with an address. The second memory holds information that associates the address with verification information which is generated by a predetermined generation method based on at least a portion of the search key. The search unit generates the search key based on the received data, obtains, from the first memory, the address that is associated with the generated search key, obtains, from the second memory, the verification information that is associated with the obtained address, and verifies the verification information that is generated by the predetermined generation method based on at least a portion of the generated search key with the verification information obtained from the second memory. The data transmitting/receiving unit executes processing based on a result of the verification.

Data transfer apparatus and data transfer method

The present invention relates to an electronic device including plural circuit board units that can be removed from the electronic device. The electronic device is designed to increase a data transfer rate between the circuit board units by using a circuit board for interconnect for electrically coupling the circuit board units placed in the electronic device, and using a cable for electrically or optically coupling the circuit board units placed in the electric device, or both of the cables.

Communication apparatus with removable circuit boards

The communication device has a frame transfer unit that executes frame transfer via the first communication link and the second communication link, a link confirmation frame sending unit, and a return link confirmation frame monitoring unit. The link confirmation frame sending unit causes the frame transfer processing unit to send a link confirmation frame for use in confirming a normal link status via the first communication link from the communication device to the counterpart communication device. The return link confirmation frame monitoring unit performs fault detection of the first and second communication links by monitoring a return link confirmation frame which is to be returned from the counterpart communication device to the communication device via the second communication link when the counterpart communication device receives the link confirmation frame via the first communication link.

Communication device, communication system, and communication fault detection method

A relay device of relaying a communication packet is disclosed, which comprises: an input module configured to receive the communication packet as an input; a buffer configured to have a plurality of queues and temporarily accumulated the received communication packet; a sorter configured to sort the received communication packet to one of the plurality of queues, depending on a specific value obtained by a predetermined function that gives an aggregate output from an input which is transfer information regarding transfer of the communication packet; and a band controller configured to control a bandwidth for each of the plurality of queues and output communication packets accumulated in the plurality of queues for transmission of the communication packets. This ensures the quality of service, while saving the capacity of the buffer used for the queues.

Relay device and relay method

A system having a plurality of network devices, each including: an interface module including a plurality of physical ports to transmit and receive packets; a computing module configured to execute a computing process with a computational expression using seed information, the seed information including at least one of destination information and source information associated with a received packet; a destination search module configured to, based on the result of the computation, select a physical port for transmission of the received packet from a plurality of candidate ports among the plurality of physical ports; and a modifying module configured to modify the computational expression, wherein the plurality of network devices include preceding-stage and subsequent-stage network devices, the subsequent-stage network device being directly coupled to the preceding-stage network device with physical wiring, and wherein the subsequent-stage and preceding-stage network devices are configured to use different expressions in the computing process.

Device and method for relaying packets

A network routing apparatus in which packet forwarding units for performing a packet forwarding process are arranged in parallel to one another, a packet distribution unit for distributing packets to the packet forwarding units arranged in parallel to one another, a packet rearrangement unit for rearranging outputs of the packet forwarding units are provided in the network routing apparatus, and packet retrieving units for retrieving packet headers in the packet forwarding units are further arranged in parallel to one another.

Network routing apparatus

Computing process with a computational expression is executed using seed information including at least one of destination information and source information associated with a received packet. It is preferable to select a physical port for transmission of the received packet based on the result of the computation. It is also preferable to select a port group for transmission of the received packet based on the result of the computation. Here, the computational expression is capable of being modified. Meanwhile, the physical port for transmission of the received packet is selected from a plurality of candidate ports among the plurality of physical ports. The port group for transmission of the received packet is selected from among a plurality of port groups including a mutually different candidate port.

The present invention relates to a packet transfer unit, which comprises a search key memory that stores a search key for a transfer destination of a packet and verification information generated from the search key, in association with a storage location of transfer information memorized in a transfer information memory, wherein a transfer information acquisition unit searches the search key memory by using the search key generated based on the header information and the verification information generated from the search key, acquires storage location information of the transfer information from the search key memory when a match with the search key and the verification information memorized in the search key memory is found, and acquires the transfer information stored in the transfer information memory based on the acquired storage location information, and wherein a transfer unit transfers the packet based on the acquired transfer information.

Packet transfer unit

The present invention is directed to rapidly replacing an output destination port with a bypass port and replacing packet output header information with bypass header information when a port accommodated by a router within an IP or MPLS network becomes faulty. The present invention provides a packet forwarding apparatus that accommodates two output ports. The packet forwarding apparatus is embodied in a structure having an element for storing the output information about each of a plurality of pieces of input header information, an element for storing the output information about an output port that is associated with input header information and used as a bypass in the event of a fault, and an output information address rewrite processor for writing, in the event of an output port failure, the output information address associated with an output port that should serve as a bypass.

Method for high speed search tables switching and packet forwarding apparatus

Growing community of inventors

Hadano, Japan

Kazuo Sugai