Hitachi, Ltd.

Other

Alaxala Networks Corporation

Hitachi Information Technology Co., Ltd.

Nobuhito Matsuyama

Kazuo Sugai

Takeshi Aimoto

Takeki Yazaki

Shinichi Akahane

Takayuki Muranaka

Yoshihito Sako

Isao Kimura

Masayuki Shinohara

Tomohiko Tanabe

Yoshihiko Sakata

Yuichi Ishikawa

Kenichi Sakamoto

Norihiko Moriwaki

Noboru Endo

Koji Wakayama

Tetsuya Nagata

Teruo Kaganoi

Toshio Doi

Takeshi Furusawa

Mitsuru Nagasaka

Tatsuo Kanetake

Hiroki Yano

Takeshi Kumagai

Mitsuo Yamamoto

Hiroshi Sekino

Takaharu Aoyama

Takashi Nagumo

Tsuyoshi Katoh

Hirokatsu Shioda

Noboru Tanabe

Yukisada Yamakawa

Satoshi Hatanaka

Masashi Uchiya

Toshimi Sugita

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 packet relay apparatus, which is configured to transmit from a mirror port a mirror packet copied from one of a packet to be received and a packet to be transmitted, the packet relay apparatus comprising: a packet receiving module configured to receive a packet from an input port; a security judgment module configured to judge whether or not the packet is possibly one of an attack and an attack sign; a mirror processing module configured to generate, when it is judged that the packet is possibly one of an attack and an attack sign, a replica of the packet as the mirror packet; and a transmitting module configured to transmit the mirror packet from the mirror port.

Packet relay apparatus

Network switching arrangements including: setting an operation mode of a target switching block to a operation mode that is different from an operation mode of a first switching block while the first switching block is handling a switching process, the target switching block being one switching block selected from second switching blocks; performing a switchover process including starting the switching process using the target switching block instead of the first switching block, after completion of setting the operation mode of the target switching block; and copying the switching information held by the first switching block to the target switching block, prior to starting the switching process using the target switching block, after completion of setting the operation mode of the target switching block.

Network switching device

A network relay system includes a plurality of communication devices. Each of the communication devices includes a data plane that transfers an input packet according to routing information, and a control plane having a processing unit that learns the routing information, and a control system repeater. The data planes of the respective communication devices can realize a non-blocking communication therebetween. Also, the control system repeater of an operational system receives the routing information from the processing unit, sets the routing information for the data plane of the subject communication device, and transmits the routing information to the control system repeater of the other communication device. The control system repeater of a standby system receives the routing information, and sets the routing information for the data plane of the subject communication device.

Network relay system and network relay device

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 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

A method of controlling a network switching device is provided. Perform a mode-process including setting the determination-operation mode of a target switching block to a determination-operation mode that is different from the determination-operation mode of the first switching block while the first switching block is handling the switching-determination process. The target switching block is one switching block selected from the second switching blocks. Then, perform a switchover process including starting the switching-determination process using the target switching block instead of the first switching block, after completion of the process of setting the determination-operation mode of the target switching block.

An input interface segments a variable length packet into plurality of fixed length cells and generates an internal switching information based on the header information of the variable length packet. The input interface transmits the information to a switch and, after that, transmits the cells as the following cells of the information to the switch. The switch performs switching processing to the succeeding cells based on the information. Therefore, the information is not added to the cells. When an input interface starts to transmit cells generated from a packet to its destination output interface through the switch, the switch is reserved until all the cells arrive at the output interfaces.

Variable length packet communication device

A network switching device includes packet switching means and clock signal providing means. The packet switching means receive packets sent from any of the plurality of lines, determines forwarding destinations for the received packets, and forwards the received packets. The packet switching means operates synchronized with a provided clock signal. The clock signal providing means provides the clock signal to the packet switching means. The clock signal providing means is capable of switching a frequency of at least a portion of the clock signal for being provided to the packet switching means to multiple different values.

Power-saving network switching device

A packet forwarding apparatus provided with a plurality of line interface units, comprises a routing processing unit for referring to a routing table, based on header information of received packet to specify one of output lines to output the received packet, a flow detection unit for referring to an entry table, in which a plurality of entries with flow conditions and control information are registered, to retrieve control information defined by the entry with a flow condition which coincides with that of the header information of the received packet, and a packet forwarding unit for transferring the received packet to one of the line interface units connected to the output line specified by the routing processing unit. The entry table id divided into a plurality of subtables corresponding to the values of flow attributes associated with the received packets and the flow detection unit retrieves the control information from one of said subtables specified by the value of the flow attribute corresponding to the received packet.

Packet forwarding apparatus with a flow detection table

In one embodiment, a bandwidth monitoring device comprises a packet receiving circuit configured to receive packets; a counter configured to count a total packet length by adding up inputted packet lengths including a packet length of a next input packet and subtracting outputted packet lengths to produce a counted value; a timer configured to time a packet receiving time; a memory configured to store a number of packet receiving times and a number of counted values counted by the counter which correspond to the packet receiving times, respectively; a counter rate-of-change calculating portion configured to calculate a change rate by a first counted value corresponding to an oldest packet receiving time stored in the memory representing an oldest time at which a packet was received and a second counted value corresponding to a latest packet receiving time stored in the memory representing a latest time at which a packet was received; and a determining portion configured to decide whether the next input packet will be discarded based on a probability computed by the change rate and the counted value counted by the counter when the packet receiving circuit receives the next input packet.

Bandwidth monitoring device

Each routing unit of the network routing apparatus includes: one or a plurality of transfer means each for extracting a packet header of a packet received from a line, and one or a plurality of search means each for extracting output destination information using the packet header received from each transfer means; wherein, in each routing unit, one search means is connected to one transfer means, or a plurality of transfer means are connected to one search means, or a plurality of search means are connected to one transfer means, or a plurality of search means and a plurality of transfer means are connected to one another.

A network relaying apparatus and method for routing and transferring packets at high speed. A transfer engine stores the packets received through a network interface in a packet buffer, and stores the header information in a header RAM. A search engine searches the transfer control information including the transfer destination information and the action information in accordance with the header information, and writes it in the header RAM. The transfer engine produces an output packet based on the information stored in the packet buffer and the header RAM and outputs it to the transfer destination. A switch switches the output packet to the routing process of the destination. The transfer engine executes the receiving process and the transmission process, and the search engine executes the input search process and the output search process. Each of these processes is executed by pipelining control using a required table independently.

Growing community of inventors

Hadano, Japan

Nobuhito Matsuyama