Alaxala Networks Corporation

Hitachi, Ltd.

Takayuki Muranaka

Shinichi Akahane

Nobuhito Matsuyama

Masayuki Shinohara

Isao Kimura

Yoshihiro Nakao

Kazuo Sugai

Mitsuru Nagasaka

Atsushi Serizawa

Masaki Yamada

Tetsuya Nagata

Keiichi Higeta

Hidehiro Toyoda

Takeshi Furusawa

Tatsuo Kanetake

Takeshi Kumagai

Takashi Muto

Yasuhiro Fujimura

Junji Baba

Naohisa Koie

Koyuru Nagao

Takumi Nakaki

Takeshi Matsumoto

Takeshi Gotou

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

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

In a conventional 'distributed' integrated network node architecture, specific judgment processes cannot be executed in any routing and transferring unit. The routing and transferring unit is required to share judgment process related information with an enhanced processing unit or other routing and transferring units. Thus, when using enhanced processing units, manufacturing costs increase, while processing speed decreases when routing and transferring units cooperate. If any flow is disposed during a transfer from a packet transferring unit in a routing and transferring unit to a processing unit, the packet is disposed regardless of packet priority. In the present invention, a packet related to a specific judgment process is always transmitted to a specific routing and transferring unit from a line interface unit. If an inputted flow is over the transferring capacity, the line interface unit analyzes the packet header and determines the type, transport priority, and disposal priority of the packet.

Packet transferring node

This invention provides a data transfer control device for carrying out data transfer using a plurality of transfer resources. The data transfer control device comprises a transfer resource management portion that set the plurality of transfer resources to either one of a transfer-enabled state whereby data transfer is enabled and a plurality of standby states on the basis of a load on the data transfer control device and that manages the plurality of transfer resources so as to assume the set operating status; and a load distribution portion that distributes the data to transfer resources that have been set to the transfer-enabled state. The plurality of standby states are states which data transfer is disabled and which mutually differ at a minimum in terms of at least one of power consumption level and transition time to the transfer-enabled state.

System for setting each transfer module in a network device into one of a plurality of standby states based upon the level of traffic

A transmitter communicates with a receiver and an error corrector corrects bit errors generated during data transmission. The transmitter has a scrambler unit that scrambles data so that a running disparity of 0 and 1 in the input data is substantially zero. A bit-string converting unitthat adds bit data for ensuring a maximum run length of a serial bit string of the scrambled data and converts control information to bit data of a fixed value. A synchronization timing generating unitdivides the transmitted data by a constant interval and converts the transmission data to a data block. A bit-string converting unit extracts a fixed-value bit pattern of the control data from the bit string of the data block, converts the bit pattern to the control information, and discriminates the data and the control information. A descrambler unit reconverts the data-scrambled data to the data before scrambling.

Data transmission equipment and generating method for transmission code

In the case of a 'distributed' integrated network node (architecture), a specific judgment process cannot be executed in any routing and transferring unit. The routing and transferring unit has been required to share such judgment process related information with an enhanced processing unit or with other routing and transferring units. Thus the manufacturing cost has increased when using an enhanced processing unit and the processing speed has been lowered unavoidably when cooperation is required among routing and transferring units. Those have been conventional problems. Furthermore, if any flow is disposed during a transfer from a packet transferring unit provided in a routing and transferring unit to a processing unit, the packet is disposed regardless of the packet priority. This has also been another conventional problem. According to the present invention, however, it is ruled that a packet related to a specific judgment process is always transmitted to a specific routing and transferring unit from a line interface unit. And if a flow is inputted and it is over the transferring capacity between a line interface unit and a routing and transferring unit, the line interface unit analyzes the packet header and determines the type, transport priority, and disposal priority of the packet.

Control device and control method for reduced power consumption in network device

In a data transfer device which cancells an offset of a differential amplifier for amplifying a received signal and an offset caused by characteristics of a differential transmission line and selects optimum conditions such as pre-emphasis amount of an output pre-emphasis circuit, a first chip (transmission side LSI=transfer engine) and a second chip (reception side LSI=multiplexing engine) are connected to each other through differential transmission lineand a SerDes (serializer)and a SerDes (deserializer)are used to make signal transmission, so that optimum setting conditions of an offset amount of an offset cancellation circuit included in an input buffer amplifier and a pre-emphasis amount of pre-emphasis circuit included in an output buffer are decided in training using a training PRBS generatorand a training PRBS comparator

Data transfer device of serializer/deserializer system

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.

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

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.

Growing community of inventors

Kawasaki, Japan

Takayuki Muranaka