Alaxala Networks Corporation

Nec Corporation

Teruo Kaganoi

Shinichi Akahane

Takeki Yazaki

Takeshi Aimoto

Kazuo Sugai

Mitsuru Nagasaka

Yasuhiro Kodama

Naoya Kumita

Akio Harasawa

Tomohiko Kouno

Tomohiko Kohno

Tetsuya Nagata

Nobuhito Matsuyama

Toshiyuki Kanoh

Shinsuke Suzuki

Mitsuo Yamamoto

Naohisa Koie

Dai Shizume

Takashi Nagumo

Yasuyuki Ikegai

Masashi Uchiya

Shinich Akahane

It is intended to reduce a power consumption without degrading a communication quality of a packet transfer device. One or more of a receiver, a switch unit, and a transmitter include a QoS control circuit for applying QoS control to received packets. There is provided a power saving operation mode that enables power saving operation by changing a grain size of the QoS control according to a flow rate of the packets, and controlling whether or not to supply an electric power to the QoS control circuit or a part of the QoS control circuit, according to the flow rate of the packets.

Packet transfer device and power supply control method for QoS control circuit

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 network system includes: a core switch; and an edge switch. The edge switch includes: a join message identification unit; and a marking unit. The join message identification unit identifies a join message from among MAC frames from the user network. The marking unit marks mark information to a header of a MAC-in-MAC frame in which the identified join message is encapsulated. The core switch includes: a plurality of input/output ports; a mark identification unit; and a port setup unit. The mark identification unit identifies a MAC-in-MAC frame to whose a header the mark information is marked. The port setup unit associates a multicast group of a join message which is encapsulated in the identified MAC-in-MAC frame, with an input/output port to which the identified MAC-in-MAC frame is input.

Multicast snooping on layer 2 virtual private network

A relay device comprises: a packet type determining unit that determines: whether a received packet is a monitoring packet, sent by a first communication device that monitors a network connection state, set the first communication device as the sending source, and set a second communication device that is monitored as the sending destination; and whether the received packet is a monitoring response packet sent as the response to the monitoring packet with sending source address and destination address of monitoring packet interchanged; a transfer processing unit that receives the monitoring packet and transfers it to a destination; a monitoring unit that monitors receipt of the monitoring response packet within a specified period; and a failure notification packet sending unit that generates a failure notification packet and sends it to a specified destination, when the monitoring response packet is not received within the specified period.

Relay device, network system, and network failure detection method

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 display apparatus including: a collecting unit that collects power consumption information, wherein the power consumption information shows power consumption of a connecting device, and the connecting device interconnects a plurality of communication paths in a computer network; and a display unit that displays power consumption of the computer network, based on the power consumption information and constituent units based on a virtual network which is configured virtually on the computer network.

Assessing conditions of power consumption in computer network

A network system comprises a first communication device having a first address connected, using a network, to a second communication device having a second address. The first communication device includes a monitor frame transmitter configured to generate a monitor frame including the second address as a destination address and the first address as a source address, and to output the generated monitor frame to the network; and a monitoring-response frame monitor configured to monitor reception of a monitoring-response frame sent back from the second communication device. The second communication device includes: a monitoring-response frame transmitter configured to, in response to reception of the monitor frame, generate the monitoring-response frame by exchanging the destination address in the received monitor frame for a source address and the source address in the received monitor frame for a destination address, and output the generated monitoring-response frame to the network.

Network system, layer 2 switch, and method of detecting occurrence of a fault in a network

When burst traffic causes a packet to overflow or to be ready to overflow from a queue, a packet relay apparatus mirrors only the packets to be accumulated in that queue. An outgoing queue management unit copies a packet into a queue in an outgoing queue list and then obtains the length of the queue (step). If the queue length is greater than a mirroring starting threshold, the value of the mirroring on/off flag in the corresponding queue entry is changed to ON (step). If the queue length is smaller than a mirroring stopping threshold, the value of the flag is changed to OFF (step). After the queue length exceeds the mirroring starting threshold until the queue length becomes smaller than the mirroring stopping threshold, only the packets to be output to that queue are mirrored.

Packet relay apparatus

A network system includes: a core switch; and an edge switch. The edge switch includes: a join message identification unit; and a marking unit. The join message identification unit identifies a join message from among MAC frames from the user network. The marking unit marks mark information to a header of a MAC-in-MAC frame in which the identified join message is encapsulated. The core switch includes: a plurality of input/output ports; a mark identification unit; and a port setup unit. The mark identification unit identifies a MAC-in-MAC frame in which a header is marked with the mark information. The port setup unit associates a multicast group of a join message which is encapsulated in the identified MAC-in-MAC frame, with an input/output port to which the identified MAC-in-MAC frame is input.

A switching system includes a data collection device, one or more switching devices. The data collection device is for collection of first data subject to specific processing. The switching devices directly or indirectly connected to the data collection device. At least one of the switching devices includes a determination module that determines whether received data is the first data or is second data which is not subject to the specific processing, and a marking module that puts first marking on the received data determined to be the first data. The switching devices respectively includes a transferring processor that executes a first transfer process for sending the received data to the data collection device when the received data has the first marking, and a second transfer process that sends the received data to the specified destination when the received data does not have the first marking.

Switching system and method in switching system

A network system forms a computer network, and includes: a collecting unit; a calculating unit; and a display unit. The collecting unit collects power consumption information from a connecting device. The power consumption information shows power consumption of the connecting device. The calculating unit calculates power consumption of the computer network based on the collected power consumption information. The calculated power consumption is itemized into constituent units based on a configuration of the computer network. The display unit displays the calculated power consumption.

Network relay arrangements including: multiple ports; MAC address storage; flooding indication storage; plane number management storage; table manager; and frame processor. The table manager: utilizes the plane number management storage to specify current identification information being currently used and next identification information to be used next, with regard to a preset element of the key item for identifying a target of deletion of the information of correlating the transmit port to the MAC address from the MAC address storage; sets the requirement of the flooding operation in registry of a certain information group in the flooding indication storage having the preset element and being correlated to the current identification information; and sets the non-requirement of the flooding operation in registry of a certain information group in the flooding indication storage having the preset element and being correlated to the next identification information.

Network relay apparatus

A packet receiving circuit splits the packet received from a transmission channel into a fixed length of cells and outputs the cells, a search key extracting circuit extracts a predetermined search key from the above-mentioned cells, a CAM performs retrieval based on the above-mentioned search key and outputs a memory address corresponding to the search key, a matching entry address receiving and associative data address transmitting circuit calculates the memory address of an associative data memory based on the above-mentioned memory address and outputs the information stored in the associative data memory as associative data, a search result (associative data) receiving circuit receives the above-mentioned associative data and performs header updating and destination address of the above-mentioned cells, and a packet transmitting circuit outputs the above-mentioned cells in the form of a packet to a transmission channel.

Packet processing unit

A bus switch system having an adapter, a first input and first output register in cascade connection on a data transferring bus of bus switch that comprise input and output shift registers. There is also a bridge, the second input and second output registers are in a cascade connection on the first data transferring bus form a shift register. This allows data to be transferred to an adjacent adapter at one clock cycle, thereby the data transfer is made faster. The data transfer on the first and second data transferring buses is conducted in one direction and input/output control is optimally conducted by first and second control means so that switch control in data transfer is made easier.

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Funabashi, Japan

Teruo Kaganoi