Abstract: A signal transmission system comprises: a first circuit; a second circuit; a transmission line configured to transmit data from the first circuit to the second circuit by using a differential signal; a monitor configured to monitor an interval of transmission of the data; and a compensator configured to correct a transmission loss of the differential signal in the interval monitored by the monitor.

Abstract: 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.

Abstract: An apparatus has a receiver module configured to receive packets including multiple different identifiers, an aggregation module configured to classify each packet, which is received by the receiver module into a certain aggregate flow and generate aggregate statistical information including number of packets belonging to the certain aggregate flow, and a statistical processing module configured to perform an updating process arranged to classify the certain aggregate flow into a specific statistical flow and to update statistical information including number of packets belonging to the specific statistical flow based on corresponding aggregate statistical information, the statistical processing module repeating the updating process for multiple aggregate flows, into which packets are classified by the aggregation module, so as to update the statistical information in each of the multiple different statistical conditions.

Abstract: A network relay device for relaying communication for a regular terminal via a port includes an acquiring module, a regular terminal information storing module, and a determination process module. The acquiring module acquires a regular layer 2 address, a regular layer 3 address, regular VLAN information representing a VLAN assigned to the regular terminal, and regular port information representing a port to which the regular terminal is connected. The regular terminal information storing module stores regular terminal information representing a combination of the acquired regular layer 2 address, the regular layer 3 address, the regular VLAN information, and the regular port information. The determination process module determines whether the combination of source layer 2 address, source layer 3 address, assigned VLAN, and reception port of target frame data received via the port is stored as the regular terminal information.

Abstract: A network relay apparatus which conducts data transfer by using a plurality of network LSIs includes a transfer engine unit having at least two network LSIs and a central control unit which controls the operation state of the network relay apparatus. The transfer engine unit includes the network LSIs capable of changing over at least one of a clock and an operation which differ every function block, a load judgment unit for judging a load laid upon each of function blocks in the network LSI, and a frequency voltage control unit for individually changing over at least one of the clock and operation voltage supplied to each function block on the basis of the load judged by the load judgment unit.

Abstract: An internetwork device comprises a receiving module, an inter-device packet transfer interface, an inter-device packet transfer controller, an address translation module, and a transmission module. The receiving module receives a packet from a first network. The inter-device packet transfer interface carries out inter-device packet transfer involving transfer of a packet to or from another internetwork device. The inter-device packet transfer controller controls the inter-device packet transfers such that multiple fragmented packets created from a same original packet are collected by the same internetwork device, the fragmented packets being packets created by dividing a single original packet into multiple parts. The address translation module translates between a local address used within a specific network and a global address used across multiple networks, for at least one of a source address and a destination address of a packet.

Abstract: An extranet direct route allowing extranet forwarding to a directly linked device is written in a layer 2-layer 3-integrated forwarding table. The procedure of introducing a layer 3 address-to-layer 2 address correspondence relation table entry into the layer 2-layer 3-integrated forwarding table searches the layer 2-layer 3-integrated forwarding table with a layer 3 address of the correspondence relation table entry and a layer 3 interface as search keys to retrieve any forwarding entry relating to an extranet direct route as a forwarding destination. The procedure subsequently extracts a VRF of each retrieved forwarding entry and introduces the correspondence relation table entry for the extracted VRF into the layer 2-layer 3-integrated forwarding table.

Abstract: A network controller, capable of high-speed extraction of malicious traffic from networks and determining characteristics of such traffic, includes a unit for accumulating a number of packets for each arbitrary itemset included in the header portions of packets to be transferred, and a unit for determining whether the accumulated value obtained by the accumulating unit exceeds a predetermined threshold, and determines the types of packets to be transferred from accumulated values of the itemset and an itemset different from the itemset when the number of packets exceed a threshold.

Abstract: The network relay device is provided. The network relay device includes: a plurality of ports, each being configured to be connectable with one physical line; a virtual line controller configured to treat a plurality of physical lines, which are respectively connected with the plurality of ports, to constitute a virtual line; and a status check frame controller configured to send via the virtual line a status check frame for use in checking status of a network, which the network relay device is connected with via the virtual line, wherein the status check frame controller changes a frame-sending port to be used to send a next status check frame, in order to avoid continuously using an identical port as both a frame-sending port to send the status check frame and a frame-receiving port to receive the status check frame from another network relay device.

Abstract: The packet relay device includes a clock generation portion adapted to generate a clock signal of prescribed frequency as a standard for operation of the packet relay device; a timer portion adapted to count up a timer value over a first number of clock cycles on the basis of the clock signal; a relay control portion adapted relay received packets while limiting to a prescribed amount of packets the amount of packets forwardable per a predetermined increment of the timer value; and a power control portion adapted to reduce the frequency of the clock signal to 1/n in order to reduce power consumption by the packet relay device. If the frequency of the clock signal has been reduced to 1/n by the power control portion, the timer portion counts up the timer value over a number of clock cycles equivalent to 1/n the aforementioned number of clock cycles.

Abstract: A traffic analysis apparatus includes: a packet transmitter/receiver; a packet aggregating unit, for adding the number of packets that employ the same values for items in a combination that includes one arbitrary item or multiple items in packets obtained by the packet transmitter/receiver; a variety aggregating unit, for adding the number of appearances of different values in the items that are not included in the combination; and a packet estimation unit for, when the total number of packets is greater than a designated threshold value, employing a relationship between the values of the items of the combination formed of one arbitrary item or multiple items, the number of appearances of different values and the threshold value, and estimating the characteristics of the packets for which the number has exceeded the threshold value.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: In an FDB provided for a switch, line information associated with MAC address information is managed separately for sending destination line information and receiving discrimination line information, and provides an incompatibility permission flag of permitting that they are different. Also, a function of rewriting the sending destination line information with a command from a manager is provided and linked with the change of the incompatibility permission flag. While the traffic is moved to a new line at the time of the line switching, this incompatibility is permitted, and even if a frame is received from an old line, the receiving line is not updated based on the frame.

Abstract: Network relay apparatus includes: relay apparatus selector configured to, in response to reception of a join request for a preset multicast group from an external device connecting with the network, refer to information for identifying respective network relay apparatuses on a segment which the own network relay apparatus belongs to, and, at least one of information for identifying the preset multicast group and information for identifying a source, wherein the information for identifying the preset multicast group and the information for identifying a source are included in the received join request, and unequivocally select one network relay apparatus among at least part of the network relay apparatuses on the segment as a designated network relay apparatus according to a predetermined rule, wherein the designated network relay apparatus is assigned to relay a multicast packet to the external device; and a multicast route setter.

Abstract: When the provider edge PE1 detects the occurrence of a failure at the access line AL1, it sends the label withdraw message to the virtual circuit VC1, and when the provider edge PE2 receives the label withdraw message sent via the virtual circuit VC1, the access line AL2 is put to a link down state, and when the customer edge CE2 detects the link down state of the access line AL2, it switches from the normal path to the redundant path.

Abstract: 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 unit 15 that 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 unit 16 divides 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.

Abstract: 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.

Abstract: 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.