Abstract: 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.

Abstract: 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.

Abstract: A network anomaly detection apparatus configured to detect an anomaly of a network to be monitored based on received flow statistical information, the network anomaly detection apparatus including a processor, a memory, a statistical information collection unit, an anomaly detection unit and scenario information. The statistical information collection unit configured to receive flow statistical information aggregated from header information of packets in the network and collect the flow statistical information in a flow statistical information storage unit. Scenario information including a scenario in which a time-series sequential relation of events concerning a plurality of flows is defined.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A network relay system includes a plurality of communication devices 1000. Each of the communication devices includes a data plane 20 that transfers an input packet according to routing information, and a control plane 1100 having a processing unit 1110 that learns the routing information, and a control system repeater 1120. The data planes 20 of the respective communication devices can realize a non-blocking communication therebetween. Also, the control system repeater 1120 of an operational system receives the routing information from the processing unit 1110, sets the routing information for the data plane 20 of the subject communication device, and transmits the routing information to the control system repeater 1120 of the other communication device 1100-2. The control system repeater 1120 of a standby system receives the routing information, and sets the routing information for the data plane 20 of the subject communication device.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.