Abstract: A bandwidth monitoring device for use in a network for transferring priority packets in preference to non priority packets as far as the amount of the priority packets is within a contract bandwidth established between a network user and a network operator, comprising a bandwidth check result decision unit for detecting whether the bandwidth of the priority packets is less than the contract bandwidth, and a DSCP decision unit for determining that a non priority packet may be transferred as a priority packet when the bandwidth of the priority packets is less than the contract bandwidth thereby to sufficiently use the contract bandwidth.

Abstract: A traffic shaper comprises a cell buffer for temporarily storing an ATM cell arrived thereat, a first calculator for calculating an estimated cell sending time according to a VC contracted bandwidth, a second calculator for calculating an estimated cell sending time according to a VP contracted bandwidth, a binary tree VP sorting circuit for determining VP to be sent in top priority, a binary tree VC sorting circuit for determining VC to be sent in top priority, and a sending circuit for sending a cell in which the determined VP and VC are both brought to a transmittable state. The VP estimated sending time is revised according to the VC estimated sending time.

Abstract: A traffic shaping apparatus calculates a minimum transmission interval, an allowed transmission frame rate of a user frame, and a reference transmission interval for each user according to a minimum transmission frame rate and a peak transmission frame rate specified for each user. The traffic shaping apparatus also calculates a first estimated transmission time according to the reference transmission interval, and a second estimated transmission time according to the minimum transmission interval for each user. The traffic shaping apparatus determines the user having the earliest first estimated transmission time, and determines according to the second estimated transmission time of the user whether a user frame is to be transmitted.

Abstract: A traffic statistical analysis processing unit is provided in a network control apparatus so as to detect an abnormal traffic. When the abnormal traffic is detected, a filter is set to a packet transfer processing unit so as to stop transferring operation of the abnormal traffic. At the same time, abnormal condition sensing information is superimposed on a statistical information packet, and the resulting statistical information packet is transmitted to a traffic analyzing apparatus.

Abstract: A packet forwarding apparatus 200 transmits an inputted packet A to a first output port that is one of a plurality of output ports and transmits a dummy packet A storing the packet length of packet A to the other output port. A shaping unit 100-1 corresponding to the first output port uses the packet length of the packet A and a shaping unit 100-2 corresponding to the port other than the first output port uses a packet length in the dummy packet A so as to control the bandwidth of the packet A to be transmitted, thus controlling the total bandwidth of the packet A.

Abstract: A technique capable of controlling packets to be output to a plurality of ports is provided. Disclosure is made of a packet forwarding apparatus for distributing packets received from a physical port to be transmitted over a plurality of physical ports, which includes a transmitting/receiving unit for transmitting/receiving packets via a physical port, a port group decision unit for deciding a port group corresponding to a plurality of physical ports, and a port group control unit for controlling flow of packets for each port group decided by the port group decision unit.

Abstract: 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.

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: In a device that interworks a VLAN network and an MPLS network, a VLAN ID is associated with an MPLS label. In a device that performs interworking from a VLAN network to an MPLS network, an output MPLS label is determined from a pair of a VLAN ID and the information in the layer 3 or layer 4 header of a packet. The output MPLS label is assigned an independent value for each VLAN. In a device that performs interworking from the MPLS network to another VLAN network, the input MPLS label is associated with a VLAN ID.

Abstract: In a device that interworks a VLAN network and an MPLS network, a VLAN ID is associated with an MPLS label. In a device that performs interworking from a VLAN network to an MPLS network, an output MPLS label is determined from a pair of a VLAN ID and the information in the layer 3 or layer 4 header of a packet. The output MPLS label is assigned an independent value for each VLAN. In a device that performs interworking from the MPLS network to another VLAN network, the input MPLS label is associated with a VLAN ID.

Abstract: A packet communication system of the present invention has first mode, second mode and third mode to apply to input packets. The first mode is a mode that decides priority of the packet by at least one of the address information and the application information, the second mode is a mode that decides priority of the packet by the DS value, the third mode is a mode that decides rewrite the DS value by at least one of the address information and the application information. A control unit of the packet communication system switches a mode to apply an input packet of the first mode, the second mode and the third mode based on the packet header information of the input packet.

Abstract: For setting up a connection belonging to a particular traffic class which does not make bandwidth reservation, information indicative of a priority related to cell discard declared by a source unit is stored in either of nodes in an ATM network corresponding to an identifier of the connection, such that the node selectively performs discard processing on cells belonging to the particular traffic class, when congestion occurs on the connection, in conformity to a predetermined discard condition determined by a relationship between the status of the congestion and the priority. In this way, traffics can be protected for connections having higher priorities even if they do not make bandwidth reservation.

Abstract: A router comprising a priority level distinguishing means for distinguishing the priority level of a packet by referring to the information contained in the header of the packet, a routing table where an output path comprising one or more output lines can be mapped to each level of priority, an output path determining unit that searches the routing table and determines an output path to be used for sending out packets, and a preferential delivery controller that executes delivery control in accordance with the priority level for each output line corresponding to the output path. In response to a fault state in a preferred output line, the router can reroute high priority packets over an alternative output line while maintaining priority. The router may also calculate a distribution ratio to determine the optimal load for each output line for a given packet priority.

Abstract: A flow dubious of an abnormal flow is asked to be specified and flow statistic information of the flow is required to be collected. To comply with such a request, a discard information analyzer of apparatus administrator, for instance, analyzes the number of discard packets, the number of receiving packets or the number of transmitting packets counted by a bandwidth monitor of packet receiver or a bandwidth controller of packet transmitter and in accordance with the result of analysis, automatically sets, in an OUT side flow controller or In side flow controller, information for identifying a flow subject to flow control. Further, the OUT side flow controller or IN side flow controller picks flow statistic information from packets belonging to the object flow by using the set flow identification information.

Abstract: A packet forwarding device with a shaping unit, which is provided with queues for storing high priority packets and queues for storing low priority packets. The shaping unit transmits a packet read out from the non priority queue by giving a high priority when no transmit-wait packet exist in the priority queue even though the time to transmit a packet from the priority queue is reached.

Abstract: When a packet arrives at a shaping unit 500, a discard control unit 510 judges whether to “store” or “discard” the arrived packet. Packets judged to be “stored” are stored into a packet storage FIFO buffer 520 and sent out within a transmission bandwidth greater than the total sum of user-by-user minimum bandwidths. A bandwidth check unit 600 checks bandwidth per user and judges packets that fall within the bandwidth to be high priority packets and packets that fall outside the bandwidth to be low priority packets. If a large quantity of packets are stored into the packet storage FIFO buffer 520, the discard control unit 510 determines that low priority packets are exclusively “discarded,” thus securing high priority packets from being discarded. Thereby, the shaping unit 500 ensures proper packet transmission within user-specific minimum bandwidth.

Abstract: When a packet arrives at a shaping unit 500, a discard control unit 510 judges whether to “store” or “discard” the arrived packet. Packets judged to be “stored” are stored into a packet storage FIFO buffer 520 and sent out within a transmission bandwidth greater than the total sum of user-by-user minimum bandwidths. A bandwidth check unit 600 checks bandwidth per user and judges packets that fall within the bandwidth to be high priority packets and packets that fall outside the bandwidth to be low priority packets. If a large quantity of packets are stored into the packet storage FIFO buffer 520, the discard control unit 510 determines that low priority packets are exclusively “discarded,” thus securing high priority packets from being discarded. Thereby, the shaping unit 500 ensures proper packet transmission within user-specific minimum bandwidth.

Abstract: A packet communication system of the present invention has first mode, second mode and third mode to apply to input packets. The first mode is a mode that decides priority of the packet by at least one of the address information and the application information, the second mode is a mode that decides priority of the packet by the DS value, the third mode is a mode that decides rewrite the DS value by at least one of the address information and the application information. A control unit of the packet communication system switches a mode to apply an input packet of the first mode, the second mode and the third mode based on the packet header information of the input packet.

Abstract: A packet forwarding device with a shaping unit, which is provided with queues for storing high priority packets and queues for storing low priority packets. The shaping unit transmits a packet read out from the non priority queue by giving a high priority when no transmit-wait packet exist in the priority queue even though the time to transmit a packet from the priority queue is reached.

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.