Fujitsu Corporation

Katsumi Imamura

Hideyo Fukunaga

Yasushi Kurokawa

Tsutomu Noguchi

Yoko Ohta

Takeshi Sumou

Hiroshi Tomonaga

Yoshito Kachita

Akihiro Hata

Yoko Watanabe

Junichi Kawaguchi

Hideyuki Kudou

Naoya Matsusue

Seishiro Taniguchi

The packet transmission device including: a first and a second storage module to store a token value; a token controller to add a predetermined token value to a first total token value, and subtract a predetermined token value from the first total value in response to the output of the packet; an overrun state controller to add an excess of the first total token value over a predetermined upper limit value to a second total token value, in the case where the first total token value added by addition control is greater than or equal to the predetermined upper limit value; and an underrun state controller to subtract a predetermined token value from the second total token value and add the subtracted token value to the first total token value, in the case where the subtracted first total token value is less than the predetermined upper limit value.

Packet transmission device and packet transmission method

The packet forwarding apparatus of the present invention includes a packet buffer for temporarily storing packets to be forwarded, a timer for measuring the time of every predetermined unit period, a plurality of first queues corresponding to each of a plurality of address groups that form the packet buffer, a plurality of second queues that are provided corresponding to the property of the packets, a first controller for executing the writing of the packets, and a second controller for executing the discarding of the packets. According to this invention, through managing the first queues and the second queues, packets in the packet buffer can be discarded without the packets being read from the packet buffer.

Packet forwarding apparatus and method for discarding packets

An aspect of the embodiment utilizes a selection circuit that includes a first storage circuit for storing information of m&#xd7;n bits each corresponding to a choice. The storage circuit indicates whether the corresponding choice is in a selectable state or not. A first round robin circuit for executing a round robin process on the second storage circuit selects one of the bits contained in the corresponding bit string and indicates that a choice is in a selectable state. A second round robin circuit executes the round robin process on the bit string having the m-bit width to select one of the bits indicating that the corresponding choice, and a control circuit controls the first and the second round robin circuit.

Selection circuit and packet processing apparatus

A packet relaying apparatus includes queues holding packet information, and queue control units controlling dequeueing. The dequeueing means transmission of packet information from a queue of a previous stage to a queue of a next stage. The packet relaying apparatus further includes a packet information control unit that, on receiving packet information to be dequeued at the time of dequeueing, returns discard information and data volume corresponding to the received packet information, a first bandwidth adjusting unit that, on determining that the received packet has been discarded, discards the packet information, maintains a usable bandwidth, and transfers the discard information and the data volume to the previous stage, and a second bandwidth adjusting unit that, on receiving the discard information and the data volume from the next stage, adds the data volume to the usable bandwidth and transfers the discard information and the data volume to a previous stage.

Packet relaying apparatus and packet relaying method

A shaper circuit includes a storage part storing a current token, an add token, and a max token, a subtraction part subtracting a packet length of a dequeue target from the current token stored in the storage part and storing the current token in the storage part, an addition part adding the add token stored in the storage part to the current token stored in the storage part at constant periodic intervals and storing the current token in the storage part, a comparison part comparing the result of the addition with the max token stored in the storage part and preventing the addition result from exceeding the max token, and a determining part outputting a dequeue permission request. A number of bits in a decimal part of the current token are set and a number of bits in an integer part of the add token are set.

Shaper circuit and shaper circuit combination

When a ringlet with a high frame transfer quality is selected as a switching candidate for each station of a transfer destination from information on frame transfer quality for each ringlet, when it is determined that a fundamental ringlet is in a preceding stage of degradation of the frame transfer quality from information on the frame transfer quality of the fundamental ringlet, and if the fundamental ringlet is different from the switching candidate, a ringlet for transferring a frame to a station of the transfer destination is switched from the fundamental ringlet to the switching candidate.

Method, apparatus, and computer product for switching ringlets

A packet transmission device improved in packet transmission efficiency. Each packet input processor generates a pointer and identifies a packet type with respect to a received packet, and generates identification data including the pointer and the packet type identification result. A memory access controller detects a header readout amount of the packet based on the packet type identification result, generates first readout data including the header readout amount and a readout pointer indicative of a storage location of the packet in a shared memory, and adaptively reads out header data of the packet from the shared memory in accordance with the first readout data. A protocol processor analyzes the destination of the read header data, and a packet updater updates the old destination address of the packet to a new one to generate a packet with the updated destination address, and outputs the generated packet.

Growing community of inventors

Fukuoka, Japan

Katsumi Imamura