Fujitsu Corporation

Nobuhiro Rikitake

Koji Takeguchi

Hirotaka Morita

Mitsumasa Matsuike

Hideki Matsui

Kazuhiro Ohnuma

Ryuichi Moriya

Satoshi Miyazaki

Kazuto Nishimura

Masahiro Yoshimoto

Motoshi Hamasaki

Katsuya Kitamori

Toshimichi Fukuda

Ryuchi Moriya

Toshifumi Yokoyama

Ken Mizukura

A packet processing apparatus includes a memory, a processor, a first gate, and a second gate. The memory stores a plurality of allocation patterns for allocating an upstream or downstream of a link direction for each subframe within a predetermined period. The processor obtains a periodicity pattern of a high-priority packet for each of time slots within the subframe. The first gate opens and closes, for each of the time slots within the subframe, output of the high-priority packet. The second gate opens and closes, for each of the time slots within the subframe, output of a low-priority packet. The processor sets gate states of the first gate and the second gate for a predetermined time slot within the subframe in the same link direction as the periodicity pattern to a priority state in which the high-priority packet is preferentially output according to the periodicity pattern.

Packet processing apparatus and packet processing method

A data transmitting device coupling to a plurality of nodes in a network includes a plurality of communication paths, the data transmitting device includes a memory and a processor coupled to the memory configured to set a routing table based on a command that designates a first communication path included in the plurality of communication paths, to detect a link failure occurred in the network, and when the link failure has occurred at a first location between the data transmitting device and a first node adjacent to the data transmitting device on the first communication path, to modify the routing table so that data are to be transmitted to a second node on a second communication path different from the first communication path, and when the link failure has occurred at a second location that differs from the first location in the network, to maintain the routing table.

Data transmitting device, data transmitting method and non-transitory computer-readable storage medium

In a communication apparatus, based on the relationship among a first port for outputting frames including tag information, a frame destination address, and bandwidth specified to the first port, a controller generates threshold value information to be associated with a second port to which the frames including tag information are input. With respect to the frames input from the second port, a reception processor measures a reception rate according to the tag information and the frame destination address, and selects, based on the reception rate and the threshold value information, frames to be preferentially discarded at the first port.

Communication apparatus and method

An apparatus controls congestion in a communication network. The apparatus includes a plurality of ports configured to transmit and receive frames. The apparatus stores a traffic volume of each of the plurality of ports. The apparatus detects congestion in the communication network, based on frames that are received via the plurality of ports. Then, the apparatus determines one or more ports that receive frames causing the detected congestion, based on the traffic volumes of the plurality of ports.

Apparatus and method for controlling congestion in a communication network

A switching apparatus having a plurality of ports, includes: switch information storage to store an output port identifier for a combination of an input port identifier, an input virtual path identifier, and a destination address; a detector to detect a first input virtual path identifier and a first destination address assigned to an input packet; a searcher to search the switch information storage for a first output port identifier based on a first input port identifier that identifies a port to which the input packet has been input, the first input virtual path identifier, and the first destination address; and a packet switch to transfer the input packet to a port identified by the first output port identifier.

Switching apparatus and method for setting up virtual LAN

A frame concatenation apparatus includes a storage unit to store a plurality of frames to be transmitted, a generation unit to generate a concatenated frame including the plurality of frames read out from the storage unit and serially concatenated, and including frame length information on each frame attached thereto, and an attachment unit to attach information for establishing synchronization with a receiver of the concatenated frame, to the concatenated frame.

Frame concatenation apparatus

A communication system includes a first communication apparatus including one or more first processors that determine a first bandwidth variance for each flow, based on a requested bandwidth variance amount and a surplus bandwidth of a physical line, and a first transmitter that transmits the first bandwidth variance to an adjacent apparatus; and a second communication apparatus including one or more second processors that set the received first bandwidth variance as a requested bandwidth variance amount for the second communication apparatus and determine a second bandwidth variance for each flow from the first bandwidth variance and the surplus bandwidth, and a second transmitter that transmits the second bandwidth variance to an adjacent apparatus.

Communication system and communication apparatus

In order to increase the efficiency of large-capacity transmission, the continuity of divided signals generated by dividing a multiplexed signal is maintained and the original large-capacity multiplexed signal is restored. A signal dividing section divides a multiplexed signal to generate a plurality of divided signals in the STS or STM transmission interface format. A guarantee information adding section adds guarantee information for guaranteeing the continuity of the divided signals to each of the divided signals to generate transmission signals. A signal sending section sends the transmission signals via a transmission line in the transmission interface format. A signal receiving section receives the transmission signals. A signal restoring section restores the multiplexed signal by constructing the divided signals on the basis of the guarantee information.

Transmission system

A data recording system comprises a first memory, a counting unit for counting the number of data writes to the first memory, and an alarm unit for outputting an alarm if the number of data writes to the first memory reaches a first threshold value. The counting unit writes data of the number of writes, which represents the number of data writes to the first memory, to the first memory or a second memory. The alarm unit outputs an alarm based on the data of the number of writes, which is written to the first or the second memory.

Data recording system

Communication nodes respectively comprise a function for transmitting/receiving a digital wrapper frame. SDH devices transmitting/receiving an SDH frame are connected to some of the communication nodes, and Ethernet devices transmitting/receiving an Ethernet packet are connected to some others of the communication nodes. An SDH frame and an Ethernet packet are stored in a payload of a digital wrapper frame, and transmitted between communication nodes. A network management device manages a connection relationship among the communication nodes, and paths set up on a digital wrapper network. The communication nodes respectively transfer a digital wrapper frame in accordance with an instruction from the network management device.

Communications system, and communication device and network management device, which are used therein

In a state where although the setting of a line between a transmitting station and a receiving station is completed, no signal is transmitted, a test signal in a prescribed format is transmitted from the transmitting station. By transmitting the test signal, no signal disconnection is detected by each alarm detection point, and no alarm occurs. When a regular signal is transmitted from the transmitting station to the receiving station, the test signal is automatically switched to a regular signal on the transmitting station side.

Transmission device

Proposed is an optical clock distribution system in the WDM network, which particularly relates to a system to control clock synchronization between optical transmission devices constituting an optical communication network. The optical clock distribution system includes an optical clock generator converting a clock signal of PRC (Primary Reference Clock) level into an optical clock signal having a wavelength &#x3bb;a wavelength multiplexer wavelength-multiplexing the optical clock signal having wavelength &#x3bb;together with other optical wavelength data; and a wavelength-demultiplexer provided in a unit of the network, wavelength-demultiplexing the optical clock signal having wavelength &#x3bb;wherein the other optical wavelength data are processed in the unit of the network using the wavelength-demultiplexed optical clock signal having wavelength &#x3bb;as a reference clock.

Optical clock signal distribution system in WDM network

A network synchronization controller and method for effectively preventing a timing loop from happening in a synchronous network. A clock status message controller, disposed in each network element on the network, produces and sends clock status messages which are each composed of clock quality data and synchronization control data. The clock quality data indicates the quality level of a clock signal that each network element supplies to its neighboring network elements. The synchronization control data contains information to be used to make the network synchronized with a single reference timing source. A clock selector chooses one of the clock signals received from other network elements, based on the clock status messages received along with the clock signals.

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Kawasaki, Japan

Nobuhiro Rikitake