Fujitsu Corporation

Kanta Yamamoto

Yasuyuki Mitsumori

Katsuichi Ohara

Michio Kuramoto

Kazuo Takatsu

Yoshinori Nakamura

Hideaki Mochizuki

Haruyuki Takeyoshi

Akihiko Oka

Hiroyuki Homma

Tetsuo Ehara

Koji Hachiya

Masayuki Ono

Yuichiro Katsura

Junichi Kawaguchi

Masaaki Saito

Toshihito Echizenya

Naoya Matsusue

A transmission device includes: a signal receiving part configured to receive a time division multiplexing signal in which a plurality of packets are stored; a separating part configured to separate the plurality of packets from the time division multiplexing signal; an assigning part configured to assign an identifier corresponding to a stored position in the time division multiplexing signal to each of the plurality of packets; and a packet transmitting part configured to transmit at least two packets having different identifiers out of the plurality of packets through a common transmission path.

Transmission device and transmission system for transmitting and receiving time division multiplexing signal in optical transport network

A packet transmission device includes first and second clocks, a communication unit, and first and second synchronization processing units. The communication unit transmits and receives a synchronization packet to and from an external time source device. The first synchronization processing unit synchronizes the first clock with the external time source device in accordance with time information of the synchronization packet. The second synchronization processing unit synchronizes the second clock with the first clock.

Apparatus and method for synchronizing clocks among communication devices

A frame loss measurement device including a receiving unit which receives a measurement frame for measuring a communication path, a measurement unit which, based on the measurement frame received, measures performance of the communication path where the measurement frame is transmitted, and an allocation unit which secures resources of the frame loss measurement device to allocate to the measurement frame to be received.

Frame loss measurement device, communication device, communication system and performance measurement method

When time synchronization between communication apparatuses is performed with PTP, a PTP packet storing a time stamp is transmitted/received. At that time, an RTC is provided in a PTP packet generation unit within the communication apparatus. An RTC is also provided in a PTP packet transmission unit. These RTCs are time-synchronized by a hardware operation based on PPS/System CLK. The RTCs of the PTP packet generation unit and the PTP packet transmission unit are time-synchronized, whereby a highly precise time stamp and correction value for a time can be obtained.

Communication apparatus

An interface board includes a synchronizer that synchronizes a first time that is a time of the interface board to a base time based on a master synchronization signal that is supplied by an external master time source and that defines the base time. The interface board also includes a comparator that compares a phase of a first synchronization signal that synchronizes to the first time with a phase of a shared synchronization signal sent by an interface controller that controls the interface board, and a notifier that notifies another interface board of a comparison result of the comparator.

Communication system, communication interface, and synchronization method

A packet switching system includes a forwarding processing unit determining a destination of an input packet by analyzing the input packet and outputting it as an output packet, the forwarding processing unit comprises an ingress interface card checking if the input packet has a sequential cyclic number and an egress interface card creating a sequential cyclic number and assigning it to the output packet.

Packet switching system

A routing apparatus couples to another routing apparatus using a trunk formed by a plurality of channels, and has a plurality of input and output cards to input and output frames. Each input and output card includes a management table registering a transmitting source address, destination information, and a trunk attribute indicating whether a channel used for a transmission has a trunk structure, a learning request part searching the management table using a transmitting source address within a frame that is transmitted via the channel, and generating and supplying learning request information having information that is obtained by searching the management table to another input and output card, if the channel used for the transmission has the trunk structure, and a registering part registering learning request information supplied thereto in the management table.

Routing apparatus

A packet processing apparatus includes a plurality of communication connecting unit each connected with a communication partner apparatus using one of a work path and a protection path, connecting unit for connecting, using a data bus, the plurality of communication connecting unit with one another; determination unit for, when a packet sent from the communication partner apparatus is received by one of the communication connecting unit, determining whether the packet is a maintenance packet that is used for monitoring a connection state with the communication partner apparatus; and transmitting unit for, when it is determined that the packet is a maintenance packet by the determination unit, transmitting the maintenance packet to the plurality of communication connecting unit using the data bus via the connecting unit.

Packet processing apparatus, interface unit and method thereof

A router controlling a route of packets. The router includes a counter counting an amount of received control packets on a user-identifier-by-user-identifier basis, the control packets being used for managing a network, a discard determining unit comparing a counter value of the counter with a threshold value, and a control packet discarding unit discarding a control packet including a user identifier for which the discard determining unit determines that the counter value exceeds the threshold value.

Router and packet discarding method

When a data word is designated through a network search engine, a FIFO unit, and the like, a relay apparatus according to the invention searches for an associative memory address corresponding to the data word. Even when the associative memory address is internally converted to a contents memory address, the relay apparatus stores the contents memory address by causing it to correspond to a search result corresponding to the contents memory address as well as outputs the associative memory address together with the search result.

Relay apparatus and data control method

A communication system that enhances the efficiency of network operations in response to a request for a transfer bandwidth increased locally. A physical links are installed at a span where a transfer bandwidth is locally increased in a network, and the physical links can cover the increased transfer bandwidth. A load sharing section regards the physical links as one virtual link called a link aggregation, and performs load sharing and outputs data to the plurality of physical links. A collecting section collects data transmitted through the plurality of physical links and outputs the data according to the destination of the data. Any nodes are connected by a link aggregation to configure an RPR ring network having non-uniform transfer bandwidth.

Communication system, communication card, and communication method

A communication method for a network where a plurality of communication devices are interconnected and a plurality of pairs of working channels and backup channels are set in two paths between adjacent communication devices to perform 1:1-protection communications. For information traffic of a type where importance determined by the type of information to be transmitted is relatively high, the 1:1-protection communications is performed by using working channels set in one of the two paths when there is no failure, and by switching to backup channels set in the other of the two paths when a failure is detected. For information traffic of a type where the importance is relatively low, communications is performed by using channels other than the working channels set for the information traffic of a type where importance is relatively high, in the two paths, when there is no failure.

Communication device with 1:1 protection

Efficient packet traffic transmission equipment is provided by enhancing the transmission equipment already implemented in a carrier to have the packet processing function, with a reduced number of cross-connects for 1:n (point-to-multipoint) connection between nodes. Transmission equipment includes a switch board having a cross-connect portion for making a multiplexed packet signal to branch to predetermined paths; and a plurality of interface boards for interfacing the cross-connect portion with a multiplexed signal being transmitted on a path, wherein at least one of the plurality of interface boards is a dedicated interface board having a path switch function of demultiplexing the multiplexed packet signal to each packet to route the demultiplexed packet signal to a predetermined path.

Transmission equipment having a packet switching function

Disclosed is a packet transmitting apparatus for transmitting packets belonging to a plurality of groups having priorities that differ from one another. The apparatus includes a queue controller, which is provided in a scheduling unit, for generating queues on a per-group basis and giving a packet transmit privilege in order, in accordance with the round-robin method, to elements constituting each of the queues, queue by queue; and a packet-transmit group decision unit, which is provided in the scheduling unit, for deciding that a packet transmit group is a group having the highest priority among groups in which a packet corresponding to at least one queue element is awaiting to be transmitted. The queue controller gives the packet transmit privilege to the highest-priority queue element of a queue of the packet transmit group that has been decided and transmits the packet that corresponds to this queue element.

Packet transmitting apparatus

A communications system has two transmission circuits, each transmitting a multiplexed signal in both ways. A repeating installation used therein selects either one of the two transmission circuits and terminates management information contained in a signal which flows through a transmission circuit selected by the selecting unit. The repeating installation sets the other non-selected transmission circuit to be in a high impedance state. The selection and termination are commonly performed for the two transmission circuits, and the repeating installation further extracts the management information transmitted and outputs the management information to be outputted. The management information includes a section overhead having management information concerning a repeating section of the communications system, and the repeating installation does not terminate management information concerning a multiplex section. One of the two transmission circuits includes a spare transmission circuit.

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Kawasaki, Japan

Kanta Yamamoto