Fujitsu Corporation

Yuji Tochio

Kazuyuki Mori

Toru Katagiri

Yoshio Sakai

Atsuo Ishizuka

Yuji Ishii

Tsuyoshi Yamamoto

Tadashi Ikeuchi

Satoshi Kuroyanagi

Shinya Kano

Tamotsu Akashi

Hiroshi Tomonaga

Yasuki Fujii

Kazuhiro Tanaka

Ichiro Watanabe

Tetsuji Yamabana

Ryoichi Mutoh

Toshiyuki Takauji

Kenji Rikimaru

Akio Endo

An optical transmission device includes: a signal processor, a first frame generator circuit and a second frame generator circuit. The signal processor accommodates a client signal into one or a plurality of time slot sequences among n time slot sequences. The first frame generator circuit generates a frame including the client signal accommodated into a part of time slot sequences among the n time slot sequences. The second frame generator circuit generates a frame including the client signal accommodated into other time slot sequences among the n time slot sequences. The signal processor accommodates the client signal into the n time slot sequences when the first frame generator circuit and the second frame generator circuit are implemented, and accommodates the client signal into the other time slot sequences when the first frame generator circuit is not implemented and the second frame generator circuit is implemented.

Optical transmission device, optical transmission system and method of updating the optical transmission device

A transmission device includes at least one port, first and second transceivers, and a processor. The first transceiver transmits or receives a frame signal to or from one adjacent node within a ring network including a plurality of nodes. The frame signal includes an overhead and a plurality of slots. The second transceiver transmits or receives a frame signal to or from another adjacent node within the ring network. The processor sets port information to the overhead of a frame signal to be transmitted from the first transceiver. The processor acquires slot information from the overhead of a frame signal received by the first transceiver or the second transceiver based on the port information. The processor sets a received data signal in a slot allocated based on the slot information, among the plurality of slots of a frame signal to be transmitted from the first transceiver or the second transceiver.

Transmission device and network system

A communication apparatus includes a receiver configured to receive a signal from a first line, a signal processing circuit configured to perform descrambling processing on the received signal, detect a control signal from the descrambled signal, generate a signal in which an idle signal in accordance with a difference amount between a communication capacity of a second line as a transmission destination and a communication capacity of the first line is inserted in a position where the control signal is detected, and perform scrambling processing on the generated signal, and a transmitter configured to output the scrambled signal to the second line.

Communication apparatus and signal relay method

A transmission apparatus includes: a switch circuit to hold a first protection path provided for a working path in a first network, a second protection path provided for the working path in a second network, and a bridge path provided between a working apparatus to relay traffic on the working path between the first and second networks and a protection apparatus to relay traffic on the first and second protection paths; and a signal processing unit to, upon reception of a first control signal indicating a failure on the working path from the first network, transmit the first control signal to the working apparatus and control the switch circuit in accordance with a second control signal corresponding to the first control signal received from the working apparatus, wherein the transmission apparatus is the protection apparatus, and is provided on a boundary between the first and second networks.

Transmission apparatus and redundancy method

A communication system includes a work path and a protection path that are set between a first transfer apparatus and a second transfer apparatus, one of the work path and the protection path being selected by the first transfer apparatus and the second transfer apparatus according to a control signal that includes first information indicating whether there is a failure in one of the work path and the protection path, and a third path that is activated when the first transfer apparatus or the second transfer apparatus receives a control signal in which the first information has been changed to second information indicating that a failure had occurred in both the work path and the protection path and is selected by the first transfer apparatus and the second transfer apparatus.

Communication system and transfer apparatus

A protection path providing method is used in a network that includes a shared section in which a first protection path corresponding to a first work path to transmit a first traffic and a second protection path corresponding to a second work path to transmit a second traffic are configured. The method includes: transmitting a message that includes information indicating a transmission rate of the first work path via a logical ring, the logical ring being formed using a route for which the first work path is configured and a route for which the first protection path is configured, when a failure is detected in the first work path; and controlling a switch circuit installed in a transmission device provided at an end of the shared section in accordance with the message in such a manner as to transmit the first traffic via the shared section.

Protection path providing method and transmission device

An optical transmission device in an optical transmission network including nodes, provided to one of the nodes, the optical transmission device including: a receiver to receive optical signals which have different wavelengths and are multiplexed, an optical detector to detect a strength of the optical signals, a switch to set switching control information including switching request information, each corresponding to one optical signal of the optical signals, and a transmitter to transmit the switching control information by an optical signal, wherein the switch sets, in information indicating a signal fail, the switching request information corresponding to the one optical signal in the switching control information based on the strength of one optical signal of the optical signals.

Optical transmission device and optical transmission network system

For a frame comprising a payload region in which a client signal is to be accommodated, and an overhead region accommodation location information indicating a location where the client signal is to be accommodated, the frame being able to be processed as an m (m is an integer equal to or greater than 2)-byte cycle multiframe, the location information for the frame is defined as an m&#xd7;n (n is an integer equal to or greater than 2)-byte cycle multiframe; using the location information defined as the multiframe, the location where the client signal is to be accommodated in the payload region is defined; and the client signal is accommodated in the payload region, based on the defined location where the client signal is to be accommodated.

Method of accommodating signals, frame generation apparatus, frame reception apparatus, and transmission system

An object is to simplify a process performed due to a failure recovery. To realize this object, the transmission apparatus includes a determining unit that determines, when a transmission apparatus receives a frame from each ring in a network including multiple rings in which a part of each ring is shared, whether failure information indicating that a failure has occurred in one of the rings is contained in one of the received frames. The transmission apparatus also includes a mapping unit that maps a frame that is determined by the determining unit to contain the failure information, onto a shared frame that is a frame used in a shared portion in the multiple rings. Accordingly, the process performed due to a failure recovery can be simplified.

Transmission apparatus, failure recovery method, and network system

A connection node is included in a connecting part of a plurality of rings in a ring network. The connection node includes a failure detecting unit, an optical-signal processing unit, an ODU switch, and an optical-signal processing unit. The failure detecting unit detects failure in the connecting part. The optical-signal processing unit receives data transmitted from another node on a ring to which the connection node belongs. Upon detection of the failure, the ODU switch determines whether to pass the data or return the data in reverse direction from the connection node depending on a destination to transfer the received data, and sets a transmission path of the data based on a result of the determination. The optical-signal processing unit transfers the data in accordance with the set transmission path.

Communication control device and communication control method

An HO ODU signal input to an optical transmission apparatus is disassembled into LO ODUs. LO ODUs specified to form an aggregated ODU are disassembled not into individual LO ODUs but into a unit of an LO ODU group that forms an aggregated ODU. Clock extraction and an alarm process are performed not for the individual LO ODUs but for each aggregated ODU. This eliminates the need for a hardware configuration for performing the clock extraction and the alarm process in units of LO ODUs, leading to saving of hardware resources.

Optical transmission apparatus

A communication apparatus used as a first communication apparatus in a communication system having a ring network, the communication apparatus including: a storage unit configured to store information indicating a correspondence between a state of a path provided on the ring network, a state of a first link established between the first and third communication apparatuses, a state of a second link established between the second and third communication apparatuses, and a direction of forwarding the data; and a control unit configured to monitor links that are included in the ring network, and presence or absence of a failure occurring in each of the first and second links, and determine a direction of forwarding data to which path identification information corresponding to the third communication apparatus is added based on a result of the monitoring and the information stored in the storage unit.

Communication apparatus, system, and method

In a multi-ring communication network, first and second rings include first and second connection nodes, respectively, that are adjacently connected to each other. The first connection node receives, from adjacent nods, traffic information storing a pair of input and output node identifiers in association with each of storage areas included in a frame to be transmitted, where the input node identifier identifies an adjacent node from which data is inputted, and the output node identifier identifies an adjacent node to which the data is outputted. When the received traffic information includes the output node identifier identifying the second connection node, the first connection node sets a plurality of redundant path segments each including the second connection node, based on the received traffic information, where the plurality of redundant path segments includes a currently-used path segment.

System and method for setting redundant path segments in a multi-ring communication network

A data relay apparatus for data relay in a ring-type network for data including a path identifier which is transferred according to the path identifier, receives the data; stores the path identifier that is used to determine a data path in which the data is transferred in the ring-type communication network in association with a reception direction and a transmission direction of the data; compares the path identifier included in the received data and the path identifier stored by an information storing part to determine a path for receiving and transmitting the data and switches the transmission direction of the data based on a reception direction of a failure notification message notified when a communication failure occurs and whether a switching inhibition message transmitted concerning the communication failure is received; and transmits the data in the switched transmission direction.

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Kawasaki, Japan

Yuji Tochio