Fujitsu Corporation

Seiji Meki

Tomonori Gotoh

Junichi Moriyama

Takashi Yasuda

Satoshi Yasutaka

Shunji Yamada

A relay method includes transmitting, by a first apparatus in a ring network, a first control frame in which information of the first apparatus is stored, through a first port different from a second port where a communication failure is detected; receiving, by a second apparatus in the ring network, the first control frame through a third port, when the communication failure does not occur at a side of a fourth port different from the third port: storing information of the second apparatus in the first control frame; and transmitting the first control frame through the fourth port; and when the communication failure occurs at the side of the fourth port, determining whether a data frame flowing into the ring network is affected by the communication failure for every VLAN (virtual local area network) based on the first control frame; and switching a communication path set in an affected VLAN.

Relay method, relay system, recording medium, and method

An information transmission device includes: ring-ports; an access-port; a communication-path-setting unit to facilitate or cut off communication of the ring-ports or the access-port, based on a communication setting determined such that communication paths having priority levels and assigned with same identifiers have different sections; a control-signal-transmission unit, when a communication failure occurs between one ring-port and another information transmission device, to transmit, from another ring-port, a first control signal for instructing a cutoff of communication of the access-port in the communication path having a low priority level, and transmit a second control signal for instructing a facilitation of communication of the ring-ports; an access-port-control unit, upon receiving the first control signal, to cut off the communication of the access-port in the communication path having the low priority level; and a ring-port-control unit, upon receiving the second control signal, to facilitate communication of the ring-port having non-communication failure.

Information transmission device, information transmission system and information transmission method

A bridge apparatus creates, transmits and circulates pass checking frames having virtual network identifiers in a ring network, and collects a passing/non-passing state of each virtual network identifier. The bridge apparatus creates, transmits and circulates a usage state checking frame in the ring network, and collects a used/unused state of the virtual network identifier of each bridge apparatus. The bridge apparatus creates, transmits and circulates a connection changing frame to change the virtual network identifier having the used state and the non-passing state into the virtual network identifier having the unused state and the passing state. Each bridge apparatus changes the virtual network identifier having the used state and the non-passing state into the virtual network identifier having the unused state and the passing state.

Bridge apparatus and virtual network switching method

The invention relates to a package starting control device determining a moment and a sequence of starting a package corresponding to an individual wavelength to be wavelength-division-multiplexed in a wavelength division multiplex transmission device. An object of the invention is to provide a package starting control device capable of effectively increasing or decreasing the number of wavelengths at low cost without changing a basic structure drastically. The package starting control device is constructed such that operational states of optical modules that generate optical signals wavelength-division-multiplexed into wavelength division multiplexed optical signals are monitored, the optical signal output by packages that generate the optical signals wavelength-division-multiplexed into the wavelength division multiplexed optical signals during a period when any of the operational states is not in a steady state is restricted and the restriction of the optical signal output by one package of the packages each time the period elapses is released.

Package starting control device

A transmission apparatus has units to which main signals are input for subjecting these main signals to predetermined processing and then transmitting them. One of these units is a master unit and the others are slave units and they are interconnected by a clock cable and processor-to-processor cable. Each slave unit detects a synchronization status message that has been inserted into a main signal input from a line and notifies the main unit of this synchronization status message via the processor-to-processor cable. Using synchronization status messages acquired from the slave units and a synchronization status message that has been inserted into a main signal input thereto, the main unit obtains the synchronization status message indicative of the best quality level and adopts, as a master clock, a clock extracted from the main signal into which this synchronization status message has been inserted.

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Nonoichi, Japan

Seiji Meki