Nippon Telegraph and Telephone Corporation

Fujitsu Corporation

Hiroto Takechi

Katsuhiro Araya

Hideki Maeda

Masahiro Yokota

Masaaki Inami

Masatoshi Namiki

Hiroki Kawahara

Daisaku Shimazaki

Yasutaka Sugano

Takeshi Seki

Katsumi Shimada

Takafumi Hamano

Motohiro Tsuji

Kenichi Aoyagi

A transmission side transmission device includes: a first transmitter including a first switch; and a second transmitter including a second switch. A main signal is input to either the first transmitter or the second transmitter. The main signal input to the first transmitter is a first main signal and the main signal input to the second transmitter is a second main signal. The first transmitter and the second transmitter are configured such that, when the first transmitter detects a fault in the input first main signal: the second transmitter outputs the input second main signal to the first transmitter; and the first transmitter outputs the input second main signal via a first selector.

Transmission side transmission device and redundancy method of transmission side transmission device

A transmission side transmission device includes a first transmitter including a first switch and a second transmitter including a second switch. When the first transmitter detects a fault in the first main signal, the second transmitter outputs a duplicated signal of the second main signal to the first transmitter. The first selector of the first transmitter selects and outputs a duplicated signal of the input second main signal. When the second transmitter detects a fault in the first switch, the second transmitter selects and outputs the second main signal.

Transmitting side transmission device, receiving side transmission device, redundancy method of transmitting side transmission device, redundancy method of receiving side transmission device, program, and transmission device

A monitoring control unit () of an OXC () stores a management table () in which pieces of information regarding a modulation mode, an FEC, and a frame mode of an optical signal are associated with each other, and sequentially changes the modulation mode, the FEC, and the frame mode according to the management table () upon an LOS alert from a relay-side optical input/output unit () or an LOF alert from a DSP () being input thereto. Upon successfully receiving an appropriate optical signal according to the change, the monitoring control unit () acquires transmission source information included in the optical signal, and detects an occurrence of erroneous connection of an optical transmission line in an OXC (), which serves as a relay apparatus, when the acquired transmission source information indicates an optical cross-connect apparatus that is a transmission source different from an original transmission source.

Optical cross-connect device, optical transmission system, and optical transmission line connection error detection method

A transmission device () includes a flow table () that stores identification information about an uninterruptible target flow; a transmission-side identification unit () that identifies whether a received packet is from the target flow or a non-target flow based on whether the received packet matches the identification information about the target flow stored in the flow table (); a tag application unit () that applies, to packets from the target flow, an uninterruptible identifier indicating that the packets are from the target flow and a sequence number for distinguishing the packets from other packets; and a branch unit () that branches the packets from the target flow processed by the tag application unit () into packets to be transferred to an active path () among redundant routes and packets to be transferred to a backup path () among the redundant routes.

Transmitting device, receiving device, packet transfer system,packet transfer method, and packet transfer program

[Problem] whether optical input interruption detected by an OXC device is due to an external failure from an upstream side or an internal failure of the OXC device in a transponder device connected to the OXC device using an optical transmission line, and this determination is implemented at low cost. [Solution] An optical transmission system (A) is configured by connecting a plurality of OXC devices (A) using optical fibers () between transponder devices (A) that relay optical signals transmitted to/from terminals (). The OXC device (A) includes an OSC part () and a monitoring control part (). The OSC part () outputs wavelength information on an optical signal in which optical input interruption has occurred and path information on a path of an optical fiber () in which the optical input interruption has occurred, at the time of detecting the optical input interruption from the optical fiber (). In accordance with the wavelength information and the path information that have been output as above, the OXC device (A) includes an AIS generation part () that generates an AIS signal including both pieces of information on the wavelength and the path of the optical signal relating to the optical input interruption and alarm information relating to both the pieces of information.

Optical transmission system and optical transmission method

A frame transmission apparatus includes multiple ports provided in a line unit, and a setting control unit. The setting control unit checks the normality of the frame transfer state within the apparatus by transferring a maintenance management frame from a first port to a second port within the apparatus. When the first port is a logical port configured by link aggregation of multiple physical ports, the setting control unit selects each of the multiple physical ports as a transmission source port and transfers multiple maintenance management frames from the multiple physical ports to the second port.

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Musashino, Japan

Hiroto Takechi