Nippon Telegraph and Telephone Corporation

Shokei Kobayashi

Takuya Oda

Akira Hirano

Takafumi Tanaka

Fumikazu Inuzuka

Seiki Kuwabara

Seiji Okamoto

Kei Kitamura

Tetsuro Inui

Hideki Nishizawa

Wataru Kawakami

Yoshiaki Yamada

Kengo Shintaku

A transfer device includes a detection unit configured to detect a sign of a failure in a link between transfer devices, and a management unit configured to update a routing table to lower a priority of a path via the link when the sign of the failure is detected by the detection unit.

Failure transfer apparatus, failure transfer system, and failure transfer method

An estimation method includes: generating information regarding success or not success in a connectivity checking test between 'N' nodes in a case in which a failure occurs in a verification target path including the nodes, the information being generated as pattern information for each failure location; selecting “M” network devices from among a plurality of network devices in accordance with occurrence of the failure; executing the connectivity checking test between the selected network devices; comparing a checking result of the connectivity checking test with pattern information that satisfies “N=M” in the pattern information; and estimating the failure location in the service path based on the failure location associated with the pattern information in a case in which the pattern information that satisfies “N=M” matches the checking result.

Service path failure location estimation method, apparatus, and program

A fault diagnosis unit () of a fault diagnosis apparatus () performs a fault diagnosis of a communication network () with a probabilistic inference algorithm using information on the communication network () having been gathered by an NW monitoring unit (). A diagnosis result determining unit () determines test items for confirming and determining a diagnosis result of the fault diagnosis. A test performing unit () performs a confirmation test of the determined test items. The diagnosis result determining unit () determines a likelihood of the diagnosis result of the fault diagnosis based on a result of the confirmation test.

Diagnostic apparatus

An adapting device according to an embodiment includes: a first storage unit configured to store correspondence information representing a correspondence relation between processing requested by a higher-level system and a method for implementing the processing in a lower-level system; a conversion unit configured to convert a processing request from the higher-level system to the lower-level system into a processing procedure capable of being implemented in the lower-level system and supply the processing procedure to the lower-level system; and an additional information processing unit configured to generate additional information to be supplied to the lower-level system together with the processing procedure. The conversion unit described above converts the processing request into the processing procedure based on the correspondence information, and the additional information processing unit described above includes, in the additional information, relation information representing a relationship between the higher-level system that is a request source and the lower-level system that is a request destination.

Adaptation apparatus

An optical transmission system including an optical transmission device and an optical reception device that receives, via an optical transmission line, a signal transmitted from the optical transmission device, the optical transmission system including a transmission-mode selection unit that selects transmission mode information in descending order of priority out of transmission mode information, which is combinations of a plurality of parameters concerning transmission performance, the transmission mode information being a plurality of kinds of the transmission mode information common to the transmission performance of the optical transmission device and the optical reception device, a signal transmission unit that transmits, to the optical reception device, a signal modulated based on the selected transmission mode information, and a signal reception unit that receives the signal and modulates the received signal based on the transmission mode information selected by the transmission-mode selection unit.

Optical transmission system and transmission mode selecting method

A failure location estimation apparatus sets partial networks obtained by dividing a network into one or more networks, and verifies connectivity of a path for each of combinations of terminal nodes for each of the partial networks. The failure location estimation apparatus selects some or all combinations of the combinations of terminal nodes determined to have an abnormality in connectivity for each of the partial networks, and verifies connectivity of a path for each of combinations of nodes included in a selected node connection that is the selected combinations of terminal nodes. The failure location estimation apparatus estimates a failure location in the network based on a verification result of connectivity of each of the combinations of nodes.

Malfunction point estimation method and malfunction point estimation apparatus

A communication system transmits relay data through a communication path including a plurality of sections in which different communication schemes are used. A relay communication device is provided between a first section and a second section which are adjacent sections. The relay communication device includes a receiving unit receiving the relay data from the first section through a frame of a first communication scheme, and a relaying unit configuring, in a frame of a second communication scheme used to transmit the relay data to a relay destination, signal quality information representing signal quality calculated for a physical link in each of the sections through which the relay data is transmitted before arriving at the relay communication device, and outputting the frame of the second communication scheme to the second section.

Signal quality information notification method and relay communication apparatus

A state estimating device includes a pre-processing unit and an estimating unit. The pre-processing unit acquires data representing at one or more of a phase of a signal transmitted from a transmission unit of a transmission device and received at a reception unit of another transmission device via a transmission path, a reception strength, a reception quality, a voltage after conversion into an electric signal, and a signal processing parameter used in reception processing, and processes the acquired data into feature data to be used for state estimation. The estimating unit estimates a state of the transmission path, an abnormal state of the transmission unit, or an abnormal state of the reception unit, on the basis of the feature data.

State estimating device and communication system

There is provided an optical transmission system in which a plurality of optical transmission and reception apparatuses perform 1-to-N transmission and reception of optical signals (N is an integer equal to or greater than 1), the optical transmission system being configured to select a communication condition that includes at least a modulation scheme or a baud rate and is a communication condition when each of the optical transmission and reception apparatuses performs transmission and reception in accordance with a transmission line condition that is between any one first optical transmission and reception apparatus and each of second optical transmission and reception apparatuses, which are N grounds, other than the first optical transmission and reception apparatus.

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Musashino, Japan

Shokei Kobayashi