Abstract: A time-point synchronization apparatus (10) includes a time-point management unit (144), a time-gap counter (145), and a time-gap calculation unit (142). The time-point management unit (144) manages an apparatus time point equivalent to a current time point. The time-gap counter (145) records a time gap which is a different between a time point indicated in reception information and the apparatus time point. When a frequency in the time-gap counter (145), corresponding to the time gap corresponding to a latest reception time point corresponding to latest reception information is treated as the highest among all of frequencies indicated in the time-gap counter (145), the time-gap calculation unit (142) synchronizes the apparatus time point to the latest reception time point.

Abstract: A transfer apparatus (10) includes a Pdelay message reception process (101), a Sync/Follow up message reception process (102), an Announce message reception process (103), a Sync reception/transmission guard management process (104), a delay measurement arithmetic process (105), a time synchronization arithmetic process (106), a time selection arithmetic process (107), and a frame transmission process (108). The transfer apparatus (10) monitors a reception state of an Announce message (61) that notifies of time source information for each port, and in a case where, based on monitoring, a state of a time source worsened as in when reliability of time is reduced and the like, a Sync/Follow_up message (51) for time synchronization is made so as not to be transferred. By the above, the transfer apparatus (10) makes a time out of the Sync/Follow_up message (51) occur and worsening of the time source is notified to a different apparatus at high speed.

Abstract: An inference unit (1033) predicts as a prediction parameter value, a future parameter value of a time synchronization parameter used for time synchronization calculation which is calculation for synchronizing times of two devices. When a measured parameter value which is a measured value corresponding to the prediction parameter value is generated with elapse of time, a cumulative distribution table generation unit (1034) calculates as a prediction error, a difference between the measured parameter value and the prediction value. A cumulative probability calculation unit (1036) calculates an abnormality degree indicating possibility that an abnormality is included in the measured parameter value, using the prediction error.

Abstract: A reception unit (210) receives an addition requesting frame for requesting addition of a new flow. A first search unit (241) performs, using a network-information database (280), a first search for searching for a schedule and a path assignable to the new flow without the schedule and the path of each existing flow being changed, when the addition requesting frame is received. A second search unit (242) performs a second search for changing the schedule and the path of each existing flow and searching for the schedule and the path assignable to the new flow, using the network-information database, when the schedule and the path assignable to the new flow have not been found by the first search. A response unit (260) transmits an addition responding frame.

Abstract: A time-point synchronization apparatus (10) includes a time-point management unit (144), a time-gap counter (145), and a time-gap calculation unit (142). The time-point management unit (144) manages an apparatus time point equivalent to a current time point. The time-gap counter (145) records a time gap which is a different between a time point indicated in reception information and the apparatus time point. When a frequency in the time-gap counter (145), corresponding to the time gap corresponding to a latest reception time point corresponding to latest reception information is treated as the highest among all of frequencies indicated in the time-gap counter (145), the time-gap calculation unit (142) synchronizes the apparatus time point to the latest reception time point.

Abstract: A reception unit (210) receives an addition requesting frame for requesting addition of a new flow. A first search unit (241) performs, using a network-information database (280), a first search for searching for a schedule and a path assignable to the new flow without the schedule and the path of each existing flow being changed, when the addition requesting frame is received. A second search unit (242) performs a second search for changing the schedule and the path of each existing flow and searching for the schedule and the path assignable to the new flow, using the network-information database, when the schedule and the path assignable to the new flow have not been found by the first search. A response unit (260) transmits an addition responding frame.

Abstract: An information obtaining unit (53) of a monitoring apparatus (40) obtains from each node, topology map information created in each node by an exchange of information and sharing of information between nodes that belong to a ring network. The topology map information is information that indicates a connection relation between the nodes in the ring network. A topology comparison unit (54) of the monitoring apparatus (40) compares the topology map information obtained from each node by the information obtaining unit (53) with topology definition information retained in a memory (42) beforehand, and determines whether or not a configuration of the ring network is according to design. The topology definition information is information that defines the connection relation between the nodes in the ring network.

Abstract: An information obtaining unit (53) of a monitoring apparatus (40) obtains from each node, adjacent connection information (33) that is created in each node by an exchange of information and sharing of information between the nodes, and keeps the adjacent connection information (33) in a connection information file (38). The adjacent connection information (33) is information that indicates a connection relationship between the nodes. A topology comparison unit (54) of the monitoring apparatus (40) compares connection information included in the adjacent connection information (33) with topology definition information (59) retained in a topology definition file (58) beforehand, and determines whether or not a configuration of a ring network is according to design. The topology definition information (59) is information that defines the connection relationship between nodes in the ring network.

Abstract: Provided are a redundant route calculator that calculates, on the basis of first topology information on a network made up of a plurality of transfer devices, a plurality of shortest routes from a first transfer device to a second transfer device among the plurality of transfer devices, and generates redundant route information; a forwarding database that stores the redundant route information; and a single point-of-failure detector that detects a single point of failure on the basis of the redundant route information and generates second topology information obtained by removing the single point of failure from the first topology information. On the basis of the second topology information, the redundant route calculator calculates an additional route candidate from the first transfer device to the second transfer device. The single point-of-failure detector decides the additional route to register in the forwarding database.

Abstract: A transfer device according to the present invention is a switching device that is one of transfer devices forming a network, and includes: a link state database that holds topology information of the network, and priority of the transfer device and priorities of other transfer devices forming the network to be used in path computation; a shortest path calculating unit that calculates a shortest path from a first switching device to a second switching device among the transfer devices forming the network on the basis of the topology information; and a priority adjusting unit that adjusts the priority of the transfer device on the basis of the shortest path calculated by the shortest path calculating unit and the priority of the transfer device and the priorities of the other transfer devices, wherein the priority adjusting unit adjusts the priority of the transfer device so that the number of overlaps with priority of another transfer device that is included with the transfer device in a shortest path from on

Abstract: An information obtaining unit (53) of a monitoring apparatus (40) obtains from each node, topology map information created in each node by an exchange of information and sharing of information between nodes that belong to a ring network. The topology map information is information that indicates a connection relation between the nodes in the ring network. A topology comparison unit (54) of the monitoring apparatus (40) compares the topology map information obtained from each node by the information obtaining unit (53) with topology definition information retained in a memory (42) beforehand, and determines whether or not a configuration of the ring network is according to design. The topology definition information is information that defines the connection relation between the nodes in the ring network.

Abstract: A transfer device according to the present invention is a switching device that is one of transfer devices forming a network, and includes: a link state database that holds topology information of the network, and priority of the transfer device and priorities of other transfer devices forming the network to be used in path computation; a shortest path calculating unit that calculates a shortest path from a first switching device to a second switching device among the transfer devices forming the network on the basis of the topology information; and a priority adjusting unit that adjusts the priority of the transfer device on the basis of the shortest path calculated by the shortest path calculating unit and the priority of the transfer device and the priorities of the other transfer devices, wherein the priority adjusting unit adjusts the priority of the transfer device so that the number of overlaps with priority of another transfer device that is included with the transfer device in a shortest path from on

Abstract: Provided are a redundant route calculator that calculates, on the basis of first topology information on a network made up of a plurality of transfer devices, a plurality of shortest routes from a first transfer device to a second transfer device among the plurality of transfer devices, and generates redundant route information; a forwarding database that stores the redundant route information; and a single point-of-failure detector that detects a single point of failure on the basis of the redundant route information and generates second topology information obtained by removing the single point of failure from the first topology information. On the basis of the second topology information, the redundant route calculator calculates an additional route candidate from the first transfer device to the second transfer device. The single point-of-failure detector decides the additional route to register in the forwarding database.