Abstract: A transfer device (10) transfers a packet between a first network (31) and a second network connected to a network device (32) via a first communication path and a second communication path, the network device (32) functioning as a gateway for connecting to the first network (31). The transfer device (10) includes a control unit (16, 22). The network device (32) holds correspondence information indicating a correspondence relationship between each of a first communication port for connecting to the first communication path and a second communication port for connecting to the second communication path, and address information regarding a destination of the packet. The control unit (16, 22) transmits, to the network device (32), an update control signal for the network device (32) to update the address information associated with the first communication port in the correspondence information.

Abstract: An object is to provide a communication system, a communication method, a transmission-side switching device, a reception-side switching device, and a program that can carry out network switching of a plurality of L2NWs with a short communication disconnection time without limiting topology. A transmission-side accommodation SW duplicates a frame received from a transmission-side user device and transfers the frame to a plurality of L2NWs to which the transmission-side accommodation SW is connected. When receiving a frame from any one of the plurality of L2NWs to which a reception-side accommodation SW is connected, the reception-side accommodation SW transfers, to a reception-side user device, only a frame from one L2NW allowed to transfer a frame to an access accommodation port and discards frames from the other L2NWs. At a switching time of the L2NWs, the reception-side accommodation SW changes the L2NW allowed to transmit a frame to the access accommodation port.

Abstract: An object of the present disclosure is to reduce band compression even in a case where a frame addressed to an original (overwritten) MAC is received again after a MAC address is overwritten. A communication device according to the present disclosure measures a traffic amount in any predetermined determination data unit, holds MAC entry information including the measured traffic amount and a MAC address in a MAC learning data holding unit, at the time when the number of pieces of MAC entry information held by the MAC learning data holding unit reaches an upper limit, searches for minimum MAC entry information with a minimum traffic amount from among traffic data amounts in determination data unit held by the MAC learning data holding unit, and overwrites the minimum MAC entry information obtained by search with unlearned MAC entry information that is not held by the MAC learning data holding unit.

Abstract: The disclosure has an object to allow local expansion without causing any loop. The disclosure is a system to which two nodes respectively belonging to different ring networks are connected, wherein the two nodes are connected to each other using a predetermined customized port, upon receipt of a predetermined unicast frame, one of the two nodes transmits the frame to another of the two nodes using the customized port, upon receipt of the predetermined unicast frame from the customized port, the other of the two nodes forwards the unicast frame, and upon receipt of a frame different from the predetermined unicast frame from the customized port, the other of the two nodes discards the frame.

Abstract: An object of the present disclosure is to provide a communication system, a communication path switching method, a communication device, and a program capable of continuing communication or shortening a communication disconnection time even during an operation of switching paths. A communication system according to the present disclosure is a communication system including two communication devices forming a duplex path with a common access network.

Abstract: An object is to provide a route switching method, a transfer device, and communication system that can continue communication even during route switching work. In a route switching method according to the present invention, in bypass transfer that transfers a packet while bypassing a non-transferable route, the transfer device having detected the non-transferable route attaches a bypass packet flag to the packet that passes through a non-transferable route and specifies the packet as a bypass packet, the transfer device having detected the non-transferable route returns the bypass packet and transfers the bypass packet in a direction opposite to that of the packet in the ring network, and the transfer device for which the blocked port is set in the ring network transfers the bypass packet through the blocked port before the route switching work.

Abstract: An object is to provide a monitoring device capable of acquiring ONU-specific information and connection information even in the case of an optical communication system with the MC system, and enabling optical fiber cable switching work to be finished in a short time. The monitoring device according to the present invention is a monitoring device that monitors an optical communication system in which an OLT and an ONU are connected by a communication optical fiber, and includes: an optical receiver for receiving a signal beam transmitted by the ONU from the communication optical fiber; and an OAM frame analysis unit for extracting, from the signal beam received by the optical receiver, an OAM frame at a MEG level at which the ONU and the OLT are set as monitoring end points, and acquiring a transmission source address and a MEG-ID that identifies a MEG in the OAM frame.

Abstract: With a network design apparatus, a network design method, and a network design processing program, a network configuration is designed for a network in which a transfer apparatus is disposed at each of a plurality of communication hubs and the communication hubs are connected via a link by a link portion apparatus in the transfer apparatus. In design of a network configuration, a threshold value of an inter-end delay and the number of redundant paths are calculated for each line on the basis of topology information, line information, and design parameter information. A path candidate set is calculated for each line on the basis of the threshold value of the inter-end delay and the number of redundant paths.

Abstract: A network design apparatus, a network design method, and a network design processing program design a network configuration for a network in which a transfer apparatus is disposed at each of a plurality of communication hubs, and the communication hubs are connected via a link by a link portion apparatus in the transfer apparatus. In design of the network configuration, the optimal path candidates of each of the lines minimizing a total cost value in the overall network is calculated. In the calculation of the optimal path candidates of each of the lines, only a path candidate of each of the lines can be selected, and a combination candidate of link portion apparatuses for each of the links is derived uniquely from the selected path candidate of each of the lines.

Abstract: With a network design apparatus, a network design method, and a network design processing program, a network configuration is designed for a network in which a transfer apparatus is disposed at each of a plurality of communication hubs and the communication hubs are connected via a link by a link portion apparatus in the transfer apparatus. In design of a network configuration, an optimal combination candidate of a link portion apparatus for each link for minimizing a total cost value in an overall network is calculated on the basis of a combination candidate set of link portion apparatuses. The combination candidate set of the link portion apparatuses is configured using only combination candidates with a cost-effectiveness indicating a ratio of a total capacity to a total cost value of the link portion apparatus higher than a predetermined reference.

Abstract: An object is to provide a monitoring device capable of acquiring ONU-specific information and connection information even in the case of an optical communication system with the MC system, and enabling optical fiber cable switching work to be finished in a short time. The monitoring device according to the present invention is a monitoring device that monitors an optical communication system in which an OLT and an ONU are connected by a communication optical fiber, and includes: an optical receiver for receiving a signal beam transmitted by the ONU from the communication optical fiber; and an OAM frame analysis unit for extracting, from the signal beam received by the optical receiver, an OAM frame at a MEG level at which the ONU and the OLT are set as monitoring end points, and acquiring a transmission source address and a MEG-ID that identifies a MEG in the OAM frame.

Abstract: With a network design apparatus, a network design method, and a network design processing program, a network configuration is designed for a network in which a transfer apparatus is disposed at each of a plurality of communication hubs and the communication hubs are connected via a link by a link portion apparatus in the transfer apparatus. In design of a network configuration, an optimal combination candidate of a link portion apparatus for each link for minimizing a total cost value in an overall network is calculated on the basis of a combination candidate set of link portion apparatuses. The combination candidate set of the link portion apparatuses is configured using only combination candidates with a cost-effectiveness indicating a ratio of a total capacity to a total cost value of the link portion apparatus higher than a predetermined reference.

Abstract: With a network design apparatus, a network design method, and a network design processing program, a network configuration is designed for a network in which a transfer apparatus is disposed at each of a plurality of communication hubs and the communication hubs are connected via a link by a link portion apparatus in the transfer apparatus. In design of a network configuration, a threshold value of an inter-end delay and the number of redundant paths are calculated for each line on the basis of topology information, line information, and design parameter information. A path candidate set is calculated for each line on the basis of the threshold value of the inter-end delay and the number of redundant paths.

Abstract: A network design apparatus, a network design method, and a network design processing program design a network configuration for a network in which a transfer apparatus is disposed at each of a plurality of communication hubs, and the communication hubs are connected via a link by a link portion apparatus in the transfer apparatus. In design of the network configuration, the optimal path candidates of each of the lines minimizing a total cost value in the overall network is calculated. In the calculation of the optimal path candidates of each of the lines, only a path candidate of each of the lines can be selected, and a combination candidate of link portion apparatuses for each of the links is derived uniquely from the selected path candidate of each of the lines.

Abstract: With a network design apparatus, a network design method, and a network design processing program, a network configuration is designed for a network in which a transfer apparatus is disposed for each of a plurality of communication hubs and the communication hubs are connected via a link by a link portion apparatus in the transfer apparatus. In design of a network configuration, a maximum total capacity of a link portion apparatus is calculated, and a combination candidate set of the link portion apparatus including only combination candidates of which a total capacity is equal to or smaller than the maximum total capacity is calculated.

Abstract: With a network design apparatus, a network design method, and a network design processing program, a network configuration is designed for a network in which a transfer apparatus is disposed for each of a plurality of communication hubs and the communication hubs are connected via a link by a link portion apparatus in the transfer apparatus. In design of a network configuration, an optimal path candidate of each of the lines, an optimal link portion apparatus combination candidate of each link, and an optimal transfer apparatus combination candidate at each of the communication hubs minimizing a total cost value in an overall network are calculated on the basis of a path candidate set, an interface combination candidate set, and a combination candidate set of a transfer apparatus.

Abstract: In the present invention, the extremely complicated setting and control and an extremely expensive optical component (wavelength locker) are not required, and optical output wavelength and optical output power can simply be set and controlled at a moderate price. At least one value for determining a dependence of the optical output wavelength on drive current and device temperature and at least one value for determining a dependence of the optical output power on drive current and device temperature in a light emitting device constituting first means 1 for emitting light are stored in fourth means 4.

Abstract: In the present invention, the extremely complicated setting and control and an extremely expensive optical component (wavelength locker) are not required, and optical output wavelength and optical output power can simply be set and controlled at a moderate price. At least one value for determining a dependence of the optical output wavelength on drive current and device temperature and at least one value for determining a dependence of the optical output power on drive current and device temperature in a light emitting device constituting first means 1 for emitting light are stored in fourth means 4.

Abstract: 1. The time of the sunrise 2. The time of the sunset 3. The time of the southing 4. The altitude in case of the southing (1) It understands a way of moving the day in the sun from 1, 2, 3, 4 above. (2) To decide the time to set and the position to set is made from (1) above. (3) The control board of “Solar-system Movable Mount” controls two mobiles of the turning-over part and the elastic part. It creates the agenda which controls the mobile of two pieces of the above based on the material which is (2). (4) The power of the control board uses the special solar cell of the control board. (5) When the above-mentioned solar cell doesn't generate electricity, the above-mentioned control board doesn't operate. Therefore, two mobiles of the above doesn't move.