JP2014179754A - Node device, optical network system, and fault recovery control method in node device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently suppress power consumption of an optical transmitter receiver group at standby while achieving reliability required for an optical network system.SOLUTION: A node device 20 comprises: a plurality of optical transmitter-receivers 21 and 21'; a transmitter-receiver aggregation device 22 managing states of the plurality of optical transmitter-receivers 21 and 21', and connecting the transmitter-receivers 21 in an operation state with an optical fiber 30; priority determination means 23 for determining the priority; operation information output means 24 for counting the number of routes for each of optical fibers 30 connected with the optical transmitter-receivers 21, and outputting the maximum value as a setting number M; and mode setting means 25 for selecting M optical transmitter-receivers from the optical transmitter-receivers 21' in a standby state in order of priority, and setting the selected optical transmitter-receivers to a high-speed start standby mode. When failures occur on the route, the optical transmitter-receiver aggregation device 22 changes the optical transmitter-receivers 21 to which the route where the failures occur is set from the operation state to the standby state, and selects and starts the optical transmitter-receivers 21' in the standby state in order of priority.

Description

  The present invention relates to a power saving node device of an optical network system having a redundant configuration.

In a metro / core optical wavelength division multiplexing network that handles large volumes of traffic, it is important to achieve high network reliability. The transmission capacity is increasing in each optical path constituting the optical communication network, and the communication interruption due to the occurrence of a failure has a large amount of data to be lost and greatly affects the service. Therefore, it is necessary to prepare a spare optical path redundantly with respect to the working optical path. Here, the optical path is a path in which one optical transceiver is disposed in each of two different optical nodes and optical communication is performed between the optical transceivers.
In a metro / core optical network, it is necessary to reliably and quickly recover from a failure in the event of a single failure of a link such as an optical fiber cut or a failure of an optical component such as an optical transceiver. For this reason, it is necessary to prepare as many spare optical paths as the working optical paths. The relationship between the working optical path and the backup optical path is such that 1 + 1 protection is performed for both communication and 1: 1 protection for selecting the working optical path and the standby optical path according to the communication status in order to recover the failure at high speed. Is used. The 1: 1 protection is disclosed in Patent Document 1, for example. In addition, as one of techniques for recovering from a failure at high speed in a metro / core optical network, Non-Patent Document 1 discloses a plurality of optical transceivers and optical fibers that are free of restrictions using an optical transceiver aggregation device. Has been disclosed.

JP 2002-190818 A

“Silicon Photonics Based Transponder Aggregator for Next Generation ROADM Systems”, Kanno et al., ECOC2012, Tu..3.A.5

  However, optical transceivers used in metro / core use many components that cannot be started at high speed. When these components are maintained in a state where they can be activated at high speed, power consumption during standby is increased.

  The present invention has been made in view of the above-described problems, and can sufficiently suppress the power consumption of the optical transceiver group during standby while realizing the reliability required for the optical network system. An object is to provide a node device, an optical network system, and a failure recovery control method in the node device.

  In order to achieve the above object, a node device according to the present invention is a node device that communicates with a plurality of node devices via an optical fiber using a set route, and is in a standby state when activated. Optical transceivers that are changed from the active state to the operating state, an optical transceiver aggregation device that manages the states of the multiple optical transceivers and connects the active optical transceivers to the optical fiber, and an optical transceiver in the standby state For each optical fiber connected to the priority determination means for determining the priority and the optical transceiver in operation, the number of set routes is counted, and the maximum value among them is output as the set number M Mode setting that selects M units in order of priority from the operating information output means to perform and the standby optical transceiver, and sets the fast startup standby mode in which the startup time from the standby state is shorter than the permissible time of communication interruption Means That. When a failure occurs on the path of the node device, the optical transmitter / receiver aggregation device changes the optical transmitter / receiver on which the failed route is set from the operating state to the standby state, The transmitter / receiver is selected and activated in order of priority.

  In order to achieve the above object, in the optical network system according to the present invention, a plurality of the node devices are connected to each other by optical fibers.

  In order to achieve the above object, a failure recovery control method in a node device according to the present invention is a failure recovery control method in a node device that communicates with a plurality of node devices through an optical fiber using a set route. The node device manages a plurality of optical transceivers that are changed from a standby state to an operating state by being activated, and the states of the plurality of optical transceivers. An optical transmitter / receiver aggregation device to be connected, and determines the priority of the standby optical transmitter / receiver, and counts the number of routes set for each optical fiber connected to the active optical transmitter / receiver. Then, the maximum value among them is output as the set number M, M units are selected in order of priority from the optical transceivers in the standby state, and the startup time from the standby state is shorter than the allowable time for the communication interruption time. Startup standby mode When a failure occurs on the route, the optical transceiver that is set up on the failed route is changed from the operating state to the standby state using the optical transmitter / receiver aggregation device, and the standby light Select and activate the transceivers in order of priority.

  According to the aspect of the present invention described above, the power consumption of the optical transceiver group during standby can be sufficiently suppressed while realizing the reliability required for the optical network system.

1A is a system configuration diagram of an optical network system 10 and FIG. 1B is a block configuration diagram of a node device 20 according to the first embodiment. It is a system configuration figure of optical network system 100 concerning a 2nd embodiment. It is a block block diagram of the node apparatus 200-6 which concerns on 2nd Embodiment. It is a figure which shows an example of the connection state of the optical transmitter-receivers 221-228 and optical fiber 300-5, 8, 9 of the node apparatus 200-6 which concerns on 2nd Embodiment. It is a figure which shows an example of the working light path information table 241 which concerns on 2nd Embodiment. It is a figure which shows an example of the backup optical transmitter-receiver management table 253 which concerns on 2nd Embodiment. In the optical network system 100 which concerns on 2nd Embodiment, it is a figure which shows the state of the network after switching. In the optical network system 100 which concerns on 2nd Embodiment, it is a figure which shows the connection state of the optical transmitter-receivers 221-228 after switching. It is a figure which shows the state which two failures generate | occur | produced in the optical network system 100 which concerns on 2nd Embodiment. It is a figure for demonstrating an example of the expansion method of a network. It is a figure which shows an example of the working light path information table 241B which concerns on 3rd Embodiment. It is a system configuration figure of optical network system 100C concerning a 4th embodiment. It is a figure which shows the connection state of optical transmitter-receiver 221C-2212C in the optical network system 100C which concerns on 4th Embodiment. It is a figure which shows an example of the working light path information table 241C which concerns on 4th Embodiment. It is a figure which shows an example of the backup optical transmitter-receiver management table 253C which concerns on 4th Embodiment.

(First embodiment)
An optical network system and a node device according to the first embodiment will be described. FIG. 1A shows a system configuration diagram of the optical network system according to the present embodiment, and FIG. 1B shows a block configuration diagram of the node device. In FIG. 1A, an optical network system 10 according to the present embodiment is configured by connecting a plurality of node devices 20 to each other through optical fibers 30. Two predetermined node devices 20 transmit and receive information between specific optical transceivers arranged in each node device 20 through a predetermined route. Hereinafter, this route is referred to as a route.

  In the present embodiment, the node device 20 that is shaded in FIG. 1A will be described. In the following description, a node device indicated by hatching is referred to as a node device 20, and node devices 20-1, 2,..., L (L is an integer of 1 or more) adjacent to the node device 20 and nodes not adjacent to the node device 20. The description will be made separately from the devices 20′-1, 2,. Similarly, an optical fiber connecting the node device 20 and the node devices 20-1, 2,..., L is described as an optical fiber 30-1, 2,. The optical fibers 30′-1, 2,.

  As shown in FIG. 1A, the node device 20 is adjacent to the L node devices 20-1, 2,..., L, and is connected by L optical fibers 30-1, 2,. Has been. As shown in FIG. 1B, the node device 20 according to the present embodiment includes a plurality of optical transceivers 21-1, 2,..., L, 21′-1, 2,. The apparatus 22 includes a priority determination unit 23, an operation information output unit 24, and a mode setting unit 25.

  The plurality of optical transceivers 21-1, 2,..., L, 21'-1, 2,. Here, the optical transceivers 21-1, 2,..., L are in an operating state, and the optical transceivers 21'-1, 2,.

  The optical transmitter / receiver aggregation device 22 manages the states of the plurality of optical transmitters / receivers 21-1, 2,..., L, 21'-1, 2,. In the configuration of FIG. 1A, the optical transceiver aggregation device 22 activates L optical transceivers 21-1, 2,..., L to change from a standby state to an operating state, and performs optical transmission / reception in the operating state. , L are connected to optical fibers 30-1, 2, ..., L, respectively. Thus, L optical transceivers 21-1, 2,..., L are connected to adjacent node devices 20-1, 2,..., L via optical fibers 30-1, 2,. Various information is transmitted / received between the optical transceivers arranged in the connected node devices. Note that the optical transceiver and the optical fiber are not necessarily connected one-to-one.

  The priority determination means 23 determines the priority of the optical transceivers 21'-1, 2,. In this embodiment, the priority determination means 23 determines the priority by checking the power consumption of the optical transceivers 21'-1, 2,... In the standby state and lowering the order of activation in ascending order of power consumption. Note that the priority determination method is not limited to this. For example, for an optical network system that is required to have high fault tolerance, for example, the priority is determined by increasing the priority in order of start-up time. You can also.

  The operation information output means 24 indicates the number of routes set for each of the optical fibers 30-1, 2,..., L connected to the optical transceivers 21-1, 2,. Count and output the maximum value among them as the set number M.

  The mode setting means 25 is the same as the set number M output from the operation information output means 24 in the priority order determined by the priority determination means 23 among the optical transceivers 21′-1, 2,... The optical transceiver 21 ′ is selected. The mode setting means 25 sets the high-speed startup standby mode in which the startup time from the standby state is shorter than the permissible time for the communication interruption time in the selected M optical transceivers 21 ′. Further, the mode setting means 25 according to the present embodiment, for the optical transceiver 21 ′ in the standby state in which the fast startup standby mode has not been set, has a startup time from the standby state that is longer than the startup time in the fast startup standby mode. A minimum power standby mode is set that is long and consumes less power than the fast startup standby mode. Here, the power consumption in the fast startup standby mode is larger than the power consumption in the minimum power standby mode, but by maintaining components that are not required for fast startup in the standby state, the power consumption in the active state is greater It is getting smaller.

  In the node device 20 configured as described above, when a failure occurs in the route, the optical transmitter / receiver aggregation device 22 changes the optical transmitter / receiver 21 in which the route in which the failure has occurred from the operating state to the standby state. And the connection with the optical fiber 30 is released, and the optical transceiver 21 ′ in the standby state is selected and activated in order of priority. Then, the optical transmitter / receiver aggregation device 22 connects the newly activated optical transmitter / receiver to the optical fiber related to the backup route of the route in which the failure has occurred, thereby causing a failure in the optical network system 10. Is restored.

  As described above, in the optical network system 10 according to the present embodiment, the node device 20 includes the optical fibers 30-1, 2,... Connected to the optical transceivers 21-1, 2,. For each L, the number of set routes is counted, and the fast start standby mode is set to M optical transceivers 21 ′ having the same number as the maximum value (set number M). That is, only the number of standby optical transceivers 21 ′ required for recovery from a failure that has occurred in one path is set to the fast startup standby mode. Then, when a failure occurs, the node device 20 can start up the optical transceiver 21 ′ set in the fast startup standby mode at high speed and restore the failure within the allowable time for the communication interruption time.

  The optical network system 10 and the node device 20 according to the present embodiment set only the number of optical transceivers 21 ′ necessary for recovery from a failure in the fast startup standby mode, thereby realizing high network reliability. The amount of power consumption related to the backup route can be minimized.

  The optical network system 10 and the node device 20 according to the present embodiment further set a power minimum standby mode in which the power consumption is further reduced in the standby optical transceiver 21 ′ having a lower priority than the M optical transceivers 21 ′. To do. Thereby, it is possible to further suppress the power consumption of the optical transceiver 21 ′ that is not used for recovery of a failure that has occurred in one path.

  Note that the node device 20 includes setting information holding means for holding setting information including at least information on a set route and a spare optical fiber for each optical fiber connected to the active optical transceiver. It is desirable to further provide. In this case, the operation information output unit 24 can easily count the number of routes with reference to the route setting information held in the setting information holding unit. Further, when a failure occurs, the optical transmitter / receiver aggregating apparatus 22 identifies the switching-destination optical fiber based on the spare optical fiber held in the setting information holding unit, and identifies the activated optical transceiver. It is possible to quickly connect to the previous optical fiber, and the time required for recovery can be further reduced.

(Second Embodiment)
A second embodiment will be described. FIG. 2 shows a system configuration diagram of the optical network system according to the present embodiment. In FIG. 2, the optical network system 100 according to the present embodiment is configured by connecting eight node devices 200 to each other through an optical fiber 300. 2 are merely examples, and the technical scope of the present invention is not limited to them. Also, devices and wiring not related to the failure recovery function are omitted.

  Hereinafter, although the description will focus on the node device 200-6, the other node devices 200 function in the same manner as the node device 200-6. In FIG. 2, the node device 200-6 is adjacent to three node devices 200-2, 5, and 7 and is connected to each other by optical fibers 300-5, 8, and 9. Note that the node device 200-6 is connected to a node device or the like (not shown) via the optical fibers 300-X, Y, and Z. However, the node device 200-6 is not directly related to the present embodiment, and thus illustration thereof is omitted.

  As indicated by a solid line in FIG. 2, in the node device 200-6, four routes 600-1, 2, 3, 4 used for communication with the node devices 200-4, 3, 7, 5 are set. ing. As shown by dotted lines in FIG. 2, spare routes 600B-1, 2, 3, and 4 are set for the working routes 600-1, 2, 3, and 4, respectively.

  In general network control, the transmission distance of each path is set to be the shortest, and optical paths that exit different optical fibers do not overlap with optical fibers between different node devices. Further, the spare route is set so as not to overlap with the route that is in operation. Therefore, even if one optical fiber is disconnected, the spare route and the working route are not cut simultaneously. Here, the standby route and the active route are set by the network control device 400 (not shown) according to the network status.

  A block diagram of the node device 200-6 is shown in FIG. In FIG. 3, a plurality of optical fibers 300, a network control device 400, and a client device 500 connected to the node device 200-6 are shown together. As illustrated in FIG. 3, the node device 200-6 according to this embodiment includes a node control unit 210, a plurality of optical transceivers 221, 222,..., Three optical transceiver aggregation devices 231, 232, 233, and an optical device. A path management unit 240 and a failure control unit 250 are provided.

  The node control unit 210 manages various types of information on the route in operation, and controls the optical transceivers 221, 222,... And the optical transceiver restriction devices 231, 232, 233, which are optical components in the node device 200-6. To do.

  The optical transceivers 221, 222,... Are power-saving optical transceivers. As a non-power-saving type optical transceiver, for example, the authors “Mizutani et al.“ Proposal for introducing a power-saving transponder having multiple standby modes into a backup path ”, IEICE Society Conference Proceedings B-12 -7, 2012 ”can be applied. When there is no need to distinguish between the optical transceivers, the plurality of optical transceivers 221, 222,... Are simply referred to as the optical transceiver 220. The optical transceiver 220 is set to any one of three operation modes: a normal operation mode, a fast startup standby mode, and a power minimum standby mode. The optical transceiver 220 is set to the normal operation mode during operation. Here, the power consumption in the normal operation mode is about 300 W. On the other hand, the optical transceiver 220 is set to either the fast start standby mode or the minimum power standby mode during standby. In this embodiment, the fast startup standby mode is a mode in which the power consumption reduction rate is as small as 23% (power consumption amount of about 231 W), but can be started up at a high speed of about 30 msec, and the minimum power standby mode is a power consumption reduction rate of 90%. (Power consumption is about 30 W), while the startup time is a slow mode of several hundreds msec.

  The optical transmitter / receiver aggregation devices 231, 232, and 233 manage the connection between the optical transmitter / receiver 220 and the optical fiber 300 in accordance with an instruction from the failure control unit 250. As the optical transceiver aggregation devices 231, 232, and 233, an optical transceiver aggregation device described in Non-Patent Document 1 and capable of high-speed switching can be applied. That is, the optical transmitter / receiver aggregation devices 231, 232, and 233 can switch paths in about 1 msec and can connect the optical transmitter / receiver 220 and the optical fiber 300 without restriction. In FIG. 3, nothing is arranged between the optical transceiver aggregation devices 231, 232, and 233 and the six optical fibers 300, but WXC (Wavelength Cross Connect) that can switch signals between the optical fibers. ) A device or the like can also be arranged.

  In this embodiment, the optical transmitter / receiver aggregation devices 231 and 232 manage the connection state between the optical transmitters / receivers 221-228 and the optical fibers 300-5, 8, and 9 shown in FIG. On the other hand, the optical transceiver aggregation device 233 manages the connection state between other optical transceivers and optical fibers 300-X, Y, and Z that are not shown in FIG. In the present embodiment, the operation of the optical transceiver aggregation devices 231 and 232 will be mainly described.

  FIG. 4 shows a connection state between the optical transceivers 221-228 and the optical fibers 300-5, 8, and 9 set by the optical transceiver aggregation devices 231 and 232 during normal operation. In FIG. 4, the optical transceiver in the normal operation mode is indicated by a solid line, the optical transceiver in the fast startup standby mode is indicated by a dotted line, and the optical transceiver in the minimum power standby mode is indicated by a one-dot chain line. As shown in FIG. 4, the optical transceivers 221 and 222 and the optical fiber 300-5 are connected, the optical transceiver 223 and the optical fiber 300-9 are connected, and the optical transceiver 224 and the optical fiber 300-8 are connected. ing.

  The optical path management unit 240 manages the connection state between the own device and the node devices 200-2, 9 and 5 adjacent to the own device by using the working optical path information table 241, and switches the switch when a failure occurs. Necessary information is extracted from the operating light path information table 241 and output to the failure control unit 250. The optical path management unit 240 according to the present embodiment registers the setting states of all the optical transceiver aggregation devices 231, 232, and 233 in the node device 200-6 in the working optical path information table 241. Information necessary for switching can be output to the failure control unit 250.

  Each time the path setting is changed, the optical path management unit 240 uses the optical fiber 300 that connects the own device and the node device 200 adjacent to the own device. The operating light path information table 241 is updated after confirming the number of paths. Thereby, information necessary for switching can be managed independently in the node device 200-6, and information can be provided to the failure control unit 250 at high speed even in a dynamically changed network.

  An example of the operating light path information table 241 is shown in FIG. In FIG. 5, the operating optical path information table 241 includes, for each optical fiber 300 connected to adjacent node devices, all the optical transceiver aggregation devices 231, 232, and 233 arranged in the node device 200-6. The number of active routes is registered in. That is, as shown in FIGS. 2 and 5, the optical transceiver aggregation devices 231 and 232 are connected to the optical fibers 300-5, 8, and 9, and in the optical fiber 300-5, two paths are connected to the optical fiber 300-. In each of 8 and 9, one route is set. On the other hand, for the optical fibers 300-X, Y, and Z omitted in FIG. 2, one, one, and zero paths are set, respectively.

  Here, since the optical transceiver aggregation devices 231 and 232 are connected to the same optical fiber 300, they are managed as one optical transceiver aggregation device in the operating optical path information table 241. By managing the optical transceiver aggregation devices connected to the same optical fiber 300 as the same one, the amount of information to be managed can be reduced, and the memory cost can be reduced and the associated control speed can be increased.

  The failure control unit 250 controls the optical transceiver aggregation devices 231, 232, and 233 based on the information input from the optical path management unit 240, and switches the connection between the optical transceiver 220 and the optical fiber 300. In FIG. 3, the failure control unit 250 includes a CPU 251, a mode switching unit 252, and a standby optical transceiver management table 253.

  The CPU 251 determines the set number M of optical transceivers to wait in the fast start standby mode from the standby optical transceivers 220 that are on standby. In the present embodiment, the CPU 251 sets the maximum number of operating routes registered in the operating light path information table 241 as the set number M. In the case of the working optical path information table 241 illustrated in FIG. 5, for the optical transceiver aggregation devices 231 and 232 managed as one optical transceiver aggregation device, the largest number of routes in the optical fiber 300-5. Is set, and the number thereof is “2”. In this case, the CPU 251 sets “2” as the setting number M for the optical transceiver aggregation devices 231 and 232. Similarly, the CPU 251 sets “1” to the set number M for the optical transceiver aggregation device 233.

  The mode switching unit 252 sets the optical transceivers 220 for the set number M determined by the CPU 251 in the fast startup standby mode in the order of priority registered in the standby optical transceiver management table 253. Here, setting information of all the optical transceivers 220 arranged in the node device 200-6 is registered in the backup optical transceiver management table 253. FIG. 6 shows an excerpt of various types of information of the optical transceiver 220 managed by the optical transceiver aggregation devices 231 and 232 from the standby optical transceiver management table 253. In the standby optical transmitter / receiver management table 253 in FIG. 6, the operation mode, the priority, and the like are registered for the optical transmitters / receivers 221 to 228 managed by the optical transmitter / receiver aggregation devices 231 and 232. In FIG. 6, the route setting information of the active optical transceivers 221-224 is also shown, but since the information is also managed by the node control unit 210, the information is not necessarily stored in the standby optical transceiver management table 253. There is no need to register.

  In the node device 200-6 configured as described above, the mode switching unit 252 determines that each of the mode switching units 252 is based on the setting number M determined by the CPU 251 and the priority registered in the standby optical transceiver management table 253. A procedure for determining the operation mode of the optical transceiver 220 will be described. As described above, the CPU 251 sets “2” as the setting number M of the optical transceiver aggregation devices 231 and 232. On the other hand, in FIG. 6, in the eight optical transceivers 221-228 managed by the optical transceiver aggregation devices 231 and 232, the optical transceivers 221-224 are operating and the optical transceivers 225-228 are on standby. It is in.

  In this case, the mode switching unit 252 includes two optical transceivers 225 and 226 in descending order of priority based on the set number M “2” set by the CPU 251 from the optical transceivers 225 to 228 that are not operating. Select to set the fast startup standby mode. Further, the mode switching unit 252 sets a power minimum standby mode with a small amount of power consumption to the remaining optical transceivers 227 and 228 in standby. The mode switching unit 252 registers the priority for the standby optical transceiver 220 in the standby optical transceiver management table 253, so that the switching destination optical transceiver can be determined at a high speed when a failure occurs. it can.

  As described above, in the node device 200-6 according to the present embodiment, the set number M of the optical transceivers waiting in the fast startup standby mode is used using the optical fiber connected to the optical transceiver of the own device. By matching the maximum number of active routes, the minimum required number of optical transceivers can be made to stand by in the fast start-up standby mode for a single failure, and the failure can be recovered quickly. Can do. This is because the path is set to have the shortest distance, so that the optical path from one optical fiber of the optical transceiver aggregation devices 231 and 232 joins the optical path from another optical fiber. Because there is nothing to do.

  Furthermore, the node device 200-6 according to the present embodiment can further reduce power consumption by causing the remaining standby optical transceivers with lower priority to stand by in a power minimum standby mode with lower power consumption. it can. In the node device 200-6 according to the present embodiment, the power consumption of the standby optical transceivers 225 to 228 managed by the optical transceiver aggregation devices 231 and 232 is the consumption of the active optical transceivers 221-224. The power consumption was about 522 W (231 W × 2 units + 30 W × 2 units) compared to about 1200 W (300 W × 4 units), and the power consumption could be reduced to 43.5%.

  Next, an operation procedure when a failure occurs in the node device 200-6 according to the present embodiment will be described. Hereinafter, a case where a failure occurs in the optical fiber 300-2 in the optical network 100 shown in FIG. 2 will be described.

  When the optical fiber 300-2 is disconnected, the communication of the routes 600-1 and 600-2 using the optical fiber 300-2 is disconnected. When the communication is disconnected, the node control unit 210 of the node device 200-6 detects that a failure has occurred. The node control unit 210 notifies the failure control unit 250 that a failure has occurred in the routes 600-1 and 600-2.

  When the failure control unit 250 is notified of the failure information (routes 600-1 and 2 are disconnected) from the node control unit 210, the failure control unit 250 refers to the backup optical transceiver management table 253 shown in FIG. The transceiver 220 is activated. In this embodiment, since the failure control unit 250 has a failure in the routes 600-1 and 600-2, the backup optical transceiver 225 in which a backup route for these routes is set. The two spare optical transceivers 225 and 226 are selected from the highest priority in the order of priority, and activated.

  Here, since the two standby optical transceivers 225 and 226 are set in the fast start standby mode for the optical transceiver aggregation devices 231 and 232 in advance, the failure control unit 250 causes the optical transceiver 225 to operate. By selecting and starting 226, the optical transceivers 225 and 226 are started at a high speed of about 30 msec.

  In parallel with the activation of the optical transceivers 225 and 226 according to the priority, the failure control unit 250 cooperates with the node control unit 210 to switch the client apparatus 400 to the standby system and the optical transceiver aggregation apparatus 231, 232 is switched.

  The optical transmitter / receiver aggregation devices 231 and 232 follow the instructions of the node control unit 210 and the failure control unit 250, based on the standby optical transmitter / receiver management table 253 shown in FIG. The path of “optical transceiver 221-optical fiber 300-5” is closed and the path of “optical transceiver 225-optical fiber 300-9” is newly set. Further, the optical transmitter / receiver aggregation devices 231 and 232 close the path of “optical transmitter / receiver 222-optical fiber 300-5” for the path 600-2 where the failure has occurred, and “optical transmitter / receiver 226-optical fiber 300-”. A new route 9 ″ is set. As a result, communication between the node devices 200-4 and 3 using the backup routes 600B-1 and 2 in FIG. 2 is started.

  Note that both the switching of the client device 400 and the switching of the optical transmitter / receiver aggregation devices 231 and 232 can operate in several milliseconds, so that the failure can be recovered only by the time for starting the optical transmitters / receivers 225 and 226. it can. FIG. 7 shows the state of the network after switching between the optical transceiver 220 and the optical fiber 300.

  The node device 200-6 according to the present embodiment further updates various information on the active route held in the node control unit 210 to the latest information after switching the optical transceiver 220 and the optical fiber 300. At the same time, the contents of the working optical path information table 241 and the backup optical transceiver management table 253 are updated to the latest contents. Thereafter, the node device 200-6 resets the operation mode of the optical transceiver 220.

  For example, in the case of the network state after switching shown in FIG. 7, since the three most frequently used operating paths are set in the optical fiber 300-9, the CPU 251 sets “3” as the setting number M. . Then, the mode switching unit 252 selects the optical transceivers 221, 222, 227 in descending order of priority from the waiting optical transceivers 221, 222, 227, 228 according to the determined setting number M “3”. The fast start standby mode is set, and the minimum power standby mode is set for the remaining optical transceivers 228. FIG. 8 shows a connection state between the optical transceivers 221-228 and the optical fibers 300-5, 8, and 9 after the resetting.

  In FIG. 8, the optical transceiver in the normal operation mode is indicated by a solid line, the optical transceiver in the fast start standby mode is indicated by a dotted line, and the optical transceiver in the minimum power standby mode is indicated by a one-dot chain line. As shown in FIG. 8, the optical transceivers 223, 225, 226 and the optical fiber 300-9 are connected, and the optical transceiver 224 and the optical fiber 300-8 are connected. By resetting the standby mode of the standby optical transmitter / receiver 220, the network after the failure can recover from the failure at a high speed with respect to a part of the failure, and can have high failure tolerance.

  Here, in the optical network system 100 shown in FIG. 2, a case where a failure occurs in the optical fiber 300-8 following the failure in the optical fiber 300-2 will be described. The state of the optical network system 100 in this case is shown in FIG.

  As shown in FIG. 9, when disconnection or the like occurs in the optical fiber 300-8 subsequent to the optical fiber 300-2, and the communication of the route 600-4 in operation is cut, the node device 200-6 The fault control unit 250 further activates the optical transceiver 227 that is standby in the minimum power standby mode and has the third priority in the standby optical transceiver management table 253 of FIG. Then, the optical transmitter / receiver aggregation devices 231 and 232 refer to the standby optical transmitter / receiver management table 253 shown in FIG. "" Is closed and the path "optical transceiver 227-optical fiber 300-5" is newly set.

  Although it takes some time to start up the optical transceiver 227, a route using the optical transceiver 227 is opened after several hundred msec, and communication via the path 600B-4 in FIG. 2 is started. Therefore, the optical network system 100 according to the present embodiment has high fault tolerance against multiple faults.

  As described above, the node device 200-6 according to the present embodiment has a spare optical transceiver corresponding to the largest number of operating routes among the optical fibers 300 connecting the adjacent node devices 200. 220 is set to the fast startup standby mode. As a result, when a single failure occurs, the optical transceiver 220 standing by in the fast startup standby mode can be started reliably and quickly, and the failure can be recovered at high speed. On the other hand, the remaining standby optical transceivers 220 can be further reduced in power consumption by setting a power minimum standby mode with low power consumption.

  Here, in this embodiment, the optical path management unit 240 is arranged in the node device 200-6, and the optical path management unit 240 is started from the network control device 400 that regularly controls the node control unit 210 and the entire network. The configuration is such that the set state of the road is acquired and the operating light path information table 241 is updated. When obtaining necessary information from the network control device 400 when a failure occurs, the network control device 400 is arranged at a different location from the node device 200, and therefore, a transmission delay of several milliseconds to several tens of milliseconds due to signal exchange or the like. Occurs. On the other hand, by always holding the latest information in the operating light path information table 241, when the failure occurs, the working light path information table 241 can be referred to restore the failure at an early stage.

  In this embodiment, the failure control unit 250 is arranged in the node device 200-6 to control the operation mode of the standby optical transceiver 220. When the operation mode of the spare optical transceiver 220 is controlled in the network control apparatus 400 that controls the entire network, a plurality of spare optical transceivers 220 that are in standby in the fast startup standby mode are shared by a plurality of routes. It is necessary to manage a very large number of optical transceivers 220 arranged in the node device 200. For this purpose, it is necessary to disperse and arrange the network control devices 400 at appropriate node intervals and to arrange distributed control for linking the network control devices. However, the amount of information that can be handled by the distributed control is limited, and it is difficult to manage many standby optical transceivers 220 to the standby operation mode.

  On the other hand, when the failure control unit 250 is arranged in the node device 200-6 to control the operation mode of the standby optical transceiver 220 for each node device 200, the backup route is not applied to the network control. Efficient power-saving standby control can be realized. This can coexist with the existing distributed network control, and can also coexist with the centralized control network control that makes it easy to dynamically construct a new network.

(Third embodiment)
A third embodiment will be described. The node device according to the present embodiment is configured in the same manner as the node device 200-6 of FIG. 3 described in the second embodiment. Hereinafter, in this embodiment, “B” is given to the reference numerals of the elements corresponding to the elements of the optical network 100 shown in FIG. 2 and the node device 200-6 shown in FIG. 3 of the second embodiment. . Hereinafter, a description will be given centering on differences from the second embodiment.

  In a general optical network system, a new route is added at any time as the traffic increases (network expansion). For example, as shown in FIG. 10A, this network is expanded by adding a route 620B-1 ′ having the same route as the route 610B-1 in operation, and operating in the added route 620B-1 ′. This is performed by using an optical signal having a wavelength λ2 different from the wavelength λ1 of the optical signal used in the middle route.

  On the other hand, as shown in FIG. 10 (b), when a wavelength λ2 is already used in another path 600B-X in some optical fibers in the operating path when adding a path, The route of the same route as the route 610B-1 in operation cannot be set. In this case, as shown in FIG. 10C, a route in which a part of the route is changed is set as a route 620B-1 to be added.

  When two routes 610B-1 and 620B-1 in which a part of the route is changed are set between the node devices 200B-6 and 4, depending on the position where the failure occurs, the second embodiment may be used. In the node device 200-6 described, the required number of optical transceivers 220 cannot be set to the fast startup standby mode. That is, when the optical path management unit 240 manages only the optical fiber 300 connected to the optical transceiver in its own apparatus, the optical fiber that is not connected to the optical transceiver and is shared by the two paths. When a failure occurs at 300, only one of the two routes can be handled.

  Therefore, in the present embodiment, the optical path management unit 240B obtains the setting information of the operating route for all the optical fibers 300B used in the route from the network control device 400B, and for every optical fiber 300B. The number of working routes is counted and registered in the working light path information table 241B. FIG. 11 shows an example of the operating optical path information table 241B in the optical network system 100B shown in FIG. In the case of the working optical path information table 241B illustrated in FIG. 11, the optical path management unit 240B sets the setting number M for the optical transceiver aggregation apparatuses 231B and 232B to “2”. Then, the failure control unit 250B determines two optical transceivers 220B to be set in the fast startup standby mode according to the priorities registered in the working optical path information table 241B and the standby optical transceiver management table 253B (not shown).

  By setting the maximum value of the number of operating paths of all optical fibers 300B used in the operating path as the number of optical transceivers 220B set in the fast startup standby mode, the optical transceivers are connected to the optical transceivers. Even when a failure occurs in the optical fiber 300 that is not shared and shared by two routes, it is possible to reset different backup routes for the shared route.

  As described above, according to the present embodiment, in the optical network 100B constructed by two routes sharing a part of the two routes as traffic increases, a plurality of routes are caused by a single failure of the optical fiber 300B. Even when a failure occurs, the minimum number of optical transceivers 220B necessary for high-speed recovery can be set in the high-speed startup standby mode. Then, by setting the standby optical transceiver 220B other than the fast start standby mode to the power saving standby mode, the power consumption can be suppressed to the minimum necessary.

(Fourth embodiment)
A fourth embodiment will be described. FIG. 12 shows a system configuration diagram of the optical network system according to the present embodiment. In FIG. 12, an optical network system 100C according to the present embodiment is configured in the same manner as the optical network system 100 of FIG. 2 described in the second embodiment. The node device according to the present embodiment is configured in the same manner as the node device 200-6 of FIG. 3 described in the second embodiment. Hereinafter, in the present embodiment, description will be given by adding “C” to the reference numerals of elements corresponding to the elements of the optical network 100 illustrated in FIG. 2 and the node device 200-6 illustrated in FIG. . Hereinafter, a description will be given centering on differences from the second embodiment.

  In FIG. 12, the node device 200C-6 is adjacent to three node devices 200C-2, 5, and 7, and is connected to each other by optical fibers 300C-5, 8, 310C-9, and 320C-9. The optical fiber 310C-9 and the optical fiber 320C-9 are geographically arranged in the same direction and wired together. In the present embodiment, these two optical fibers are defined as one optical fiber group 300C′-9. deal with. FIG. 13 shows a connection state between the optical transceivers 221C-2212C whose connection destinations are set by the optical transceiver aggregation apparatuses 231C and 232C and the optical fiber groups 300C′-5, 8, and 9. Also in FIG. 13, the optical transceiver in the normal operation mode is indicated by a solid line, the optical transceiver in the fast startup standby mode is indicated by a dotted line, and the optical transceiver in the minimum power standby mode is indicated by a one-dot chain line.

  In the present embodiment, as shown in FIG. 12, six paths 600C-1, 2, 4, 5, 610C-3, and 620C-3 are set in the node device 200C-6. Here, in the routes 600C-2, 4, 610C-3, and 620C-3, an optical signal having a wavelength λ1 is used for communication. On the other hand, in the routes 600C-1 and 5, an optical signal having a wavelength λ2 is used for communication. As described above, in one optical fiber 300C, optical signals with different wavelengths are set for different optical paths.

  Then, the optical path management unit 240C operates for each wavelength used for the optical fiber groups 300C′-9, 5, and 8 connected to the adjacent node devices 200C-7, 2, and 5. Are registered in the working optical path information table 241C. An example of the operating light path information table 241C in the case of FIG. 12 is shown in FIG. In FIG. 14, the optical fiber group 300C′-9 uses the optical signal having the wavelength λ1 for each of the two optical fibers 310C-9 and 320C-9. Therefore, the number of operating paths having the wavelength λ1 is two. Become. Also, since one optical signal of wavelength λ1 and wavelength λ2 is used in each of the optical fiber groups 300C′-5 and 8, operating paths of wavelengths λ1 and λ2 in the optical fiber groups 300C′-5 and 8 are used. Each number is 1.

  Then, the optical path management unit 240C extracts the maximum number of operating routes for each wavelength λ using the operating optical path information table 241C of FIG. 14 and sets the total value as the set number M. That is, in the case of the operating optical path information table 241C shown in FIG. 14, in the optical transceiver aggregation devices 231C and 232C, the maximum number of operating routes for wavelength λ1 is 2, the maximum number of operating routes for wavelength λ2 is 1, and the wavelength λ3. Since the maximum number of operating routes is 0, the optical path management unit 240C sets the total value “3” as the set number M of the optical transceiver aggregation devices 231C and 232C.

  Then, the failure control unit 250C according to the present embodiment performs backup optical transmission / reception based on the setting number M calculated by the optical path management unit 240C and the priority of the backup optical transceiver management table 253C illustrated in FIG. The M units of the container 220C are set to the fast start standby mode. That is, the failure control unit 250C refers to the priority of the backup optical transmitter / receiver management table 253C illustrated in FIG. 15 and selects the three optical transmitters / receivers 227C, 228C, and 229C in descending order of priority for each wavelength. Set to fast startup standby mode. Thereby, even when a failure occurs in the optical fiber 300C disposed between the node devices due to a disaster that occurs between the node devices, the failure can be recovered at high speed.

  The fault control unit 250C according to the present embodiment further sets the minimum power standby mode for the remaining optical transceiver 220C that is on standby, and registers these settings in the standby optical transceiver management table 253C.

  In the standby optical transceiver management table 253C shown in FIG. 15, two optical transceivers 227C and 228C stand by in the fast startup standby mode for the wavelength λ1, and one optical transceiver 229C fast for the wavelength λ2. Waiting in startup standby mode.

  Then, when a failure occurs in the route, the node device 200C-6 according to the present embodiment selects and activates the optical transceiver 220C that is set to the same wavelength as the route in which the failure has occurred in descending order of priority. Thus, the failure can be recovered at a high speed. Since the operation after selecting the optical transceiver 220C is the same as the operation of the node device 200-6 described in the second embodiment, detailed description thereof is omitted.

  As described above, the node device 200C-6 according to the present embodiment uses the operating optical path information table 241C illustrated in FIG. 14 to determine the number of operating paths for each wavelength λ for the related optical fiber group 300 ′. And the total value of the maximum number of routes counted for each wavelength λ is set as the set number M. In this case, the minimum number of optical transceivers 220C required to stand by in the fast start standby mode necessary for recovery from a single failure of the optical fiber group can be put on standby in the fast start standby mode.

  Then, by setting the power minimum standby mode for the remaining optical transceivers 2210C, 2211C, and 2212C, the power consumption of the spare optical transceivers 227C-2212C is approximately 783 (231W × 3 + 30W × 3). The power consumption can be reduced to 43.5% with respect to the power consumption 1800W (300W × 6 units) of the optical transceivers 221C-226C for the operation route.

  Here, in this embodiment, the used wavelength information of the operating route is used, but the same effect can be obtained even if the wavelength information of the backup route is used. In addition, a new route using a different wavelength can be newly established in the operating route. In this case, an operating optical transceiver can be used, and it is not necessary to newly start the optical transceiver, so that quick recovery can be realized. In addition, when a failure is recovered by using an operating optical transceiver at a different wavelength, switching on the client device 500C side is not required, and the recovery time between the client devices 500C can be increased. In this case, for example, the failure can be recovered within 20 msec, which is the continuity recovery time for high-speed activation between the optical transceivers.

  Even when a failure occurs in the optical transceiver 220C instead of the optical fiber group 300 ', the failure can be quickly recovered by using the optical transceiver that stands by in the fast startup standby mode. Even when a failure occurs in the optical transceiver 220C, there is always an optical transceiver 220C that is set to the same wavelength as the setting wavelength of the standby path, so it is necessary to change the wavelength of the optical transceiver 220C when the failure is recovered. Therefore, the failure can be recovered at a higher speed than the node device 200-6 described in the second embodiment.

  Here, the fact that there is no need to change the wavelength of the optical transceiver 220C at the time of fault recovery means that a light source with a slow wavelength variable speed can be used in the optical network system 100C, and the fault tolerance is high without being limited to the type of laser. Can be constructed. In particular, in an optical transceiver using a digital coherent technology capable of future large-capacity communication, a light source with low linewidth noise is desirable, and an external resonator type tunable laser is used. In general, a wavelength tunable laser of an external cavity type is slow. Even when such a laser is used, high-speed failure recovery can be realized.

  The present invention can be applied not only to communication networks for cores and metros but also to all communication networks using light. Furthermore, the invention of the present application is not limited to the above-described embodiment, and any design change or the like within a range not departing from the gist of the invention is included in the invention.

DESCRIPTION OF SYMBOLS 10 Optical network system 20 Node apparatus 21, 21 'Optical transmitter-receiver 22 Optical transmitter-receiver aggregation apparatus 23 Priority determination means 24 Operation information output means 25 Mode setting means 30 Optical fiber 100 Optical network system 200 Node apparatus 210 Node control part 220 Light Transmitter / receiver 231, 232, 233 Optical transmitter / receiver aggregation device 240 Optical path management unit 241 Operating optical path information table 250 Fault control unit 251 CPU
252 Mode switching unit 253 Standby optical transceiver management table 300 Optical fiber 400 Network control device 500 Client device

Claims (10)

In a node device that communicates with a plurality of node devices via optical fibers using a set route,
A plurality of optical transceivers that are changed from a standby state to an operating state by being activated, and
An optical transceiver aggregation device that manages the state of the plurality of optical transceivers, and connects an operational optical transceiver to the optical fiber;
Priority determination means for determining the priority of the optical transceiver in the standby state;
For each optical fiber connected to the optical transceiver in the operating state, an operation information output unit that counts the number of set routes and outputs the maximum value among them as a set number M;
Mode setting means for selecting the M units in order of priority from the optical transceivers in the standby state, and setting a high-speed startup standby mode in which the startup time from the standby state is shorter than the allowable time for the communication interruption time;
With
When a failure occurs on the way,
The optical transmitter / receiver aggregation device changes an optical transmitter / receiver in which a failure path is set from an operating state to a standby state, and selects and starts the standby optical transmitters / receivers in order of priority. A node device characterized by the above. The mode setting means is configured so that the standby optical transmitter / receiver that has not been selected has a longer startup time from the standby state than the startup time of the fast startup standby mode, and the power consumption is higher than the power consumption of the fast startup standby mode. The node device according to claim 1, wherein a minimum power standby mode with a smaller value is set. For each optical fiber connected to the optical transceiver in the operating state, further comprising setting information holding means for holding setting information including information on a setting route and a switching destination backup optical fiber,
The operation information output means counts the number of setting routes based on the setting routes held by the setting information holding means,
The optical transmitter / receiver aggregating device specifies a switching-destination optical fiber based on a spare optical fiber held in the setting information holding means when a failure occurs on a route, and selects the activated optical transmitter / receiver. Connect to the specified switching destination optical fiber,
The node device according to claim 1 or 2. The optical transmitter / receiver aggregation device changes the optical transmitter / receiver in which a failure path is set to a standby state and starts the standby optical transmitter / receiver in order of priority, and then again,
The operation information output means outputs a set number M,
The priority determining means determines the priority;
The mode setting means sets the mode of the optical transceiver in a standby state;
The node device according to claim 1. Comprising a plurality of optical transceiver aggregation devices,
The operation information output means extracts the maximum value of the number of set routes for each of the optical transceiver aggregation devices, and outputs the setting number M for each of the optical transceiver aggregation devices,
The node device according to claim 1. The node device according to claim 5, wherein the operation information output unit handles a plurality of optical transceiver aggregation devices that manage connection of the same optical transceiver as one optical transceiver aggregation device. The operation information output means includes
Instead of outputting the maximum value among the number of set paths counted for each optical fiber connected to the optical transceiver in the operating state as the set number M,
Receiving the set route number for every optical fiber through which the set route passes, and outputting the maximum value among the received set route numbers as the set number M;
The node device according to any one of claims 1 to 6. The said operation information output means counts the number of setting paths for every wavelength currently used in the said optical fiber, and outputs the maximum value in it as the setting number M, The any one of Claim 1 thru | or 7 Node equipment. 9. An optical network system in which a plurality of node devices according to claim 1 are connected to each other by optical fibers. A failure recovery control method in a node device that communicates with a plurality of node devices via an optical fiber using a set route,
The node device manages a plurality of optical transmitters / receivers that are changed from a standby state to an operating state by being activated, and connects the optical transceivers in the operating state to the optical fiber. An optical transceiver aggregation device that
Determine the priority of the optical transceiver in the standby state,
For each optical fiber connected to the operating optical transceiver, count the number of set routes, and output the maximum value among them as the set number M,
Select the M units in order of priority from the optical transceivers in the standby state, and set a high-speed startup standby mode in which the startup time from the standby state is shorter than the allowable time of communication interruption time,
When a failure occurs on a route, the optical transmitter / receiver aggregation device is used to change the optical transmitter / receiver in which the route in which the failure occurred is set from the operating state to the standby state and to change the standby state of the optical transmitter / receiver. Select and start in order of priority,
A failure recovery control method in a node device.