WO2019220613A1 - Management device, communication system, control method and control program - Google Patents

Abstract

A management device (100) connects to an optical mesh network that includes: a plurality of nodes for which the path of a light signal can be switched; and an optical transmission path which mutually connects the plurality of nodes. The management device (100) includes: a communication unit (170) that connects to the optical mesh network and, when a wavelength multiplex optical signal path has been selected on a path going through a first node and a second node, from among the plurality of nodes, receives a first fault notification indicating that a fault has occurred in a first optical transmission path connecting to the first node and the second node; an alternative path selection unit (191) that, if a fault occurs on the first optical transmission path, selects a plurality of alternative paths not including the first optical transmission path on the basis of alternative path information indicating an alternative path; and an optical path switching unit (140) that instructs nodes included in the plurality of alternative paths to switch the paths of a plurality of optical signals obtained by dividing the wavelength multiplex optical signal, such paths being switched to respectively different paths on the basis of the plurality of alternative paths.

Description

Management device, communication system, control method, and control program

The present invention relates to a management device, a communication system, a control method, and a control program.

A network for optical communication has been established. For example, in the network, in order to ensure high reliability, there may be a case where one protection line is associated with one operation line. That is, the network has a redundant configuration.
Here, a technology has been proposed in which communication is bypassed to an external network when a failure occurs in both the operation line and the protection line (see Patent Document 1).

Japanese Patent Laid-Open No. 2004-40718

By the way, a plurality of multiplexed optical signals are communicated via an optical fiber. When a failure occurs in the optical fiber, a route search is performed. For example, the route search is performed by the following method. One route is selected. Then, whether or not the paths of the plurality of optical signals can be switched to the selected path is examined. If a plurality of optical signal paths cannot be switched to the selected path, one new path is selected. Then, whether or not the paths of the plurality of optical signals can be switched to the selected path is examined. In this way, the route search is repeated many times until the routes of the plurality of optical signals can be switched to the selected route. This method is likely to repeat the route search many times. Repeating route search many times results in prolonged communication failure.

The object of the present invention is to shorten the period of communication failure.

A management apparatus according to an aspect of the present invention is provided. The management apparatus is connected to an optical mesh network including a plurality of nodes capable of switching optical signal paths and an optical transmission path connecting the plurality of nodes to each other. The management apparatus is connected to the optical mesh network, and when the wavelength multiplexed optical signal path is selected as a path passing through the first node and the second node of the plurality of nodes, A communication unit that receives a first failure notification indicating that a failure has occurred in a first optical transmission line connected to the second node and the second node; and a failure has occurred in the first optical transmission line An alternative path selection unit that selects a plurality of alternative paths not including the first optical transmission path based on alternative path information indicating an alternative path, and an optical signal obtained by dividing the wavelength multiplexed optical signal into a plurality of parts And an optical path switching unit for instructing nodes included in the plurality of alternative routes via the communication unit to switch the routes to different routes based on the plurality of alternative routes.

According to the present invention, the communication failure period can be shortened.

1 is a diagram illustrating a communication system according to a first embodiment. 2 is a diagram illustrating a hardware configuration of the management apparatus according to the first embodiment. FIG. 2 is a functional block diagram illustrating a configuration of a management apparatus according to Embodiment 1. FIG. 3 is a functional block diagram illustrating a configuration of a node according to the first embodiment. FIG. 6 is a diagram illustrating a specific example of route search according to the first embodiment. FIG. 4 is a flowchart illustrating route search processing according to the first embodiment. FIG. 6 is a functional block diagram illustrating a configuration of a management device according to a second embodiment. 10 is a flowchart illustrating route search processing according to the second embodiment.

Hereinafter, embodiments will be described with reference to the drawings. The following embodiments are merely examples, and various modifications can be made within the scope of the present invention.

Embodiment 1 FIG.
FIG. 1 is a diagram illustrating a communication system according to the first embodiment. The communication system includes a management apparatus 100 and nodes 200a to 200l. The management apparatus 100 and the nodes 200a to 200l communicate via a network. For example, the management apparatus 100 and the nodes 200d, 200e, and 200j communicate via a network. Although not shown in FIG. 1, the management apparatus 100 and the node 200a communicate with each other via a network. For example, the network may be a LAN (Local Area Network) or a WAN (Wide Area Network).

The management device 100 is a device that executes a control method. The management apparatus 100 acquires information from the nodes 200a to 200l. For example, the management apparatus 100 acquires information indicating the states of the nodes 200a to 200l from the nodes 200a to 200l. The management apparatus 100 manages setting information set in the nodes 200a to 200l.

The nodes 200a to 200l are associated with identification numbers “# 1” to “# 12”. For example, “# 1” is associated with the node 200a. Hereinafter, the nodes 200a to 200l may be expressed by identification numbers.

Nodes 200a to 200l are connected in a mesh shape. That is, the network constructed by the nodes 200a to 200l is a mesh network. Further, the nodes 200a to 200l are connected to each other through an optical fiber. Therefore, the mesh network constructed by the nodes 200a to 200l is also called an optical mesh network. That is, the optical mesh network includes a plurality of nodes and optical fibers. Here, the optical fiber is also called an optical transmission line.

The nodes 200a to 200l transmit optical signals in which a plurality of wavelengths are multiplexed (that is, wavelength multiplexed optical signals). The optical signal is a signal obtained by converting an electrical signal transmitted from a client device (not shown). The optical signal is communicated by wavelength division multiplexing. The nodes 200a to 200l can also separate an optical signal in which a plurality of wavelengths are multiplexed. The nodes 200a to 200l can switch optical signal paths.
In addition, the management apparatus 100 can switch the path of an optical signal transmitted through the optical mesh network.

Next, the main hardware configuration of the management apparatus 100 will be described.
FIG. 2 is a diagram illustrating a hardware configuration of the management apparatus according to the first embodiment. The management device 100 includes a processor 101, a volatile storage device 102, and a nonvolatile storage device 103.

The processor 101 controls the entire management apparatus 100. For example, the processor 101 is a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array). The processor 101 may be a multiprocessor. The management device 100 may be realized by a processing circuit, or may be realized by software, firmware, or a combination thereof. The processing circuit may be a single circuit or a composite circuit.

The volatile storage device 102 is a main storage device of the management device 100. For example, the volatile storage device 102 is a RAM (Random Access Memory). The nonvolatile storage device 103 is an auxiliary storage device of the management device 100. For example, the non-volatile storage device 103 is an HDD (Hard Disk Drive) or an SSD (Solid State Drive).

As with the management apparatus 100, the nodes 200a to 200l have a processor, a volatile storage device, and a nonvolatile storage device.

Next, functions of the management apparatus 100 will be described.
FIG. 3 is a functional block diagram illustrating a configuration of the management apparatus according to the first embodiment. The management apparatus 100 includes a storage unit 110, a device configuration management unit 120, an optical path management unit 130, an optical path switching unit 140, a failure management unit 150, a performance management unit 160, a communication unit 170, a route status accumulation unit 180, and a route search. Part 190. The route search unit 190 includes an alternative route selection unit 191 and a grouping unit 192.

The storage unit 110 and the path status storage unit 180 are realized as a storage area secured in the volatile storage device 102 or the nonvolatile storage device 103.
Device configuration management unit 120, optical path management unit 130, optical path switching unit 140, failure management unit 150, performance management unit 160, communication unit 170, route search unit 190, alternative route selection unit 191, and part of grouping unit 192 Alternatively, all may be realized by the processor 101. Device configuration management unit 120, optical path management unit 130, optical path switching unit 140, failure management unit 150, performance management unit 160, communication unit 170, route search unit 190, alternative route selection unit 191, and part of grouping unit 192 Alternatively, all may be realized as a module of a program executed by the processor 101. This program is also called a control program.

The storage unit 110 stores various information. The device configuration management unit 120 manages package information indicating transponders stored in the nodes 200a to 200l. The package information includes information indicating the wavelength handled by each transponder. For example, the package information is stored in the storage unit 110.

The optical path management unit 130 manages route information indicating the route through which the optical signal of each wavelength is transmitted. That is, the route information is information indicating the current route status. For example, the route information is stored in the storage unit 110.

Also, the optical path management unit 130 manages alternative route information. The alternative route information is information indicating a plurality of alternative routes. Further, the alternative path information may be expressed as information indicating which path the optical signal path is switched to when a failure occurs in the optical transmission path or when a failure occurs in the node. In addition, a priority is associated with the alternative route indicated by the alternative route information. Here, the priority is determined based on the number of nodes included in the alternative route. For example, the priority becomes higher as the number of nodes included in the route is smaller. Further, for example, the alternative route information is stored in the storage unit 110 in advance.

The optical path switching unit 140 switches optical signal paths via the communication unit 170. The optical path switching unit 140 manages the path switching status.
The failure management unit 150 may acquire a failure notification from the nodes 200a to 200l via the communication unit 170. The performance management unit 160 manages the performance information of the nodes 200a to 200l. For example, the performance information is stored in the storage unit 110.

The communication unit 170 communicates with the nodes 200a to 200l. That is, the communication unit 170 is connected to the optical mesh network.
The communication unit 170 is connected to the device configuration management unit 120, the optical path management unit 130, the optical path switching unit 140, the failure management unit 150, the performance management unit 160, and the route search unit 190. In FIG. 3, illustration that the communication unit 170 is connected to the device configuration management unit 120 and the like is omitted.

The communication unit 170 determines whether the wavelength multiplexed optical signal path is selected as a path that passes through the first node and the second node among the plurality of nodes. A failure notification indicating that a failure that hinders transmission of the wavelength multiplexed optical signal has occurred in the first optical transmission line to be connected is received.

The route status storage unit 180 stores route status information. The route status information indicates whether or not the alternative route indicated by the alternative route information is normal. The initial state of the route status information indicates that all routes are normal.
The route search unit 190 performs route search when a failure occurs in the optical transmission path between the nodes or when a failure occurs in the node. When a failure occurs in the first optical transmission path, the alternative path selection unit 191 selects a plurality of alternative paths that do not include the first optical transmission path based on the alternative path information.

Further, after the alternative path selection unit 191 selects a plurality of alternative paths, the optical path switching unit 140 changes the path of the optical signal obtained by dividing the wavelength multiplexed optical signal into a plurality of paths based on the plurality of alternative paths. The node included in the plurality of alternative routes is instructed via the communication unit 170 to switch to the route.

Here, an optical signal obtained by dividing a wavelength multiplexed optical signal into a plurality of parts will be described. For example, when the number of wavelengths based on a wavelength multiplexed optical signal is 10, it may be divided into 10 optical signals, or an optical signal in which 8 wavelengths are multiplexed and 2 wavelengths are multiplexed. You may divide | segment into an optical signal.

For example, when the number of wavelengths based on the wavelength multiplexed optical signal is 10, and the optical signal is divided into 10 optical signals, the optical path switching unit 140 instructs as follows. The optical path switching unit 140 is configured to switch a plurality of optical signal paths having different wavelengths based on the wavelength multiplexed optical signal to different paths based on the plurality of alternative paths through the communication unit 170. Instruct nodes included in alternate routes.
The function of the grouping unit 192 will be described in detail later.

Next, the function of the node will be described. Here, the nodes 200a to 200l are collectively referred to as a node 200. The node function will be described using the node 200.
FIG. 4 is a functional block diagram illustrating the configuration of the node according to the first embodiment. The node 200 includes a node monitoring control unit 210, an optical node unit 220, and a transponder unit 230.

The node monitoring control unit 210 includes a storage unit 211, a device configuration management unit 212, an optical path management unit 213, an optical path switching unit 214, a failure management unit 215, a performance management unit 216, and a communication unit 217.
The optical node unit 220 includes optical amplification units 221a to 221h and wavelength selection switch units 222a to 222h.

The storage unit 211 is realized as a storage area secured in a volatile storage device or a nonvolatile storage device included in the node 200.
Part or all of the device configuration management unit 212, the optical path management unit 213, the optical path switching unit 214, the failure management unit 215, the performance management unit 216, and the communication unit 217 may be realized by a processor included in the node 200. . Some or all of the device configuration management unit 212, the optical path management unit 213, the optical path switching unit 214, the failure management unit 215, the performance management unit 216, and the communication unit 217 are modules of programs executed by the processor included in the node 200. It may be realized as.

The storage unit 211 stores various information. The device configuration management unit 212 manages the transponder package information stored in the node 200. The package information includes information indicating the wavelength handled by the transponder. For example, the package information is stored in the storage unit 211.

The optical path management unit 213 manages information regarding the optical fiber to which the node 200 is connected. The optical path switching unit 214 can change the path of the optical signal by controlling the wavelength selective switch units 222a to 222h.
The failure management unit 215 manages alarm information such as a transponder. For example, the alarm information is stored in the storage unit 211.

The performance management unit 216 manages the performance information of the transponders included in the optical amplification units 221a to 221h, the wavelength selection switch units 222a to 222h, and the transponder unit 230. For example, the performance information is stored in the storage unit 211.

The communication unit 217 communicates with the management apparatus 100. The communication unit 217 is connected to the device configuration management unit 212, the optical path management unit 213, the optical path switching unit 214, the failure management unit 215, and the performance management unit 216. In FIG. 4, illustration that the communication unit 217 is connected to the device configuration management unit 212 and the like is omitted.

The optical amplifiers 221a to 221d amplify the optical signal input to the node 200. The optical amplifiers 221a to 221d input the amplified optical signals to the wavelength selective switch units 222a to 222d. Further, the optical amplification units 221e to 221h can amplify the optical signals output from the wavelength selective switch units 222e to 222h. The optical amplification units 221e to 221h output the amplified optical signal to the outside.

The wavelength selective switch units 222a to 222h branch the optical signal by wavelength multiplexing. The wavelength selective switch units 222a to 222h can execute an optical cross-connect. For example, the wavelength selective switch units 222a to 222d output optical signals to the transponder unit 230. The wavelength selective switch units 222e to 222h change the traveling direction of the optical signal input from the transponder unit 230.

The transponder unit 230 includes transponders 231 to 234. The transponders 231 to 234 can convert electrical signals received from client devices into optical signals. The transponders 231 to 234 can also multiplex optical signals.

Each of the transponders 231 to 234 has a predetermined wavelength. For example, the transponder 231 is in charge of lambda ₁ of the optical signal. Therefore, for example, the wavelength selective switch units 222 a to 222 d may output an optical signal of λ ₁ to the transponder 231.
FIG. 4 illustrates four transponders. However, the number of transponders is not limited to four.

FIG. 5 is a diagram illustrating a specific example of the route search according to the first embodiment. Nodes 200a to 200d are active nodes. That is, the nodes 200a to 200d are active nodes. Nodes 200e to 200l are standby nodes. That is, the nodes 200e to 200l are standby nodes. The standby system may be expressed as a non-operational system.

The nodes 200a to 200d transmit a plurality of optical signals in which different wavelengths are multiplexed. For example, the nodes 200a to 200d transmit λ ₁ and λ ₂ optical signals.
Here, for example, the node 200b may be expressed as a first node. The node 200c may be expressed as a second node. In FIG. 5, it is assumed that the path of the wavelength multiplexed optical signal (that is, the optical signal of λ ₁ and λ ₂ ) is selected as the path passing through the first node and the second node.

Next, route search will be described using a flowchart. In the description of the flowchart, FIG. 5 is used.
FIG. 6 is a flowchart showing a route search process according to the first embodiment. Note that FIG. 6 refers to FIGS.

Here, for example, it is assumed that a failure has occurred in the optical transmission path (for example, the first optical transmission path) between the node # 2 (that is, the node 200b) and the node # 3 (that is, the node 200c). When a failure occurs in the optical transmission line, a node downstream from the location where the failure occurs detects the failure. For example, when the optical amplification unit of the node # 3 (that is, the node 200c) detects that the power of the optical signal input to the node # 3 is weak, it detects that a failure has occurred in the optical transmission line. To do. The optical amplification unit at node # 3 notifies the failure management unit at node # 3 that a failure has occurred in the optical transmission path between node # 2 and node # 3. The failure management unit of node # 3 transmits a failure notification to the management apparatus 100 via the communication unit of node # 3. The failure notification indicates that a failure has occurred in the optical transmission path between the node # 2 and the node # 3.

(Step S11) The communication unit 170 receives a failure notification. The failure notification is also referred to as a first failure notification. In addition, the communication unit 170 may receive the failure notification transmitted from the node # 3 from a device (not shown).

(Step S12) The optical path management unit 130 identifies the wavelength of the optical signal that cannot be transmitted based on the route information and the failure notification. For example, in the path information, it is registered that a part of the optical signal paths of λ ₁ and λ ₂ is an optical transmission path between the node # 2 and the node # 3. Based on the path information and the failure notification, the optical path management unit 130 specifies that the wavelengths of the optical signals that cannot be transmitted are λ ₁ and λ ₂ .
The alternative path selection unit 191 acquires wavelength information indicating the wavelength of the optical signal that cannot be transmitted from the optical path management unit 130.

The alternative route selection unit 191 acquires alternative route information from the optical path management unit 130. The alternative route selection unit 191 acquires route status information from the route status storage unit 180. The alternative route selection unit 191 selects the route of the optical signal that cannot be transmitted based on the alternative route information and the route status information. Note that, when selecting a route, the alternative route selection unit 191 excludes a route including an optical transmission path in which a failure has occurred (for example, an optical transmission path between the node # 2 and the node # 3). Further, when selecting a route, the alternative route selection unit 191 selects a route having the number of wavelengths of the optical signal that cannot be transmitted. Furthermore, when selecting a route, the alternative route selection unit 191 selects a route in descending order of priority.

Detailed explanation. For example, the alternative route selection unit 191 selects a route indicated by the alternative route information from normal alternative routes indicated by the route status information. The alternative route selection unit 191 excludes a route including the optical transmission line in which the failure has occurred from the selected routes. The alternative route selection unit 191 selects a route having the number of wavelengths of the optical signal that cannot be transmitted, from the excluded routes in descending order of priority.

For example, the alternative path selection unit 191 specifies the number of wavelengths (that is, λ ₁ and λ ₂ ) of the optical signal that cannot be transmitted based on the wavelength information. Since the number of wavelengths of the optical signal that cannot be transmitted is two, the alternative path selection unit 191 selects two paths. The selected routes are route A and route B. The route A is a route of the nodes # 1, # 2, # 6, # 7, # 3, and # 4. The route B is a route of the nodes # 1, # 2, # 10, # 11, # 3, and # 4.
As described above, the alternative route selection unit 191 selects a plurality of alternative routes having the number of wavelengths based on the wavelength multiplexed optical signal based on the alternative route information.

Further, the alternative path selection unit 191 does not have to select a path having the number of wavelengths of the optical signal that can no longer be transmitted. For example, the alternative path selection unit 191 selects two paths A and B when the number of wavelengths of the optical signal that cannot be transmitted is three. Then, the alternative path selection unit 191 may select the path of the optical signal having the two wavelengths as the path A and select the path of the remaining one wavelength as the path B.

(Step S13) The grouping unit 192 groups the routes selected by the alternative route selection unit 191. For example, the grouping unit 192 groups the route A and the route B. The grouped information is referred to as grouping information.

(Step S <b> 14) The optical path switching unit 140 acquires wavelength information from the optical path management unit 130. The optical path switching unit 140 acquires information indicating the route selected from the alternative route selection unit 191. The optical path switching unit 140 acquires grouping information from the grouping unit 192.
The optical path switching unit 140 transmits a switching command to the nodes included in the route selected by the alternative route selection unit 191. The switching command includes information indicating the wavelengths (for example, λ ₁ and λ ₂ ) of the optical signal that cannot be transmitted.

As described above, the optical path switching unit 140 is configured to transmit a plurality of optical signal paths obtained by dividing the wavelength multiplexed optical signal into a plurality of paths via the communication unit 170 so as to switch to different paths based on the plurality of alternative paths. Instruct the nodes included in the alternative route.

Thereby, for example, the optical path switching unit of the node 200b receives the switching command via the communication unit of the node 200b. The optical path switching unit of the node 200b acquires package information from the device configuration management unit 212. Based on the switching command and the package information, the optical path switching unit of the node 200b identifies the transponder that is responsible for the wavelength of the optical signal that cannot be transmitted. The optical path switching unit of the node 200b transmits an optical signal path switching instruction to the transponder and the wavelength selection switch unit of the node 200b. As a result, the path of the optical signal is changed. For example, the optical signal of λ ₁ travels along path A. The optical signal of λ ₂ travels along the path B.

Here, the optical path switching unit 140 transmits the grouping information to the node 200d (that is, the node # 4). Here, the node 200d is also referred to as a monitoring node that monitors an optical signal.

The optical path switching unit of the node 200d monitors whether or not an optical signal can be received via a monitoring time that is a predetermined time and a route indicated by the grouping information. The optical path switching unit of the node 200d determines that the path of the optical signal is a normal path when the optical signal can be received within the monitoring time. The optical path switching unit of the node 200d determines that the path of the optical signal is an abnormal path when the optical signal cannot be received within the monitoring time. For example, the optical path switching unit of the node 200d determines that the route A is a normal route when the optical signal of λ ₁ is received within the monitoring time. Light path switching unit of the node 200d determines within the monitoring time, if it can not receive the lambda ₂ of the optical signal, a path B and aberrant pathways.

The optical path switching unit of the node 200d transmits the monitoring result information to the management apparatus 100 via the communication unit of the node 200d. For example, the monitoring result information includes information indicating that the route A is a normal route and the route B is an abnormal route.
Here, the monitoring result information may be expressed as information indicating whether or not the node 200d has received each of the plurality of divided optical signals transmitted through the plurality of alternative paths.

(Step S15) The communication unit 170 receives the monitoring result information.
(Step S16) The optical path switching unit 140 updates the route status information based on the monitoring result information. Thereby, when there is an abnormal route, the abnormal route is registered in the route status information. The optical path switching unit 140 may not update the route status information when all the routes selected by the alternative route selection unit 191 are normal routes.

(Step S17) Based on the monitoring result information, the optical path switching unit 140 determines whether all the routes selected by the alternative route selection unit 191 are abnormal. For example, the optical path switching unit 140 determines whether both the routes A and B are abnormal.

When the condition of step S17 is not satisfied (No in step S17), the optical path switching unit 140 advances the process to step S18.
When the condition of step S17 is satisfied (Yes in step S17), the optical path switching unit 140 discards the grouping information. Then, the optical path switching unit 140 proceeds with the process to step S12. In step S12, the alternative route selection unit 191 selects a new route based on the route status information and the alternative route information updated in step S16. The new path excludes the path including the optical transmission path where the failure has occurred. Further, the alternative route selection unit 191 selects a route in descending order of priority among routes not selected in the previous step S12.

(Step S18) The optical path switching unit 140 determines whether there is an abnormal route among the routes selected by the alternative route selection unit 191 based on the monitoring result information.
If there is an abnormal route (Yes in step S18), the optical path switching unit 140 advances the process to step S19. If there is no abnormal route (No in step S18), the optical path switching unit 140 ends the route search.

(Step S19) The optical path switching unit 140 switches the path of the optical signal to which the abnormal path is assigned to the normal path among the paths selected by the alternative path selection unit 191. For example, when the route A is a normal route and the route B is an abnormal route, the optical path switching unit 140 switches the route of the optical signal of λ ₂ to the route A.

In addition, when switching a path | route, the optical path switching part 140 transmits a switching command to a node. The switching instruction includes information indicating the lambda _2. Thereby, for example, the optical path switching unit of the node 200b receives the switching command via the communication unit of the node 200b. The optical path switching unit of the node 200b acquires package information from the device configuration management unit 212. The optical path switching unit of the node 200b specifies the transponder responsible for λ ₂ based on the switching command and the package information. The optical path switching unit of the node 200b transmits a path switching instruction of the optical signal of λ _{2 to} the transponder and the wavelength selection switch unit of the node 200b. As a result, the optical signal of λ ₂ travels along the path A.

As described above, the optical path switching unit 140 does not receive at least one optical signal among the optical signals divided by the node 200d based on the monitoring result information, and the node 200d is divided into the plurality of optical signals. When at least one of the received optical signals is received, the communication unit 170 switches the alternative path of the optical signal not received by the node 200d to the alternative path of the optical signal received by the node 200d. The node 200d instructs the node included in the alternative path of the optical signal received by the node 200d. As a result, the management apparatus 100 does not have to search again for the path of the optical signal that the node 200d did not receive, so the communication failure period can be shortened. This content can also be applied when a failure occurs in a node.

The optical path switching unit 140 may switch the path of the optical signal to which the abnormal path is assigned to the path having the highest priority among the normal paths. For example, it is assumed that the routes selected by the alternative route selection unit 191 are routes A, B, and C. The path C is not shown in FIG. Routes A and C are normal routes. The route B is an abnormal route. Further, of the routes A and C, the route A is the route with the highest priority. The optical path switching unit 140 switches the path of the optical signal of λ ₂ to the path A.

Thus, the optical path switching unit 140 does not receive at least one of the optical signals divided by the node 200d, and at least of the optical signals divided by the node 200d. When one optical signal is received, the alternative path of the optical signal that could not be received by the node 200d is switched to the alternative path having the highest priority among the alternative paths of the optical signal received by the node 200d. An instruction is given to a node included in an alternative route having the highest priority via the communication unit 170. As a result, the management apparatus 100 does not have to search again for the path of the optical signal that the node 200d did not receive, so the communication failure period can be shortened. Furthermore, the management apparatus 100 can switch the path of the optical signal that has not been received by the node 200d to a path that shortens the time until the node 200d receives the optical signal. This content can also be applied when a failure occurs in a node.

Note that the monitoring time monitored by the optical path switching unit of the node 200d can be arbitrarily changed.
In the case of No in step S18, the optical path switching unit 140 may switch the path of the optical signal to which another normal path is assigned to the path having the highest priority among the normal paths. For example, routes A, B, and C are normal routes. Among routes A, B, and C, route A is the route with the highest priority. The optical path switching unit 140 switches the path of the optical signal to which the paths B and C are assigned to the path A. As described above, the optical path switching unit 140 switches the path of the optical signal to which the paths B and C are assigned to the path A by transmitting a switching command to the nodes included in the paths B and C. it can.

As described above, when the node 200d receives all of the optical signals divided into a plurality of parts based on the monitoring result information, the optical path switching unit 140 has the highest priority among the alternative paths of the divided optical signals. Through the communication unit 170, the highest priority is switched so that the alternative path of the optical signal other than the optical signal transmitted through the alternative path with the highest priority among the optical signals divided into a plurality of parts is switched to the higher alternative path. Instruct the nodes included in the alternate route with high frequency. Thereby, since all the optical signals are transmitted to one path | route, the management apparatus 100 can manage the transmission condition of an optical signal easily. Furthermore, the management apparatus 100 can switch the path of all optical signals to a path that shortens the time until the node 200d receives the optical signal. This content can also be applied when a failure occurs in a node.

FIG. 6 illustrates the case where a failure occurs in the optical transmission line. Even when a failure occurs in a node, the management apparatus 100 can execute a route search based on the alternative route information and the route status information. For example, the communication unit 170 receives a failure notification indicating that a failure has occurred in the first node. The failure notification is also referred to as a second failure notification. The alternative route selection unit 191 selects a plurality of alternative routes that do not include the first node based on the alternative route information. The optical path switching unit 140 switches the communication unit 170 so that the path of the optical signal obtained by dividing the wavelength multiplexed optical signal into a plurality of paths is switched to a different path based on the plurality of alternative paths selected by the alternative path selection unit 191. Through this, the alternative route selection unit 191 instructs the nodes included in the plurality of alternative routes selected.

Here, for example, it is assumed that a failure occurs in the optical transmission path, and the management apparatus switches the path of the optical signals of λ ₁ and λ ₂ to the path A. When the path A is an abnormal path, the management apparatus switches the optical signal paths of λ ₁ and λ ₂ to the path B and examines whether the path B is normal. As described above, when the plurality of optical signals are switched to one route and the route is an abnormal route, the management device repeats the route search many times. Repeating route search many times results in prolonged communication failure.

Therefore, according to the first embodiment, the management device 100 searches for a route by switching the route of the optical signal obtained by dividing the wavelength-division-multiplexed optical signal into a plurality of different routes, so that a normal route can be efficiently and early. Can be detected. That is, the management apparatus 100 can reduce the possibility of repeating the route search many times. The management device 100 can detect a normal path at an early stage so that a plurality of optical signals can pass through the normal path at an early stage. Therefore, the management apparatus 100 can shorten the communication failure period.

In addition, the management apparatus 100 selects a normal route among the alternative routes indicated by the alternative route information by selecting a route based on the route status information and the alternative route information. Thereby, the management apparatus 100 can prevent selecting an abnormal route from among the alternative routes indicated by the alternative route information. That is, the management apparatus 100 can reduce the possibility of repeating the route search by not selecting an abnormal route.

Also, the priority becomes higher as the number of nodes included in the route is smaller. Therefore, the management apparatus 100 can select a path that shortens the time until the node 200d receives an optical signal by selecting a path in descending order of priority.

Embodiment 2. FIG.
Next, a second embodiment will be described. Items that are different from the first embodiment will be mainly described, and description of matters that are common to the first embodiment will be omitted. In the description of the second embodiment, reference is made to FIGS.
In the first embodiment, the case where the route search is performed using the alternative route information has been described. In the second embodiment, a case where a route search is performed without using alternative route information will be described.

FIG. 7 is a functional block diagram illustrating the configuration of the management apparatus according to the second embodiment. The management device 100a includes a route search unit 190a. The route search unit 190a includes an alternative route selection unit 191a. The function of the alternative route selection unit 191a will be described later.

Further, part or all of the alternative route selection unit 191a may be realized by the processor 101. A part or all of the alternative path selection unit 191a may be realized as a module of a program executed by the processor 101.
7 that is the same as or corresponds to the configuration shown in FIG. 3 is assigned the same reference numeral as that shown in FIG.

FIG. 8 is a flowchart showing route search processing according to the second embodiment. The process of FIG. 8 differs from the process of FIG. 6 in that steps S11a, 12a, and 17a are executed. Therefore, FIG. 8 demonstrates step S11a, 12a, 17a. The other steps in FIG. 8 are given the same numbers as the step numbers in FIG. Note that the alternative route selection unit 191a executes the alternative route selection unit 191 that executes the processing of FIG. Also, FIG. 8 refers to FIGS.

(Step S11a) The alternative route selection unit 191a calculates a plurality of routes.
For example, the alternative route selection unit 191a calculates a plurality of routes in ascending order of optical signal transmission routes. Further, the alternative route selection unit 191a may calculate a route in which the length of the optical signal transmission route is shorter than the threshold value. The alternative route selection unit 191a can select a route that shortens the time until the node 200d receives the optical signal by calculating a route having a short transmission route. The alternative route selection unit 191a associates a priority with the calculated route based on the calculated length of the route and the number of nodes included in the calculated route. For example, the alternative path selection unit 191a increases the priority as the optical signal transmission path is shorter and the number of nodes included in the path is smaller.

Also, for example, the alternative route selection unit 191a calculates a plurality of routes in ascending order of the number of nodes present in the optical signal transmission route. Alternatively, the alternative route selection unit 191a may calculate a route in which the number of nodes included in the optical signal transmission route is less than a threshold value. The alternative route selection unit 191a can select a route that shortens the time until the node 200d receives an optical signal by calculating a route with a small number of nodes. Further, the alternative route selection unit 191a gives priority to the calculated routes in the order.

情報 Information related to a plurality of calculated routes is called route calculation information. The route calculation information includes priority information associated with each route.

(Step S12a) The optical path management unit 130 identifies the wavelength of the optical signal that cannot be transmitted based on the route information and the failure notification. The alternative path selection unit 191a acquires wavelength information indicating the wavelength of the optical signal that cannot be transmitted from the optical path management unit 130.

The alternative route selection unit 191a acquires route status information from the route status storage unit 180. The alternative path selection unit 191a selects the path of the optical signal that cannot be transmitted based on the path calculation information and the path status information. Note that, when selecting a route, the alternative route selection unit 191a excludes a route including an optical transmission line in which a failure has occurred. In addition, when selecting a route, the alternative route selection unit 191a selects a route having the number of wavelengths of the optical signal that cannot be transmitted. Furthermore, when selecting a route, the alternative route selection unit 191a selects a route in descending order of priority.

Detailed explanation. For example, the alternative route selection unit 191a selects a normal route from the routes indicated by the route calculation information based on the route status information. The alternative route selection unit 191a excludes a route including an optical transmission line in which a failure has occurred from normal routes. The alternative path selection unit 191a selects a path having the number of wavelengths of the optical signal that can no longer be transmitted from the excluded paths in descending order of priority.

(Step S17a) The optical path switching unit 140 determines whether or not all the routes selected by the alternative route selection unit 191a are abnormal based on the monitoring result information.

When the condition of step S17a is not satisfied (No in step S17a), the optical path switching unit 140 proceeds with the process to step S18.
When the condition of step S17a is satisfied (Yes in step S17a), the optical path switching unit 140 discards the grouping information. Then, the optical path switching unit 140 proceeds with the process to step S12a. In step S12a, the alternative route selection unit 191a selects a new route based on the route status information and the route calculation information updated in step S16. The new route excludes a route including the optical transmission line where the failure has occurred. In addition, the alternative route selection unit 191a selects routes in descending order of priority among routes not selected in the previous step S12a.

Since the management device 100a does not need to store alternative route information, the amount of data stored in the management device 100a can be reduced. Further, the management device 100a can recover from a communication failure early without using the alternative route information.

The management apparatus 100a can execute a route search based on the route calculation information and the route status information even when a failure occurs in the node.

The features in the embodiments described above can be appropriately combined with each other.

100, 100a management device, 101 processor, 102 volatile storage device, 103 nonvolatile storage device, 110 storage unit, 120 device configuration management unit, 130 optical path management unit, 140 optical path switching unit, 150 fault management unit, 160 performance Management unit, 170 communication unit, 180 route status storage unit, 190, 190a route search unit, 191, 191a alternative route selection unit, 192 grouping unit, 200 nodes, 200a-200l node, 210 node monitoring control unit, 211 storage unit, 212 device configuration management unit, 213 optical path management unit, 214 optical path switching unit, 215 fault management unit, 216 performance management unit, 217 communication unit, 220 optical node unit, 221a to 221h optical amplification unit, 22a ~ 222h wavelength selection switch section, 230 transponder, 231, 232, 233, 234 transponders.

Claims (15)

A management device for connecting to an optical mesh network including a plurality of nodes capable of switching a path of an optical signal and an optical transmission path for connecting the plurality of nodes to each other,
When a path of a wavelength multiplexed optical signal is selected as a path connected to the optical mesh network and passing through a first node and a second node of the plurality of nodes, the first node and the A communication unit that receives a first failure notification indicating that a failure has occurred in the first optical transmission line connected to the second node;
An alternative path selection unit that selects a plurality of alternative paths not including the first optical transmission line based on alternative path information indicating an alternative path when a failure occurs in the first optical transmission path;
Nodes included in the plurality of alternative paths via the communication unit so as to switch the path of the optical signal obtained by dividing the wavelength-multiplexed optical signal into a plurality of paths based on the plurality of alternative paths. An optical path switching unit for instructing to
A management device. When selecting the plurality of alternative paths, the alternative path selection unit selects an alternative path having the number of wavelengths based on the wavelength multiplexed optical signal based on the alternative path information;
The optical path switching unit, via the communication unit, to switch the path of a plurality of optical signals of different wavelengths based on the wavelength-multiplexed optical signal to different paths based on the plurality of alternative paths, Directing nodes included in the plurality of alternative paths;
The management apparatus according to claim 1. The alternative route selection unit is configured to select one of the normal alternative routes indicated by the route status information based on the route status information indicating whether the alternative route indicated by the alternative route information is normal and the alternative route information. Selecting the plurality of alternative routes from
The management device according to claim 1 or 2. The alternative route indicated by the alternative route information is associated with a priority determined based on the number of nodes included in the alternative route,
The alternative route selection unit selects the plurality of alternative routes based on the alternative route information and the priority;
The management device according to any one of claims 1 to 3. The communication unit receives each of the plurality of divided optical signals transmitted through each of the plurality of alternative paths from a monitoring node that monitors the plurality of divided optical signals among the plurality of nodes. Monitoring result information indicating whether or not
The optical path switching unit has not received at least one optical signal among the optical signals divided by the monitoring node based on the monitoring result information, and the monitoring node has the plurality of optical signals. When at least one of the divided optical signals is received, the alternative path of the optical signal not received by the monitoring node is switched to the alternative path of the optical signal received by the monitoring node; Instructing the node included in the alternative path of the optical signal received by the monitoring node via the communication unit,
The management apparatus of any one of Claim 1 to 4. The communication unit receives each of the plurality of divided optical signals transmitted through each of the plurality of alternative paths from a monitoring node that monitors the plurality of divided optical signals among the plurality of nodes. Monitoring result information indicating whether or not
The optical path switching unit has not received at least one optical signal among the optical signals divided by the monitoring node based on the monitoring result information, and the monitoring node has the plurality of optical signals. When at least one of the divided optical signals is received, the monitoring node has not received the alternative path with the highest priority among the alternative paths of the optical signal received by the monitoring node Instructing a node included in the alternative route with the highest priority via the communication unit to switch the alternative route of the optical signal;
The management device according to claim 4. The communication unit receives each of the plurality of divided optical signals transmitted through each of the plurality of alternative paths from a monitoring node that monitors the plurality of divided optical signals among the plurality of nodes. Monitoring result information indicating whether or not
The optical path switching unit, based on the monitoring result information, when the monitoring node receives all of the optical signals divided into the plurality, the priority among the alternative paths of the divided optical signals Through the communication unit so as to switch the alternative path of the optical signal other than the optical signal transmitted through the alternative path with the highest priority among the plurality of divided optical signals to the higher alternative path. Instructing the nodes included in the alternative route with the highest priority,
The management device according to claim 4. The communication unit receives a second failure notification indicating that a failure has occurred in any one of the plurality of nodes;
The alternative route selection unit selects a plurality of alternative routes that do not include a failed node based on the alternative route information,
The optical path switching unit, via the communication unit, to switch the path of the optical signal divided into a plurality of different paths based on the plurality of alternative paths selected by the alternative path selection unit, Instructing nodes included in a plurality of alternative routes selected by the alternative route selection unit,
The management apparatus according to claim 1. The alternative route selection unit calculates a route in which the length of the transmission path of the optical signal is shorter than a threshold, and selects the plurality of alternative routes based on the calculated route.
The management apparatus according to claim 1. The alternative route selection unit associates a priority with the calculated route based on the calculated length of the route and the number of nodes included in the calculated route, and sets the plurality of routes based on the calculated route and the priority. Choose an alternate route for
The management apparatus according to claim 9. The alternative route selection unit calculates a route in which the number of nodes included in the transmission route of the optical signal is less than a threshold, and selects the plurality of alternative routes based on the calculated route;
The management apparatus according to claim 1. The alternative route selection unit associates a priority with the calculated route based on the number of nodes included in the calculated route, and selects the plurality of alternative routes based on the calculated route and the priority. ,
The management apparatus according to claim 11. A plurality of nodes capable of switching optical signal paths;
A management device connected to an optical mesh network including the plurality of nodes and an optical transmission path connecting the plurality of nodes to each other;
Including
The management device
When a path of a wavelength multiplexed optical signal is selected as a path connected to the optical mesh network and passing through a first node and a second node of the plurality of nodes, the first node and the A communication unit that receives a first failure notification indicating that a failure has occurred in the first optical transmission line connected to the second node;
An alternative path selection unit that selects a plurality of alternative paths not including the first optical transmission line based on alternative path information indicating an alternative path when a failure occurs in the first optical transmission path;
Nodes included in the plurality of alternative paths via the communication unit so as to switch the path of the optical signal obtained by dividing the wavelength-multiplexed optical signal into a plurality of paths based on the plurality of alternative paths. An optical path switching unit for instructing to
Having
Communications system. A management device connected to an optical mesh network including a plurality of nodes capable of switching optical signal paths and an optical transmission line connecting the plurality of nodes to each other,
When the path of the wavelength multiplexed optical signal is selected as a path passing through the first node and the second node of the plurality of nodes, the first node and the second node are connected Receiving a first failure notification indicating that a failure has occurred in the first optical transmission line;
Selecting a plurality of alternative routes not including the first optical transmission path based on alternative route information indicating an alternative route;
Instructing the nodes included in the plurality of alternative paths to switch the path of the optical signal obtained by dividing the wavelength-multiplexed optical signal into a plurality of paths based on the plurality of alternative paths, respectively.
Control method. To a management device connected to an optical mesh network including a plurality of nodes capable of switching the path of an optical signal and an optical transmission path connecting the plurality of nodes to each other,
When the path of the wavelength multiplexed optical signal is selected as a path passing through the first node and the second node of the plurality of nodes, the first node and the second node are connected Receiving a first failure notification indicating that a failure has occurred in the first optical transmission line;
Selecting a plurality of alternative routes not including the first optical transmission path based on alternative route information indicating an alternative route;
Instructing the nodes included in the plurality of alternative paths to switch the path of the optical signal obtained by dividing the wavelength-multiplexed optical signal into a plurality of paths based on the plurality of alternative paths, respectively.
A control program that executes processing.

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