JP7611778B2 - Operation device, program, and operation method - Google Patents

Description

This disclosure relates to an operation device, a program, and an operation method.

Conventionally, WDM (Wavelength Division Multiplexer) devices have been used for communications requiring long distances and large capacity, such as intercity transmission.
Conventional WDM devices form a ring-type network, and two paths, one going clockwise and one going counterclockwise, are provided between specific nodes for communication. In the event of a failure or the like occurring in either link, it is common to use an OUPSR (Optical Unidirectional Path Switched Ring) system to switch between the two paths.

When redundancy is ensured for a certain optical path using the OUPSR method, the resources of the current route and the backup route are allocated for that optical path, so the OUPSR method can be applied only when it can be determined that the resources of the current route and the backup route can be secured.

In a ring network, it is necessary to detour around the corresponding location in the optical path not only when a fault occurs, but also when maintenance is performed on the optical fiber of the transmission path or when a node is added due to an increase in traffic.

In a WDM device, a maximum of approximately 100 optical paths can usually be accommodated per transmission line, so a maximum of approximately 100 optical paths need to be rerouted. For this reason, Patent Document 1 discloses a network operation system equipped with a bulk optical path switching function.

JP 2004-247787 A

Conventionally, WDM devices were two-way devices, so only ring or linear network configurations could be used. In recent years, with the spread of WSS (Wavelength Selective Switch), WDM devices have changed to multi-way devices.

As a result, the network configuration changes from a ring network configuration to a mesh network configuration, and the number of possible routes between two nodes can change from a maximum of two routes to multiple routes, which is more than two routes.

As the number of routes increases, optical path redundancy methods are not limited to the OUPSR method; there are also WDM devices equipped with a restoration method that switches to an alternative route in the event of an optical path failure.

There are two common restoration methods: a pre-reservation restoration method, in which a switching destination is selected from multiple pre-set switching routes when a failure occurs, and an autonomous restoration method, in which a switching route is autonomously searched for within the network.

This advance reservation type restoration method makes it possible to set up multiple backup routes. Furthermore, even if a backup route is set up for an optical path using the advance reservation type restoration method, the resources of the backup route are not allocated to that optical path, and it is possible to set up backup routes for other optical paths using the same resources.

Conventional network operation systems do not provide solutions to two changes: the change in network configuration from a ring network to a mesh network, and the need for redundancy methods to support a pre-reserved restoration method instead of an OUPSR method.

Therefore, one or more aspects of the present disclosure aim to make it possible to identify a switching path that switches optical paths collectively in a mesh network using a pre-reservation restoration method.

An operation device according to one aspect of the present disclosure is characterized in that it includes: a storage unit that stores network configuration information indicating the connection relationship between a plurality of network elements included in a mesh network and a plurality of links connecting the plurality of network elements; pre-booked restoration route information indicating a pre-booked restoration route that is a detour route that is preset for each path formed in the mesh network; resource information indicating resources available in the mesh network and resources allocated for use in the mesh network; a path management unit that refers to the network configuration information to identify a plurality of paths that pass through a link to be detoured among the plurality of links as a plurality of transit paths, and refers to the pre-booked restoration route information to identify a candidate route that is the pre-booked restoration route that is preset for the plurality of transit paths; a resource management unit that refers to the resource information to determine whether the resource can be assigned to the candidate route; and a route selection unit that selects the candidate route to which the resource can be assigned as a switching path for each of the plurality of transit paths.

A program according to one aspect of the present disclosure causes a computer to function as: network configuration information indicating the connection relationship between a plurality of network elements included in a mesh network and a plurality of links connecting the plurality of network elements; pre-booked restoration route information indicating a pre-booked restoration route that is a detour route that is preset for each path formed in the mesh network; a storage unit that stores resource information indicating resources available in the mesh network and resources allocated for use in the mesh network; a path management unit that refers to the network configuration information to identify a plurality of paths that pass through a link to be detoured among the plurality of links as a plurality of transit paths, and refers to the pre-booked restoration route information to identify a candidate route that is the pre-booked restoration route that is preset for the plurality of transit paths; a resource management unit that refers to the resource information to determine whether the resource can be assigned to the candidate route; and a route selection unit that selects the candidate route to which the resource can be assigned as a switching path for each of the plurality of transit paths.

An operation method according to one aspect of the present disclosure is characterized in that a path management unit refers to network configuration information indicating the connection relationship between a plurality of network elements included in a mesh network and a plurality of links connecting the plurality of network elements, thereby identifying a plurality of paths passing through a link to be detouring among the plurality of links as a plurality of transit paths, the path management unit refers to pre-booked restoration route information indicating a pre-booked restoration route that is a pre-booked detouring route for each path formed in the mesh network, thereby identifying a candidate route that is the pre-booked restoration route that is pre-booked for the plurality of transit paths, a resource management unit refers to resource information indicating resources available in the mesh network and resources allocated for use in the mesh network, thereby determining whether the resources can be allocated to the candidate route, and a route selection unit selects the candidate route to which the resources can be allocated as a switching path for each of the plurality of transit paths.

According to one or more aspects of the present disclosure, in a mesh network, a pre-reservation restoration method can be used to identify a switching path that switches optical paths collectively.

1 is a block diagram illustrating a schematic configuration of an optical communication management system according to first and second embodiments. FIG. 2 is a block diagram showing a schematic configuration of a terminal. 1A and 1B are block diagrams showing an example of a hardware configuration. FIG. 2 is a block diagram illustrating a schematic configuration of an operation device according to the first and second embodiments. 10 is a sequence diagram showing the operation of performing collective switching of optical communication networks by a terminal and an operation device in the first embodiment. FIG. FIG. 13 is a schematic diagram showing an example of an expected result screen image. 10 is a schematic flow diagram for explaining a switching path distribution operation by a route selection unit in the first embodiment. FIG. FIG. 11 is a schematic flow diagram for explaining a switching path distribution operation by a route selection unit in the second embodiment.

Embodiment 1.
FIG. 1 is a block diagram illustrating a schematic configuration of an optical communication management system 100 according to the first embodiment.
The optical communication management system 100 is a system for managing an optical communication network including a plurality of network elements 101 and a plurality of links 102 connecting the plurality of network elements 101 .
The network element 101 is also called a node. The optical communication network is assumed to be a mesh network, which is a mesh-type network.

The optical communication management system 100 includes a terminal 110 and an operation device 120, and may include an optical communication network.
The terminal 110 and the operation device 120 are connected to a network 103 serving as a monitoring network, and a network element 101 of an optical communication network is also connected to the network 103 .

FIG. 2 is a block diagram showing a schematic configuration of the terminal 110. As shown in FIG.
The terminal 110 includes a memory unit 111 , an input unit 112 , a display unit 113 , a communication unit 114 , and a control unit 115 .

The storage unit 111 stores information and programs necessary for processing in the terminal 110 .
The input unit 112 accepts input from an operator of the optical communication management system 100. For example, the input unit 112 accepts input of a link that needs to be bypassed due to the occurrence of a failure, the need for maintenance, the introduction of a new network element, or the like, in other words, a selection of links to be switched collectively.

The display unit 113 displays various screen images. For example, the display unit 113 displays an expected result screen image, which will be described later. The input unit 112 accepts input of a switching instruction selection, which will be described later, via this expected result screen image.

The communication unit 114 communicates with the network 103. For example, the communication unit 114 transmits to the operation device 120 a switching assumed result request instruction including selected link information, which is information indicating the selected link. The communication unit 114 also receives assumed result screen information, which will be described later, from the operation device 120. Furthermore, the communication unit 114 transmits to the operation device 120 a switching instruction selected based on the assumed result screen information.

The control unit 115 controls processing in the terminal 110. For example, the control unit 115 generates selected link information indicating a link selected via the input unit 112, and causes the communication unit 114 to transmit a switching expected result request instruction including the selected link information to the operation device 120. The control unit 115 also receives expected result screen information from the communication unit 114, and causes the display unit 113 to display an expected result screen image based on the expected result screen information. Furthermore, the control unit 115 causes the communication unit 114 to transmit a switching instruction selected by the input unit 112 to the operation device 120.

A part or all of the control unit 115 described above can be configured, for example, as shown in FIG. 3(A), with a memory 10 and a processor 11 such as a CPU (Central Processing Unit) that executes a program stored in the memory 10. Such a program may be provided over a network, or may be provided by being recorded on a recording medium. That is, such a program may be provided, for example, as a program product. In other words, the terminal 110 can be realized by a computer.

In addition, a part or the whole of the control unit 115 can be configured with a processing circuit 12 such as a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), or an FPGA (Field Programmable Gate Array), as shown in FIG. 3B.
As described above, the control unit 115 can be configured with a processing circuit network.

The storage unit 111 can be realized by a storage device such as a volatile memory, a non-volatile memory, a hard disk drive (HDD), or a solid state drive (SSD).
The input unit 112 can be realized by an input device such as a keyboard or a mouse.
The display unit 113 can be realized by a display using a liquid crystal or the like.
The communication unit 114 can be realized by a communication device such as a NIC (Network Interface Card).

FIG. 4 is a block diagram showing a schematic configuration of the operation device 120. As shown in FIG.
The operation device 120 includes a storage unit 121 , a communication unit 126 , and a control unit 127 .

The storage unit 121 stores information and programs necessary for processing by the operation device 120. Programs necessary for processing by the operation device 120 are not shown in FIG.
For example, the storage unit 121 stores network configuration information 122 , advance reservation restoration route information 123 , and resource information 124 .

The network configuration information 122 indicates the configuration of the optical communication network. For example, the network configuration information 122 indicates the connection relationship between multiple network elements 101 included in the optical communication network, which is a mesh network, and multiple links 102 connecting the multiple network elements 101. Specifically, the network configuration information 122 indicates the node routes and links, with the network elements 101 as nodes. In more detail, the network configuration information 122 includes information such as "route #1 of node #1 and route #2 of node #2 are connected by OTS (Optical Transmission Section) link #1."

The pre-booked restoration route information 123 indicates a pre-booked restoration route, which is a detour route that is preset for each path in the optical communication network. It is assumed that a priority is set in advance for the pre-booked restoration route. Here, positive integers starting from "1" are assigned as priorities to the pre-booked restoration routes, with "1" being the highest priority.

The resource information 124 indicates resources available for use in the optical communication network and resources allocated for use in the optical communication network. For example, the resource information 124 indicates, for each link of the optical communication network, the resources that can be allocated and the resources that have actually been allocated. The resources in this case are wavelengths.

The communication unit 126 communicates with the network 103. For example, the communication unit 126 receives a switching assumed result request instruction from the terminal 110. The communication unit 126 also transmits assumed result screen information, which will be described later, to the terminal 110. Furthermore, the communication unit 126 transmits and receives switching instructions.

The control unit 127 controls the processing in the operation device 120 .
For example, the control unit 127 includes a request processing unit 128 , a path management unit 129 , a route selection unit 130 , and a resource management unit 131 .

The request processing unit 128 receives the switching assumption result request instruction received by the communication unit 126, and controls the process of performing a bulk path switching to bypass the selected link indicated by the selected link information included in the switching assumption result request instruction.
For example, the request processing unit 128 notifies the path management unit 129 of the link indicated by the selected link information. As described below, the request processing unit 128 receives from the route selection unit 130 an assumed result for performing collective path switching to bypass the selected link, and generates assumed result screen information indicating the assumed result. The request processing unit 128 then causes the communication unit 126 to transmit the assumed result screen information to the terminal 110.

In addition, the request processing unit 128 receives the switching instruction received by the communication unit 126 and notifies the route selection unit 130 of the switching instruction.

The path management unit 129 receives notification of a link from the request processing unit 128, and identifies all paths that pass through that link by referring to the network configuration information 122. The paths identified here are also called transit paths, since they are paths that pass through the link to be detouring.

The path management unit 129 also refers to the pre-reserved restoration route information 123 to identify all pre-reserved restoration routes for bypassing the link in the transit path. The pre-reserved restoration routes identified here are also called candidate routes. The path management unit 129 then notifies the route selection unit 130 of the paths identified as transit paths and the pre-reserved restoration routes identified as candidate routes.

Furthermore, when the path management unit 129 receives a switching instruction from the route selection unit 130 , it transmits the switching instruction to the network element 101 via the communication unit 126 .
As described below, the path management unit 129 sends switching instructions to multiple network elements 101 via the communication unit 126 to switch to switching paths corresponding to all priorities or to switch to switching paths corresponding to a selected priority, depending on the operator's selection.

The route selection unit 130 selects a candidate route to which resources can be allocated as a switching path for each of the multiple transit paths. For example, the route selection unit 130 allocates the pre-booked restoration routes by priority by inquiring of the resource management unit 131 about the availability of resources for each path notified by the path management unit 129, in descending order of the priority of the pre-booked restoration route. The route selection unit 130 then notifies the request processing unit 128 of the expected result indicating the allocated pre-booked restoration route. Here, the allocated pre-booked restoration route becomes the switching path.

In addition, when the route selection unit 130 receives a switching instruction from the request processing unit 128, it notifies the path management unit 129 of the switching instruction.

The resource management unit 131 refers to the resource information 124 to determine whether resources can be allocated to the pre-booked restoration route, which is a candidate route. For example, the resource management unit 131 refers to the resource information 124 to determine whether there are available resources for all links included in the pre-booked restoration inquired about by the route selection unit 130. The resource management unit 131 notifies the route selection unit 130 of the result of the determination, and stores the secured resources in the resource information 124 as allocated resources in response to an instruction from the route selection unit 130.

A part or all of the control unit 127 described above can be configured, for example, as shown in FIG. 3(A), by a memory 10 and a processor 11 such as a CPU that executes a program stored in the memory 10. Such a program may be provided over a network, or may be provided by being recorded on a recording medium. That is, such a program may be provided, for example, as a program product. In other words, the operation device 120 can be realized by a computer.

In addition, a part or the whole of the control unit 127 may be configured by a processing circuit 12 such as a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC, or an FPGA, as shown in FIG. 3(B).
As described above, the control unit 127 can be configured with a processing circuit network.

The storage unit 121 can be realized by a storage device such as a volatile memory, a non-volatile memory, a HDD, or an SSD.
The communication unit 126 can be realized by a communication device such as a NIC.

FIG. 5 is a sequence diagram showing the operation of the terminal 110 and the operation device 120 in the first embodiment for performing collective switching of the optical communication network.
First, the operator selects links to be collectively switched using the input unit 112 of the terminal 110. The control unit 115 of the terminal 110 generates selected link information indicating the selected links, and causes the communication unit 114 to transmit a switching assumption result request instruction including the selected link information to the operation device 120 (S10).

The communication unit 126 of the operation device 120 receives the switching assumption result request instruction and provides the switching assumption result request instruction to the request processing unit 128. The request processing unit 128 provides a path list transmission instruction to the path management unit 129 that includes the link indicated by the selected link information included in the switching assumption result request instruction (S11).

The path management unit 129 references the network configuration information 122 to generate a path list indicating all paths that use the links included in the path list transmission instruction. The path management unit 129 also references the advance reservation restoration route information 123 to identify all advance reservation restoration routes that bypass the links for each of all paths included in the path list. The path management unit 129 then provides the path list and the identified advance reservation restoration routes to the route selection unit 130 (S12).

The route selection unit 130 identifies one pre-reserved restoration route for each path included in the path list, starting with the pre-reserved restoration route with the highest priority, and queries the resource management unit 131 as to whether or not there are available resources in all the links included in that one pre-reserved restoration route (S13).

The resource management unit 131 refers to the resource information 124 to determine whether or not there are available resources for all links included in the one pre-reserved restoration route for which an inquiry has been received, and responds to the route selection unit 130 with the result of that determination as the resource status (S14).

If, based on the resource status from the resource management unit 131, all links included in the one advance reservation restoration route queried have available resources, the route selection unit 130 instructs the resource management unit 131 to secure those resources (S15). Upon receiving such an instruction, the resource management unit 131 allocates resources to all links included in that one self-recommended reservation restoration route, and stores the resource allocation status in the resource information 124.

By repeating the process of steps S13 to S15, the route selection unit 130 generates an assumed result for all paths included in the path list, which determines whether or not the pre-booked restoration route can be switched, and if so, identifies the pre-booked restoration route that can be switched to. The route selection unit 130 then provides the assumed result to the request processing unit 128 (S16).

When the request processing unit 128 receives the expected result from the route selection unit 130, it generates expected result screen information for displaying the expected result, and causes the communication unit 126 to transmit the expected result screen information to the terminal 110 (S17).

The control unit 115 of the terminal 110 receives the expected result screen information received by the communication unit 114, and displays the expected result screen image on the display unit 113 based on the expected result screen information.

FIG. 6 is a schematic diagram showing an example of an expected result screen image.
The assumed result screen image 140 shown in FIG. 6 includes an all-priority collective switching button 141, collective switching buttons for each priority 142-1 to 142-N, a switchable path display area 143, and a switch-setting no-path display area 144.

In addition, for the priority-based collective switching buttons 142-1 to 142-N, the non-switchable path display area 143, and the non-switchable path display area 144, there are provided columns corresponding to a switching path priority column 145, a path start point column 146, a path end point column 147, a pre-switching path details column 148, and a post-switching path details column 149.

The column corresponding to the switching path priority column 145 for each of the priority-based collective switching buttons 142-1 to 142-N shows the priority of the pre-booked restoration route that is switched by the priority-based collective switching buttons 142-1 to 142-N.

In the columns corresponding to the path start point column 146 in each of the priority-specific collective switching buttons 142-1 to 142-N, the non-switchable path display area 143, and the non-switchable path display area 144, identification information is displayed to identify the network element 101 that is the start point of the path corresponding to each of the priority-specific collective switching buttons 142-1 to 142-N, the non-switchable path display area 143, and the non-switchable path display area 144. The identification information here is the node name.

In the columns corresponding to the path end point columns 147 in each of the priority-specific collective switching buttons 142-1 to 142-N, the non-switchable path display area 143, and the non-switchable path display area 144, identification information is displayed to identify the network element 101 that is the end point of the path corresponding to each of the priority-specific collective switching buttons 142-1 to 142-N, the non-switchable path display area 143, and the non-switchable path display area 144.

In the columns corresponding to the pre-switching path details column 148 in each of the priority-specific collective switching buttons 142-1 to 142-N, the non-switchable path display area 143, and the switching setting no-path display area 144, there are shown buttons for inputting an instruction to display the detailed configuration of the pre-switching path corresponding to each of the priority-specific collective switching buttons 142-1 to 142-N, the non-switchable path display area 143, and the switching setting no-path display area 144.
For example, when the operator selects any button in the column using the input unit 112 and inputs an instruction to execute the selected button, the detailed configuration of the corresponding path is displayed on the display unit 113 .

In the columns corresponding to the post-switching path details column 149 in each of the collective switching buttons 142-1 to 142-N by priority, the non-switchable path display area 143, and the switching setting no-path display area 144, there are shown buttons for inputting an instruction to display the detailed configuration of the post-switching path corresponding to each of the collective switching buttons 142-1 to 142-N by priority, the non-switchable path display area 143, and the switching setting no-path display area 144.
For example, when the operator selects any button in the column using the input unit 112 and inputs an instruction to execute the selected button, the detailed configuration of the corresponding path is displayed on the display unit 113 .

Returning to FIG. 5, when the operator selects and inputs an instruction to execute the all priorities batch switching button 141 or any of the priority-specific batch switching buttons 142-1 to 142-N on the expected result screen image 140 shown in FIG. 6, the control unit 115 of the terminal 110 generates a switching instruction corresponding to the selected button and has the communication unit 114 transmit the switching instruction to the operation device 120 (S18).

In the operation device 120 that receives such a switching instruction, the request processing unit 128 receives the switching instruction from the communication unit 126 and provides the switching instruction to the route selection unit 130 (S19).

The route selection unit 130 also provides the switching instruction to the path management unit 129 (S20), and the path management unit 129 transmits the switching instruction to the network element 101 corresponding to the communication unit 126 (S21).

The network element 101 that receives such a switching instruction switches the link in accordance with the switching instruction and transmits the switching result to the operation device 120 (S22).

In the operation device 120 that receives such a switching result, the path management unit 129 receives the switching result from the communication unit 126 and provides the switching result to the request processing unit 128 (S23).

The request processing unit 128 causes the communication unit 126 to transmit the switching result to the terminal 110 (S24). In the terminal 110 that receives such a switching result, the control unit 115 causes the display unit 113 to display the switching result. This allows the operator to know that the switching has been performed.

FIG. 7 is a schematic flow diagram for explaining a switching path distribution operation by the route selection unit 130 in the first embodiment.
First, the route selection unit 130 specifies one path included in the path list from the path management unit 129 as a target path (S30).

The route selection unit 130 determines whether the pre-reserved restoration route of the target path is included in the pre-reserved restoration route identified from the path management unit 129 (S31). If the pre-reserved restoration route of the target path is not included, the process proceeds to step S32, and if the pre-reserved restoration route of the target path is included, the process proceeds to step S33.

In step S32, the route selection unit 130 assigns the target path to a path without switching setting.
On the other hand, in step S33, the route selection unit 130 inquires of the resource management unit 131 whether or not there are available resources in all links of the advance reserved restoration route of priority 1 of the target path, thereby determining whether or not the target path can be switched to the advance reserved restoration route of priority 1. The resource management unit 131 determines whether or not there are available resources, for example, from the lowest wavelength number, and responds to the route selection unit 130 with the determination result as the resource status. Here, if there are no available resources, the resource management unit 131 responds with the fact that there are no available resources as the determination result, and if there are available resources, it responds with the resources to be assigned to the advance reserved restoration route as the determination result.

If all links in the pre-reserved restoration route of priority 1 of the target path have available resources, processing proceeds to step S34, and if there are any links in the pre-reserved restoration route of priority 1 of the target path that do not have available resources, processing proceeds to step S35.

In step S34, the route selection unit 130 assigns the advance reserved restoration route with priority 1 of the target path as a switching path with priority 1.
Meanwhile, in step S35, the route selection unit 130 inquires of the resource management unit 131 as to whether or not there are available resources in all links of the advance reserved restoration route of priority 2 of the target path, thereby determining whether or not the target path can be switched to the advance reserved restoration route of priority 2. The resource management unit 131 determines whether or not there are available resources starting from the lowest wavelength number, as in the case of priority 1, and returns the determination result to the route selection unit 130 as the resource status. Then, if there are available resources in all links of the advance reserved restoration route of priority 2 of the target path, the process proceeds to step S36.

In step S36, the route selection unit 130 assigns the advance reserved restoration route with priority level 2 of the target path as a switching path with priority level 2.
Similarly, if no available resources are found, the route selection unit 130 queries the resource management unit 131 as to whether there are any available resources up to the lowest priority N (N is an integer greater than or equal to 1) identified as a pre-reserved restoration route for the target path (S37).

Then, if the resource management unit 131 responds that there are available resources in all links of the pre-booked restoration route of priority N of the target path, the route selection unit 130 assigns the pre-booked restoration route of priority N of the target path as a switching path of priority N (S38).
On the other hand, if the resource manager 131 reports that there is a link with no available resources in the advance reserved restoration route of priority N for the target path, the route selector 130 assigns the target path to an unswitchable path (S39).

Then, the route selection unit 130 repeats the operation shown in FIG. 7 until all paths included in the path list are identified as target paths. This allows allocation of all paths included in the path list.

As described above, according to the first embodiment, collective switching is performed according to the priority selected by the operator.
In addition, paths with no switching setting or paths that cannot be switched can also be switched by the operator by individually re-setting the switching destination.

Embodiment 2.
As shown in FIG. 1, the optical communication management system 200 according to the second embodiment includes a terminal 110 and an operation device 220 .
The terminal 110 of the optical communication management system 200 according to the second embodiment is similar to the terminal 110 of the optical communication management system 100 according to the first embodiment.

As shown in FIG. 4, the operation device 220 in embodiment 2 includes a memory unit 121, a communication unit 126, and a control unit 227.

The memory unit 121 and the communication unit 126 of the operation device 220 in the second embodiment are similar to the memory unit 121 and the communication unit 126 of the operation device 120 in the first embodiment.

The control unit 227 controls the processing in the operation device 220 .
The control unit 227 includes a request processing unit 128 , a path management unit 129 , a route selection unit 230 , and a resource management unit 131 .
The request processing unit 128, path management unit 129 and resource management unit 131 of the control unit 227 in the second embodiment are similar to the request processing unit 128, path management unit 129 and resource management unit 131 of the control unit 127 in the first embodiment.

The route selection unit 230 in the second embodiment performs almost the same processing as the route selection unit 130 in the first embodiment, but differs from the first embodiment in the allocation operation of the pre-booked restoration route.

As described above, in embodiment 1, the route selection unit 130 inquires of the resource management unit 131 as to whether or not resources can be allocated to the candidate routes, starting with the highest priority route, and the resource management unit 131 responds by indicating whether or not resources can be allocated to the candidate routes inquired about.
On the other hand, in the second embodiment, the route selection unit 230 inquires of the resource management unit 131 as to whether or not resources can be allocated to the candidate route, and the resource management unit 131 responds to the route selection unit 230 as to whether or not resources can be allocated to the candidate route. Then, the route selection unit 230 selects, as a switching path, a candidate route to which resources can be allocated, in order from the passing path having the fewest number of candidate routes to which resources can be allocated and in order from the candidate route having the highest priority.
As a result, the route selection unit 230 of the second embodiment increases the number of switchable optical paths compared to the first embodiment.

FIG. 8 is a schematic flow diagram for explaining a switching path distribution operation by the route selection unit 230 in the second embodiment.
First, the route selection unit 230 acquires the path list and the identified advance reserved restoration route from the path management unit 129 (S40).

The route selection unit 230 determines whether or not there is a path in the acquired path list that does not have a pre-booked restoration route (S41).
If the acquired path list contains a path that does not have a pre-booked restoration route, such a path is assigned to the non-switching setting path (S42).

The route selection unit 230 identifies paths in the path list that have a pre-booked restoration route as paths with routes, and checks the number of routes that can be switched at the current time by inquiring of the resource management unit 131 for each path with routes (S43).
If there is a path with a switchable route count of "0" among the route-enabled paths, the route selection unit 230 classifies such a path as a non-switchable path (S44).

The route selection unit 230 checks whether or not there is a path with a route number of "1" that can be switched and a switchable advance reserved restoration route to which priority 1 is assigned (S45).
If there is a path among the route-containing paths in which the number of switchable routes is "1" and the switchable pre-reserved restoration route is assigned priority 1, the route selection unit 230 causes the resource management unit 131 to secure resources for the pre-reserved restoration route of priority 1 of such a path, and allocates the pre-reserved restoration route of priority 1 of such a path to the priority 1 path (S46).

The route selection unit 230 checks whether or not there is a path with a route number of "1" that can be switched to and a switchable advance reserved restoration route to which priority level 2 is assigned (S47).
If there is a path among the route-containing paths in which the number of switchable routes is "1" and the switchable pre-reserved restoration route is assigned priority 2, the route selection unit 230 causes the resource management unit 131 to secure resources for the pre-reserved restoration route of priority 2 of such a path, and allocates the pre-reserved restoration route of priority 2 of such a path to the priority 2 path (S48).

Similarly, the route selection unit 230 checks whether there is a path, up to the lowest priority N (N is an integer greater than or equal to 1), in which the number of switchable routes is "1" and the switchable pre-reserved restoration route is assigned priority N (S49).
If there is a path among the route-containing paths in which the number of switchable routes is "1" and the switchable pre-reserved restoration route is assigned priority N, the route selection unit 230 causes the resource management unit 131 to secure resources for the pre-reserved restoration route of priority N of such a path, and allocates the pre-reserved restoration route of priority N of such a path to the priority N path (S50).

The route selection unit 230 assigns the remaining paths among the paths with routes that have a switchable route count of "1" to non-switchable paths (S51).

Then, the route selection unit 230 checks the current number of switchable routes by inquiring again of the resource management unit 131 about unassigned paths, which are paths that have not been assigned among the routed paths (S52).
If there is a path with the number of switchable routes of "0" among the unassigned paths, the route selection unit 230 assigns such a path to an unswitchable path (S53).

If there is a path with a switchable route count of "1" among the unassigned paths, the route selection unit 230 returns the process to step S45 and again assigns the path with a route count of "1" according to priority.

On the other hand, if there is no path with a switchable route count of "1" among the unassigned paths, the route selection unit 230 proceeds to step S54.
In step S54, the route selection unit 230 checks whether or not there is a path, among the unassigned paths, for which the number of switchable routes is "2" and for which priority level 1 is assigned to the switchable advance reserved restoration route.
If there is a path among the unassigned paths for which the number of switchable routes is "2" and the switchable pre-reserved restoration route is assigned priority 1, the route selection unit 230 causes the resource management unit 131 to secure resources for the pre-reserved restoration route of priority 1 for such a path, and assigns the pre-reserved restoration route of priority 1 for such a path to the priority 1 path (S55).

Similarly, the route selection unit 230 performs allocation according to priority up to M (M is an integer equal to or greater than 1), which is the maximum number of switchable routes.
Then, the route selection unit 230 checks whether or not there is a path, among the unassigned paths, for which the number of switchable routes is "M" and for which a switchable advance reserved restoration route is assigned priority level N (S56).
If there is a path among the unassigned paths for which the number of switchable routes is "M" and the switchable pre-reserved restoration route is assigned priority N, the route selection unit 230 causes the resource management unit 131 to secure resources for the pre-reserved restoration route of priority N for such a path, and assigns the pre-reserved restoration route of priority N for such a path to the priority N path (S57).
Then, if there are still unassigned paths remaining, the route selection unit 230 assigns such paths to non-switchable paths (S58).

As described above, according to the second embodiment, for paths with few switching routes, resources are secured on a priority basis even if the route to which the switch is made has a low priority, so that the number of paths that can be switched can be increased.

100, 200 Optical communication management system, 101 Network element, 102 Link, 110 Terminal, 111 Storage unit, 112 Input unit, 113 Display unit, 114 Communication unit, 115 Control unit, 120, 220 Operation device, 121 Storage unit, 122 Network configuration information, 123 Advance reservation restoration route information, 124 Resource information, 126 Communication unit, 127, 227 Control unit, 128 Request processing unit, 129 Path management unit, 130, 230 Route selection unit, 131 Resource management unit.

Claims (6)

a storage unit that stores network configuration information indicating a connection relationship between a plurality of network elements included in a mesh network and a plurality of links connecting the plurality of network elements; advance reservation restoration route information indicating an advance reservation restoration route which is a detour route that is preset for each path formed in the mesh network; and resource information indicating resources available in the mesh network and resources allocated for use in the mesh network;
a path management unit that identifies, as a plurality of transit paths, a plurality of paths that pass through a link to be detouring among the plurality of links by referring to the network configuration information, and that identifies, by referring to the advance reserved restoration route information, candidate routes that are the advance reserved restoration routes that are preset for the plurality of transit paths;
a resource management unit that determines whether or not the resources can be allocated to the candidate routes by referring to the resource information;
a route selection unit that selects, as a switching path, the candidate route to which the resource can be allocated for each of the plurality of passing paths. In the advance reservation restoration route information, a priority is assigned to the advance reservation restoration route,
the route selection unit inquires of the resource management unit whether or not the resources can be allocated to the candidate routes in descending order of priority;
The operation device according to claim 1 , wherein the resource management unit responds to the route selection unit as to whether or not the resource can be allocated to the candidate route inquired about. In the advance reservation restoration route information, a priority is assigned to the advance reservation restoration route,
2. The operation device according to claim 1, wherein the route selection unit selects, as the switching path, a candidate route to which the resources can be allocated, in order from the passing path having the fewest number of candidate routes to which the resources can be allocated and in order from the candidate route having the highest priority. A communication unit that communicates with the plurality of network elements,
4. The operation device according to claim 2 or 3, wherein the path management unit instructs the plurality of network elements via the communication unit to switch to the switching paths corresponding to all of the priorities or to switch to the switching path corresponding to a selected priority, depending on an operator's selection. Computer,
a storage unit that stores network configuration information indicating a connection relationship between a plurality of network elements included in a mesh network and a plurality of links connecting the plurality of network elements; advance reservation restoration route information indicating an advance reservation restoration route which is a detour route previously set for each path formed in the mesh network; and resource information indicating resources available in the mesh network and resources allocated for use in the mesh network;
a path management unit that, by referring to the network configuration information, identifies a plurality of paths passing through a link to be detouring among the plurality of links as a plurality of passing paths, and, by referring to the advance reserved restoration route information, identifies candidate routes that are the advance reserved restoration routes that are preset for the plurality of passing paths;
a resource management unit that determines whether or not the resources can be allocated to the candidate route by referring to the resource information; and
a route selection unit that selects, as a switching path, the candidate route to which the resource can be allocated for each of the plurality of passing paths. The path management unit refers to network configuration information indicating a connection relationship between a plurality of network elements included in the mesh network and a plurality of links connecting the plurality of network elements, and identifies a plurality of paths passing through a link to be detouring among the plurality of links as a plurality of passing paths;
the path management unit refers to advance reservation restoration route information indicating an advance reservation restoration route which is a detour route which is preset for each path formed in the mesh network, thereby identifying a candidate route which is the advance reservation restoration route which is preset for the plurality of passing paths;
A resource management unit determines whether or not resources can be allocated to the candidate route by referring to resource information indicating resources available in the mesh network and resources allocated for use in the mesh network;
a route selection unit selecting, as a switching path, the candidate route to which the resources can be allocated for each of the plurality of passing paths.

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