JP5419740B2 - Pass accommodation design method - Google Patents

Description

  The present invention relates to a path accommodation design method in a multi-ring network provided with a plurality of ring networks in which a plurality of node devices are connected in a ring shape.

  In a communication network composed of a plurality of node devices connected by a physical transmission line such as an optical fiber, a logical for performing signal transmission between the node device as the start point and the node device as the end point. A correct path is set.

  In a communication network, at least two routes, such as an active system and a standby system, are provided as paths connecting a plurality of node devices through which paths pass. In order to avoid the occurrence of a failure in both the active and standby transmission lines, it is desirable to set the two paths so that the transmission lines (links) do not overlap each other. Hereinafter, the two routes are referred to as a first route and a second route.

  In recent years, a multi-ring network in which a plurality of ring networks are connected to each other is used to configure a large-scale relay network or the like. Here, Patent Literature 1 and Patent Literature 2 describe that the first route and the second route of a path in a multi-ring network are designed so as not to overlap each other. Non-Patent Document 1 describes various configuration examples of a multi-ring network.

JP-A-10-224389 Japanese Patent Laid-Open No. 10-79757

J. Wang et al., "Multiring Techniques for Scalable Battlespace Group Communications", IEEE Com. Mag., November, 2005. H. Zang, et al., "A Review of Routing and Wavelength Assignment Approaches for Wavelength-Routed Optical WDM Networks", OPTICAL NETWORKS MAGAZINE, Vol. 47-60, January 2000. Y. Huang, JP Heritage, and B. Mukherjee, "Connection provisioning with transmission impairment consideration in optical WDM networks with high-speed channels," IEEE J. Lightw. Technol., Vol. 23, No. 3, pp. 982- 993, March 2005. "Transmission media and optical systems characteristics-Characteristics of optical systems," ITU-T Recommendation G.680.

  As examples of the configuration of the multi-ring network, there are a Hierarchical network as shown in FIG. 23 and an HSHR (Hierarchical Self-Healing Ring) network as shown in FIG.

  In the Hierarchical network shown in FIG. 23, when the first route and the second route are designed so as not to overlap each other based on the Dijkstra algorithm or the like capable of searching for the shortest route, the first route and the second route in each ring. There are not always two paths, and the two paths are distributed over the entire communication network, which may cause difficulties in the maintenance and management of the network.

  In addition, in the HSHR network shown in FIG. 24, when designing two routes by the shortest route search, depending on the node pair of the demand generation path, the distance between the first route and the second route is within the transmission constraint. In some cases, it may be necessary to arrange a regenerative repeater. In addition, there may be a large difference between the route lengths of the first route and the second route, and transmission delay may be increased.

  The present invention has been made in view of the above points, and determines two paths of a path in a multi-ring network without distributing the two paths and without causing a large difference between the two path lengths. It aims at providing the technology to do.

  In order to solve the above-described problems, the present invention provides path accommodation having a function of determining a path of a path set on a multi-ring network including a plurality of rings in which a plurality of node devices are connected in a ring shape. A path accommodation design method executed by a design device, which is configured to pass through a ring through which the path passes by receiving input of information indicating a start point node and information indicating an end point node of a path whose path is to be determined A passing ring network determining step for determining a ring network; and a path route determining step for searching for a path of the path within the range of the passing ring network determined by the passing ring network determining step. It is constituted as a path accommodation design method.

  In addition, the present invention provides path accommodation executed by a path accommodation design apparatus having a function of determining a path of a path set on a multi-ring network including a plurality of rings in which a plurality of node devices are connected in a ring shape. In the design method, the path of the path is two paths of a first path and a second path, the first path is searched by a full path search, and the second path is determined as the first path. Determining a route that does not overlap with the first route, a difference in the number of hops between the first route and the second route in the combination group of the first route and the second route obtained by the search, and the first route Determining a combination of the first route and the second route that minimizes one or both of the difference between the first route and the second route distance as the two routes of the path. A path accommodation design method characterized by Configuration may be.

  In addition, the present invention provides path accommodation executed by a path accommodation design apparatus having a function of determining a path of a path set on a multi-ring network including a plurality of rings in which a plurality of node devices are connected in a ring shape. In the design method, the path of the path is two paths of a first path and a second path, and between the start point node of the path and an inter-ring connection point node on the ring to which the start point node belongs. From the start node to the end node, select the longest path and the shortest path that connect the inter-ring connection point nodes alternately in each ring to the ring to which the end node belongs. Determining the first route, and determining as the second route a route that does not overlap the first route in the reverse direction in each ring. It may be configured as a path accommodation design method.

  In addition, the present invention provides path accommodation executed by a path accommodation design apparatus having a function of determining a path of a path set on a multi-ring network including a plurality of rings in which a plurality of node devices are connected in a ring shape. In the design method, the path of the path is two paths of a first path and a second path, and between the start point node of the path and an inter-ring connection point node on the ring to which the start point node belongs. From the start node to the end node, select the shortest path and the longest path that connect the inter-ring connection point nodes alternately in each ring up to the ring to which the end node belongs. Determining the first route, and determining as the second route a route that does not overlap the first route in the reverse direction in each ring. It may be configured as a path accommodation design method.

  According to the present invention, even in a complex-shaped multi-ring network, a housing design in which the first route and the second route are closed in each ring is possible. This reduces the number of search paths and reduces the difficulty of maintenance and operation. This effect increases as the multi-ring network becomes more complex. In addition, it becomes possible to reduce the path length difference between the first path and the second path, thereby reducing the case where only one path can be designed for transmission. Therefore, it is not necessary to install an extra regenerative repeater, so that the equipment cost can be reduced.

It is a functional lineblock diagram of path accommodation design device 1 in an embodiment of the invention. It is a figure which shows the structure of a multi-ring network. It is a figure which shows the structure of a multi-ring network. It is a figure which shows the example of the table information stored in the connection information storage part 17 between nodes. It is a figure which shows the example of the table information stored in the connection information storage part 16 between rings. It is a flowchart which shows the process sequence in 1st Embodiment. It is a figure which shows the example of the resource information stored in the resource information storage part. 6 is a diagram illustrating an example of information stored in a node number information storage unit 19. FIG. It is a flowchart which shows another processing procedure in 1st Embodiment. It is a figure which shows the path | route of the ring selected in 1st Embodiment. It is a figure which shows the information stored in the internode connection information storage part 17 after deleting some internode connection relations. It is a figure which shows the physical topology of the connection between rings. It is a figure which shows the physical topology of the connection between nodes. It is a flowchart which shows the process sequence in 2nd Embodiment. It is a figure which shows the example of the table information stored in the connection information storage part 17 between nodes in 2nd Embodiment. It is a figure which shows the 1st path | route and 2nd path | route determined in 2nd Embodiment. It is a flowchart which shows the process sequence in 3rd Embodiment. It is a flowchart which shows the process sequence in 4th and 5th embodiment. It is a flowchart which shows the process sequence in 6th Embodiment. It is a flowchart which shows the process sequence in 7th Embodiment. It is a figure which shows the example of the network structure applied in 9th-12th embodiment. It is a figure which shows the example of the network structure applied in 9th-12th embodiment. It is a figure for demonstrating the problem of a prior art. It is a figure for demonstrating the problem of a prior art.

  In describing the embodiment of the present invention, the term “path” will be described first. A “path” in the present specification and claims is a logical transmission line set on a physical transmission line medium such as an optical fiber, and includes a node device serving as a start point and a node device serving as an end point. This is a signal transmission line connecting the two. In the embodiment of the present invention, it is assumed that a wavelength path is used as a path. However, it goes without saying that the present invention is not limited to a wavelength path but can be applied to other types of paths. Examples of such a path include a TDM path, an Ethernet (registered trademark) path, an MPLS Label Switched Path, a VCAT (Virtual Concatenation) in which these are grouped, a Link Aggregation, and the like.

  Embodiments of the present invention will be described below with reference to the drawings. The following first to eighth embodiments of the present invention are suitable for application to a multi-ring network in which rings expand vertically and horizontally like the Hierarchical network shown in FIG. 23. Embodiments of the present invention Nos. 9 to 12 are suitable for application to a multi-ring network in which a plurality of rings are connected to one ring, such as the HSHR network shown in FIG.

[Device configuration]
First, the path accommodation design apparatus 1 in the embodiment of the present invention will be described. In FIG. 1, the functional block diagram of the path | pass accommodation design apparatus 1 is shown. As shown in FIG. 1, the path accommodation design apparatus 1 includes an input / output unit 11, a path passing ring network determination unit 12, a path route determination unit 13, a wavelength design unit 14, a path control unit 15, and an inter-ring connection information storage unit 16. , An inter-node connection information storage unit 17, a resource information storage unit 18, a node number information storage unit 19, and a wavelength information storage unit 20. Hereinafter, an outline of each functional unit will be described.

  The input / output unit 11 is a functional unit that inputs information from the outside into the path accommodation design apparatus 1 and outputs information (calculation results, control information, etc.) from the path accommodation design apparatus 1 to the outside. A functional unit including an interface and a communication function for performing data communication with a communication network.

  The path passing ring network determination unit 12 receives input of the start node and the end node of the design target path, and determines a passing ring network (ring connection route) configured by a ring group through which the path route passes. Have The path route determination unit 13 has a function of determining a path route (route of a routed node) that connects a start point node and an end point node of the design target path. The wavelength design unit 14 has a function of assigning a wavelength used by the path in the determined route. For example, the path control unit 15 has a function of securing and setting a wavelength so that a signal can be transmitted to each node device on the path. Each information storage unit will be described in each embodiment described below.

  The path accommodation design apparatus 1 is used in the following embodiments. However, not all the functional units described above are required, and it is sufficient if functional units necessary for the processing of each embodiment are provided. For example, when the path accommodation design apparatus 1 performs only path design and the actual setting control of the path is performed by another apparatus, the path control unit 15 is unnecessary.

  The path accommodation design apparatus 1 may be an apparatus that is provided outside the multi-ring network that performs signal transmission and can communicate with each transmission apparatus (node apparatus) on the control network. A device that is not connected to the multi-ring network may be used. Further, the path accommodation design device 1 may be a device incorporated in a node device.

The path accommodation design apparatus 1 can be realized by hardware such as a logic circuit, or can be realized by installing a program corresponding to the processing described in each embodiment in a computer apparatus including a CPU and a memory. You can also. The computer device may be a server or the like, or a control device in the transmission device. The program may be installed in a computer device from a recording medium such as a portable memory, or may be downloaded from a server on a network and installed in the computer device.
[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described. 2 and 3 show the configuration of a multi-ring network used as an example in the present embodiment. FIG. 2 shows only the inter-ring connection relationship, and FIG. 3 shows each node in each ring.

  As shown in FIGS. 2 and 3, the number of rings in the multi-ring network is 6, and the number of nodes in each ring is 5.

  In the present embodiment, a number for identifying the ring is assigned to each ring. In the example of FIG. 2, numbers 1 to 6 are assigned to the respective rings.

  In addition, each node constituting the ring is assigned a number including the ring number. In the example shown in FIG. 3, a 2-digit number is assigned to each node, and among the 2 digits, the first digit is the ring number and the second digit is the node number in the ring. In this example, a 2-digit number is assigned, but of course, the number of digits varies depending on the number of rings and the number of rings in one node. For example, when the number of nodes in the ring is two or more digits, the node number is a three or more digit number.

  In the example illustrated in FIG. 3, for example, a node having a node number of 15 (may be described as “node 15”) is a node number in a ring having a ring number of 1 (may be expressed as “ring 1”). Indicates 5 nodes.

  Two ring numbers and node numbers are assigned at the connection points of the rings. For example, 2335 represents a boundary node between a ring with a ring number of 2 and a node with a ring number of 3. These numbering makes it possible to identify the correspondence between nodes and rings. In this embodiment, a number is used as identification information for identifying a node or a ring. However, it is not essential to use a number as identification information, and any number can be used as long as information can be distinguished. Identification information may be used.

  The internode connection information storage unit 17 in the path accommodation design apparatus 1 stores table information indicating the connection relation between the nodes numbered as described above. FIG. 4 shows an example of table information stored in the internode connection information storage unit 17.

  The example shown in FIG. 4 uses an adjacent list format in which the numbers of nodes adjacent to the node are recorded in association with the numbers of the nodes. In the example of FIG. 4, “−1” indicates that there is no node to be connected. For example, in the example of FIG. 4, the numbers 15 and 1225 of each node adjacent to the node 11 are recorded in association with 11 as shown in the configuration of FIG.

  Further, the inter-ring connection information storage unit 16 in the path accommodation design apparatus 1 stores table information representing the connection relationship between the rings numbered as described above. FIG. 5 shows an example of table information stored in the inter-ring connection information storage unit 16.

  In the example shown in FIG. 5 as well, as in the case of inter-node connection, an adjacent list format in which the numbers of the rings adjacent to the ring are recorded in association with the numbers of the respective rings is used. In the example of FIG. 5, “−1” indicates that there is no ring to be connected. For example, in the example of FIG. 5, the numbers 2 and 4 of each ring adjacent to the ring 1 are recorded in association with 1 as in the configuration shown in FIG.

  Next, the flow of the path accommodation design process executed by the path accommodation design apparatus 1 will be described with reference to the flowchart of FIG.

  First, for example, an operator receives a path accommodation design request including information for specifying a start node and an end node of a design target path from a client or the like, and inputs a start node number and an end node number to the path accommodation design apparatus 1. (Step 0). Here, it is assumed that the start node is number 15 and the end node is number 63.

  The path passing ring network determination unit 12 that has received the start node number and the end node number from the input / output unit 11 first extracts the start point ring and the end point ring (step 1). Here, the path passing ring network determination unit 12 extracts the first digit 1 from the start node number 15 as the start ring number, and the first digit 6 from the end node number 63 to the end ring number. Extract as

  In the above example, both the start node and the end node are not ring-to-ring connection points. If either or both of the start node and the end node are ring-to-ring connection points, a plurality of rings adjacent to the node are set as start (or end) rings, and a shortest path search described below is performed to perform a passing ring. Find the net.

  For example, in FIG. 3, if 1341 is the start point node and 3461 is the end point node, the path passing ring network determination unit 12 extracts ring 1 and ring 4 as the start point ring from the node number, and the end point Ring 3 and ring 6 are extracted as rings, and a shortest path search is performed in each of the sections of ring 1-ring 3, ring 1-ring 6, ring 4-ring 3, and ring 4-ring 6. In this case, a plurality of routes are always selected in the route search step.

  Subsequently, the path passing ring network determination unit 12 searches for the shortest path between the rings from the start point ring to the end point ring by using the information stored in the inter-ring connection information storage unit 16 (FIG. 5) (step 2). ). For the shortest path search, for example, a Dijkstra algorithm is used.

  In this embodiment, as a result of performing the shortest path search, 1-2-3-6 as the first path (inter-ring connection path), 1-4-5-6 as the second path, Three shortest paths 1-2-5-6 are detected as paths. More specifically, the rings 2 and 4 connected to the ring 1 are extracted, and the ring 2 and the ring 4 are searched for the connected ring until the ring 6 is found. Is detected.

  Subsequently, the path passing ring network determination unit 12 determines whether or not a plurality of routes are detected as a result of the shortest route search (step 3). As a result of the determination in step 3, if a plurality of routes are not detected, the process proceeds to step 5, and if a plurality of routes is detected, the process proceeds to step 4.

  In step 4, the path passing ring network determination unit 12 performs a process of selecting one route from the plurality of routes detected in step 2. In the present embodiment, the path passing ring network determination unit 12 refers to the resource information stored in the resource information storage unit 18 and selects one route based on the resource information.

  FIG. 7 shows an example of resource information stored in the resource information storage unit 18. In the example illustrated in FIG. 7, the resource information is information in which the number of free wavelengths (resources) that are not used in the ring is recorded for each ring.

  In step 4, the path passing ring network determination unit 12 calculates the total of free resources of the ring on the route for each of a plurality of routes using the resource information shown in FIG. 7, and selects the route having the largest total. To do.

  In the example of FIG. 7, the first route (1-2-3-6) has a total of 65 free wavelengths, the second route (1-4-5-6) has 80, the third route (1 Since -2-5-6) is calculated as 75, the second route 1-4-5-6 with the most free resources is selected, and the process proceeds to Step 5. Note that the above method is merely an example of a method for selecting one route from a plurality of routes, and various other methods can be used.

  For example, in the examples of FIGS. 2 and 3, the number of nodes in the ring is the same in all rings, but when the number of nodes in each ring can be different, the number of nodes in each ring is stored. With reference to the node number information storage unit 19, it is also possible to select a route with the minimum number of nodes from a plurality of routes.

  FIG. 8 shows an example of information stored in the node number information storage unit 19. In the example of FIG. 8, the first route (1-2-3-6) has a total of 34 nodes per ring, the second route (1-4-5-6) has 39, and the third route. Since (1-2-5-6) is calculated as 37, the first path 1-2-3-6 with the smallest number of nodes is selected.

  Further, by using both the information stored in the resource information storage unit 18 (FIG. 7) and the information stored in the node number information storage unit 19 (FIG. 8), one route is selected from a plurality of routes. It is good.

  Processing in this case will be described with reference to FIG. The flowchart shown in FIG. 9 is obtained by replacing Step 3 and Step 4 in the flowchart of FIG. 6 with Step 3-1 to Step 4-2, and the other parts are the same as FIG.

  If it is determined in step 3-1 of FIG. 9 that there are a plurality of routes, the path passing ring network determination unit 12 first determines the total number of nodes for each ring on the route as described in step 4-1. If the route is uniquely determined (No in step 3-2), the process proceeds to step 5. When there are a plurality of paths (Yes in Step 3-2), a path with a large amount of free resources is selected as Step 4-2, and the process proceeds to Step 5.

  Instead of selecting the passing ring route according to the free resources and the number of nodes as described above, the route desired to be selected, such as the client's request, may be selected and the process may proceed to step 5.

  In the following description, it is assumed that the second route 1-4-4-6 has been selected as the path passing ring network. That is, assume that the route shown in FIG. 10 is selected.

  Next, the path passing ring network determination unit 12 performs a node connection relationship change process for the information stored in the internode connection information storage unit 17 (step 5 in FIGS. 6 and 9). That is, the path passing ring network determination unit 12 determines the node connection relationship related to the ring other than the ring on the route selected as the passing ring network (the connection relationship of the nodes not existing on the ring constituting the passing ring network) as the node Delete from the information stored in the inter-connection information storage unit 17.

  FIG. 11 shows information stored in the inter-node connection information storage unit 17 after deleting the node connection relationship. In this example, since the route 1-4-5-6 is selected as the route of the passing ring network, the ring numbers 2 and 3 other than (1, 4, 5, 6) are included in the example shown in FIG. All of the rows in the adjacent list of node numbers are replaced with -1.

  However, at the connection point between the rings, only when one of the two ring numbers is the ring number to be deleted, replace all of the rows with -1 and only one of the ring numbers. Is the deletion target ring number, only the node number including the deletion target ring number is replaced with -1.

  For example, since node number 2335 includes both ring number 2 and ring number 3 to be deleted, all node numbers in the row of this number are replaced with -1. On the other hand, for 3461, only 3 is included as the ring number to be deleted. Therefore, in this row, only 2335 and 33 including 3 as the ring number are changed to -1.

  The physical topologies of the inter-ring connection and inter-node connection corresponding to the inter-ring connection information (FIG. 11) after the change process in step 5 are as shown in FIGS. 12 and 13, respectively. As shown in FIGS. 12 and 13, the ring including the start point and the ring including the end point are each connected to only one other ring, and the intermediate ring is sandwiched between only two rings. There is only one, and in the subsequent path route search, a route search for a node closed in the one ring route is performed. Therefore, in determining two paths (paths for connection between nodes) of the path, the two paths pass through the same ring, and the problem that the paths are dispersed is solved.

Thereafter, the path route determination unit 13 determines the first route and the second route of the path connecting the start point node and the end point node, and the wavelength design unit 14 determines the wavelength to be assigned to each route (step 6). In the first embodiment, the path route determination method and the wavelength design method are not limited to specific methods. For example, a method described in each embodiment described later can be used.
[Second Embodiment]
Next, a second embodiment of the present invention will be described along the flowchart shown in FIG. In the second embodiment, first, similarly to the first embodiment, the path-passing ring network determining unit 12 performs the process of determining the route of the passing-ring network and changing the node connection relationship (see FIG. 6, processing up to step 5 in FIG. Below, it demonstrates based on the specific example used in 1st Embodiment. That is, the information shown in FIG. 11 to FIG. 13 is stored in the internode connection information storage unit 17 before the process of step 21 described below.

  In step 21 in FIG. 14, the path route determination unit 13 first searches for a first route (route for connection between nodes) of the path.

  Here, the path route determination unit 13 determines the first route by selecting a route having a small number of passing nodes. For example, in ring 1, the one having a smaller number of passing nodes is selected on the route from the starting point 15 to the inter-ring connecting node 1341.

  That is, based on the information shown in FIG. 11, the path route determination unit 13 determines that there are two types of routes from the node 15 to the node 1341, 15-141341 route and 15-11-1225-1341. The route of 15-141341, which is identified and has the smaller number of passing nodes, is selected. Thus, the route search in step 21 determines the first route as 15-14-1344-14255-2451-5265-64-63.

  Next, in step 22 of FIG. 14, the path route determination unit 13 searches for a second route. Here, as shown in FIG. 15, the path route determination unit 13 corresponds to the information stored in the internode connection information storage unit 17, and the node number corresponding to each link of the first route determined in step 21. By entering -1 in the column, the connection relation of the first route is deleted. The path route determination unit 13 can uniquely obtain the second route based on the information shown in FIG. 15 after rewriting. That is, in this example, the second route is determined as 15-11-1225-1341-45-44-43-4255-54-53-5265-3461-62-63. The first route and the second route are illustrated as shown in FIG.

  Subsequently, in step 23 in FIG. 14, the wavelength design unit 14 assigns wavelengths to the first route and the second route, respectively. Wavelength assignment can be performed using existing technology by referring to the wavelength assignment information stored in the wavelength information storage unit 20. As an existing technique, for example, the First-Fit algorithm described in Non-Patent Document 2 can be applied.

As described above, in the present embodiment, the shortest path between the start node and the end node is determined as the first path, and the second path is overlapped in the reverse direction within each ring. It is determined as a route that should not be. That is, in this embodiment, two routes are selected in each ring in the clockwise direction and the counterclockwise direction.
[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to the flowchart shown in FIG. In the third embodiment, first, similarly to the first embodiment, the path-passing ring network determining unit 12 performs the process of determining the path of the passing ring network and changing the node connection relationship (FIG. 6, processing up to step 5 in FIG. Below, it demonstrates based on the specific example used in 1st Embodiment. That is, the information shown in FIGS. 11 to 13 is stored in the internode connection information storage unit 17 at the time before the process of step 31 described below.

  In step 31 of FIG. 17, the path route determination unit 13 first searches for the first route of the path. Here, the path route determination unit 13 selects one first route by performing a route search using an all route search algorithm. Examples of the all-route search algorithm include a width-first search algorithm and a depth-first search algorithm.

  Next, the path route determination unit 13 searches for a second route (step 32). Here, the path route determination unit 13 performs each link of the route selected in step 31 on the information stored in the internode connection information storage unit 17 in the same manner as in step 22 in the second embodiment. Delete the connection relationship of. As a result, the second route is uniquely determined.

  Subsequently, the path route determination unit 13 calculates the absolute value of the difference between the number of hops (also the number of links) of the first route determined in step 31 and the number of hops of the second route determined in step 32, The information indicating the first route and the second route is stored in a storage means such as a memory (step 33). Here, instead of using the difference in the number of hops, a difference in path length between paths may be used. In this case, the path accommodation design apparatus 1 includes a path length storage unit that stores the path length of each link, and the path route determination unit 13 calculates the path length by referring to the path length storage unit.

  In step 34, the path route determination unit 13 determines whether all routes have been searched. The determination here may be a determination as to whether or not extraction of all the paths has been completed by combining the first path and the second path. That is, if the first route is determined, the second route is uniquely determined. Therefore, in the selection of the first route, the route that has already been selected as the second route may not be selected.

  If it is determined in step 34 that the search of all routes has not been completed, the path route determination unit 13 restores the connection relationship deleted in step 32 in the internode connection information storage unit 17, and step 31. Return to, and search for another route. This operation is performed for all routes.

  After the search of all routes is completed, the path route determination unit 13 sets a route set (first route) that minimizes the absolute value of the difference between the number of hops of the first route and the number of hops of the second route. And the second route) are selected as the first route and the second route (step 35). As a result, the problem that one route is significantly longer than the other route can be solved, and the possibility that both routes can be transmitted without a regenerative repeater can be increased.

  Subsequently, wavelength design is performed in the same manner as in the second embodiment (step 36).

As described above, in the present embodiment, the first route is searched by full route search, the second route is determined as a route that does not overlap with the first route, and the first route obtained by the search is One or both of the difference in the number of hops between the first route and the second route and the difference between the first route and the second route distance in the combination group of the second route is the minimum. A combination of the first route and the second route is determined as two routes of the path. Also in this embodiment, two paths are selected in the clockwise direction and the counterclockwise direction in each ring.
[Fourth Embodiment]
Next, the 4th Embodiment of this invention is described along the flowchart shown in FIG. In the fourth embodiment, first, similarly to the first embodiment, the path-passing ring network determining unit 12 performs the process of determining the path of the passing ring network and changing the node connection relationship (see FIG. 6, processing up to step 5 in FIG. Information shown in FIGS. 11 to 13 is stored in the inter-node connection information storage unit 17 at a time point before the process described below.

  In step 41 of FIG. 18, the path route determination unit 13 acquires information of each connection node that connects the rings from the node information of the passing ring network stored in the internode connection information storage unit 17. Since the passing ring network determined in the first embodiment is 1-4-5-6, the inter-ring connecting nodes are 1341, 4255, and 5265 (see FIG. 16). Is obtained and stored in a storage means such as a memory.

  Subsequently, the path route determination unit 13 searches for the first route (step 42). In the processing in step 42, a variable K is defined as an identifier for the number of route searches, and a variable L is defined as an identifier for whether or not the search for the first route has been completed. First, the path route determination unit 13 initializes K and L to 0 (step 101).

  Subsequently, if K is an even number (including 0), the path route determination unit 13 starts from the current node of interest (initially the starting point node) to the ring to which the node of interest belongs (ring that has not been searched). The shortest route (shortest hop route or shortest distance route) to the connection point node is obtained (steps 102 and 103). If K is an odd number, the longest route (longest hop route or longest distance route) from the current target node to the ring connection point node of the ring to which the target node belongs is obtained (steps 102 and 104).

  Thereafter, the path route determination unit 13 determines whether or not there is an end point node in the ring next to the ring subjected to the route search (step 105). If there is no node, go to step 106. In Step 106, 1 is added to K, and in Steps 102 to 104, the path calculation to the next ring connection point node is performed with the previous ring connection point node as the target node.

  In step 107, if K is an even number, the longest path from the current target node to the end node is obtained (steps 107 and 108). If K is an odd number, the shortest path from the current target node to the end node is obtained. A route is obtained (steps 107 and 109).

  That is, in the process of step 42, a route search from the start point node to the connection point node is performed in order, and K → K + 1 is set every time a route search in the ring is performed, and K = 2n (n is an integer of 0 or more). In the case of, a shortest path search is performed, and when K = 2n + 1, a conditional branch is performed so that the longest path search is performed. In the route search to the end node, without adding 1 to K before that, the longest route search is performed when K = 2n, and the shortest route search is performed when K = 2n + 1.

  The above processing corresponds to switching between the shortest and longest route search every time the ring is crossed. As a result, it is possible to reduce the case where only one of the first and second paths becomes long and transmission is impossible.

  Specifically, in the example shown in FIG. 13, first, the shortest route search from 15 to 1341 is performed, and then the longest route search from 1341 to 4255 is performed. Similarly, the shortest route search from 4255 to 5265 is performed, and finally the longest route search from 5265 to the end node 63 is performed. As a result, the first route is determined.

  Next, the path route determination unit 13 performs a second route search process (step 43 in FIG. 18). Here, the path route determination unit 13 determines whether L is 0 or 1 (step 110). Since L = 0 at first, the process proceeds to step 111, and each of L and K is set to 1. Thereafter, the processing from step 102 with the initial value of K set to 1 is performed. Since K starts from 1, in the search for the second route, the order in which the shortest route search and the longest route search are alternately performed is different from that in the first route search. A route that does not overlap with the route can be selected. Here, the path route determination unit 13 can determine which of the first route and the second route is calculated by referring to the value of L.

  Subsequently, wavelength design is performed in the same manner as in the second embodiment (step 44).

As described above, in this embodiment, the shortest path between the starting point node of the path and the inter-ring connecting point node on the ring to which the starting point node belongs is selected, and thereafter each of the rings to the ring to which the end point node belongs is selected. In the ring, the longest route and the shortest route connecting the inter-ring connection point nodes are alternately selected in order to determine the first route from the start point node to the end point node, and in the first route and each ring A route that does not overlap in the reverse direction is determined as the second route. Also in this embodiment, two paths are selected in the clockwise direction and the counterclockwise direction in each ring.
[Fifth Embodiment]
Next, a fifth embodiment will be described. In this embodiment, the initial setting of K is set to 1 (K → 1) in step 101 in step 42 of FIG. 18 described in the fourth embodiment, and K = 0 is set in step 111 of step 43. The other processes are the same as those shown in FIG.

  That is, the fifth embodiment performs the first route search using the second route search procedure described in the fourth embodiment, and the first route described in the fourth embodiment. The second route search is performed using the search procedure. As a result, it is possible to obtain the same effect as in the fourth embodiment.

As described above, in this embodiment, the longest path between the starting point node of the path and the inter-ring connecting point node on the ring to which the starting point node belongs is selected, and thereafter each of the rings to the ring to which the end point node belongs is selected. In the ring, the shortest path and the longest path connecting the inter-ring connection point nodes are alternately selected in order, thereby determining the first path from the start point node to the end point node. A route that does not overlap in the reverse direction is determined as the second route. Also in this embodiment, two paths are selected in the clockwise direction and the counterclockwise direction in each ring.
[Sixth Embodiment]
Next, a sixth embodiment of the present invention will be described with reference to the flowchart shown in FIG. Also in the sixth embodiment, first, similarly to the first embodiment, the path-passing ring network determining unit 12 performs processing for determining the passing ring network and changing the node connection relationship (FIG. 6, FIG. 9 to step 5). The subsequent processing from step 61 to 65 is the same as the processing from step 31 to step 35 in FIG. 17 described in the third embodiment.

  In the present embodiment, as a premise for the subsequent processing, the path transmission distance and the number of hops that can be transmitted (the maximum number of hops that can be used for signal transmission) are calculated in advance, and the values are stored in storage means such as a memory. It shall be. Further, the transmission distance of each link is also stored in the storage means. Note that the calculation of the transmittable distance and the transmittable hop count can be performed using an existing technique, and for example, can be calculated using the technique described in Non-Patent Document 3 or Non-Patent Document 4.

  After the route selection of the minimum hop count difference (or route count) in step 65 is completed, the path route determination unit 13 determines whether or not the hop count of the selected first route is equal to or less than the maximum hop count. (Step 66). That is, it is determined whether or not the first route is within the maximum hop count constraint.

  If it is determined in step 66 that the constraint is satisfied, the process proceeds to step 67; otherwise, the process proceeds to step 68.

  In step 67, the path route determination unit 13 determines whether or not the transmission distance of the first route is equal to or less than the preliminarily calculated transmission distance, that is, within the transmission distance range. If it is determined in step 67 that it is within the range of the transmittable distance, the process proceeds to step 70; otherwise, the process proceeds to step 68.

  In step 68, the path route determination unit 13 searches for the shortest route of the first route using the processing procedure described with reference to FIG. 14 in the second embodiment (step 21 in FIG. 14). In step 69, the path route determination unit 13 determines the second route in the same manner as in the second embodiment (step 22 in FIG. 14). That is, a route that does not overlap with the first route in the reverse direction in each ring is determined as the second route.

Thereafter, in step 70, wavelength design is executed in the same manner as in step 23 of the second embodiment.
[Seventh Embodiment]
Next, a seventh embodiment will be described with reference to FIG. In the seventh embodiment, first, similarly to the fourth embodiment described with reference to FIG. 18, the first route and the second route are determined, and then the sixth embodiment. This is a mode in which route determination is performed in consideration of transmission constraints in the same manner as in Step 66 to Step 70 in FIG.

In the processing flow of the seventh embodiment shown in FIG. 20, in steps 71 to 73, the same processing as in steps 41 to 43 of FIG. 18 in the fourth embodiment is performed, and in steps 74 to 78, The same processing as Step 66 to Step 70 in FIG. 19 of the sixth embodiment is performed.
[Eighth Embodiment]
Next, an eighth embodiment will be described.

  In the present embodiment, a path accommodation design method when eight service classes are considered is shown. The service class is determined by one or both of transmission quality and reliability, and is determined by, for example, a client's request. A processing method for determining a path and setting a path is determined according to the service class. In general, the higher the service class, the higher the transmission quality and reliability.

  In order to realize such processing, for example, a program for executing processing corresponding to each service class is stored in the storage unit of the path accommodation design apparatus 1 in association with the service class, and a certain service class is stored. Is input to the path accommodation design apparatus 1, the path accommodation design apparatus 1 may execute a program corresponding to the input service class. Further, the path accommodation design apparatus 1 includes processing means corresponding to each service class, receives the input of the service class, and performs processing corresponding to the service class by the processing means corresponding to the service class. May be.

  In the first service class in the present embodiment, the first route is designed with the shortest route, and the second route is designed so as not to overlap therewith. For this service class, the algorithm in the second embodiment can be used. In this service class, signal transmission may be performed through two paths. That is, a path may be accommodated in two routes.

  Any one of the algorithms described in the third to sixth embodiments is applied to the second service class.

  In the third service class, the first route is designed with the shortest route, the second route is designed so as not to overlap the first route, the route is secured, and at the time of failure of the first route, A method of accommodating a path in a second route (enabling signal transmission) is applied. For the third service class, the algorithm in the second embodiment can be used in the path accommodation design. However, accommodation of the path to the second route is only performed when the failure of the first route, and information on the path and wavelength of the client of the service class (used for accommodation of the path to the second route) Information etc.) is stored in the path accommodation design apparatus 1 or other management apparatus.

  In accommodating the path to the second route, it is necessary to set each node device on the second route so that the path signal can be transmitted. For example, the path control unit 15 of the path accommodation design apparatus 1 performs this. Alternatively, the management device described above may perform this. For the setting here, the information on the path and the wavelength is used. The management device is a device that selects and sets a wavelength and a path, for example, NMS (Network Management System), NRM (Network Resource Manager), PCE (Path computation Element), EMS (Element Management System), etc. . Further, the function of the path accommodation design device 1 may be provided in the management device.

  In the fourth service class, the first route is designed by applying the path accommodation design algorithm in the third to sixth embodiments, and the second route is designed not to overlap the first route. A path is secured, and the path is accommodated in the second path when the first path fails. However, the path accommodation to the second route is made only when the failure of the first route, and the route and wavelength of the client of this service class are stored in the management device.

  In the fifth service class, by using the path accommodation design algorithm in the second embodiment, the first route is designed with the shortest route, and the second route is designed so as not to overlap the first route. The secured second route is also used as the second route of this service class and the next sixth service class, and the second route is used when the first route fails. The path is accommodated in the route. The path accommodation to the second route is performed only when the first route fails, and the route and wavelength of the client of this service class are stored in the management device.

  In the sixth service class, the path accommodation design algorithm in the third to sixth embodiments is applied to design the first route, and the second route is designed not to overlap the first route. The route is secured, and the secured second route is also used as the second route of the present service class and the previous fifth service class, and the second route at the time of failure of the first route. To accommodate the pass. The path accommodation to the second route is performed only when the first route fails, and the route and wavelength of the client of this service class are stored in the management device.

  In the seventh service class, the first route is designed with the shortest route, the second route is designed when the first route fails, and the path is accommodated in the second route. Here, a path accommodation design algorithm in which the search for the second route in the second embodiment is omitted is used.

  The eighth service class is a method of designing the first route with the shortest route and not designing the second route. Here, the search for the second route in the second embodiment is omitted. Used path accommodation design algorithm.

That is, in the present embodiment, when the first service class is input to the path accommodation design apparatus 1, the path accommodation design apparatus 1 determines the first route on the passing ring network, and A process of determining a second route as a route that does not overlap with one route in the reverse direction in each ring, and switching the path to the second route when a path in which signal transmission is performed on the first route fails When the second service class is input to the path accommodation design apparatus 1, the path accommodation design apparatus 1 determines the first route on the passing ring network, and the first route and each ring The second route is determined as a route that does not overlap in the reverse direction, and when a path in which signal transmission is performed on the first route fails, the second route is switched to the second route. 2nd in 2 service classes Path is a path that is shared as a second path of different path of the second service class.
[Ninth Embodiment]
Next, a ninth embodiment of the present invention will be described. In the present embodiment, as shown in FIG. 21, a ring suitable for a network in which a ring having a start point node and a ring having an end point node are connected to the same ring via one connection point node, respectively. It is. Such a network corresponds to, for example, the Hierarchical self-healing ring network described with reference to FIG.

  In the network form shown in FIG. 21, there is only one passing ring network that connects the ring A having the start point node and the ring C having the end point node, and is described in the first embodiment. There is no need to perform a process of determining the passing ring network.

  Therefore, in the present embodiment, in the third embodiment described with reference to FIG. 17, the first route and the second route are determined by performing processing excluding the passing ring network determination processing. And wavelength design. That is, in the present embodiment, the processing of Step 31 to Step 36 shown in FIG. 17 is performed. By performing the processing of Step 31 to Step 36, the path length difference between the first path and the second path can be reduced in the network shown in FIG.

  Further, the network configuration to which this embodiment can be applied is not limited to that shown in FIG. This embodiment can also be applied to the network configuration shown in FIG. In the network configuration of FIG. 22, the path connecting the start node to the end node always passes through the rings 6, 7, and 9. Accordingly, since it is not necessary to determine the passing ring network for the ring networks 6, 7, and 9, the present embodiment can be applied as in the case described with reference to FIG. However, in the example shown in FIG. 22, in general, the path between the start point node and the connection point node of the ring 6 and the path between the end point node and the connection point node of the ring 9 are, for example, other It is necessary to obtain by the method described in the embodiment.

As described above, in the present embodiment, the first route is searched by the full route search, the step of determining the second route as a route that does not overlap the first route, and the first obtained by the search. One or both of the difference in the number of hops between the first route and the second route and the difference in the distance between the first route and the second route in the combination group of the route and the second route Determining a combination of a first route and a second route that minimizes as two routes of a path.
[Tenth embodiment]
The tenth embodiment is a form suitable for the network configuration shown in FIGS. 21 and 22 as in the ninth embodiment.

  In the present embodiment, in the fourth embodiment described with reference to FIG. 18, the determination of the first route and the second route is performed by performing processing excluding the determination processing of the passing ring network, and Perform wavelength design. That is, in the present embodiment, the processing of Step 41 to Step 44 shown in FIG. 18 is performed. By performing the processing from step 41 to step 44, the path length difference between the first path and the second path can be reduced.

That is, in this embodiment, the shortest path between the starting point node of the path and the inter-ring connection point node on the ring to which the starting point node belongs is selected, and thereafter, in each ring to the ring to which the end point node belongs, Determining the first route from the start point node to the end point node by alternately selecting the longest route and the shortest route connecting the inter-ring connection point nodes, and in the first route and each ring Determining a route that does not overlap in the reverse direction as the second route.
[Eleventh embodiment]
Similarly to the ninth embodiment, the eleventh embodiment is also a form suitable for the network configuration shown in FIGS.

  In the present embodiment, in the fifth embodiment described with reference to FIG. 18, the determination of the first route and the second route is performed by performing processing excluding the determination processing of the passing ring network, and Perform wavelength design. That is, in the present embodiment, the processing of Step 41 to Step 44 shown in FIG. 18 is performed. However, as described in the fifth embodiment, the value of K is different from that in the tenth embodiment. Also in this embodiment, the path length difference between the first path and the second path can be reduced.

That is, according to the present embodiment, the longest path between the starting point node of the path and the inter-ring connection point node on the ring to which the starting point node belongs is selected, and thereafter each ring to the ring to which the end point node belongs is selected. Determining the first route from the start node to the end node by alternately selecting the shortest route and the longest route connecting the inter-ring connection point nodes, and the first route and each ring A path accommodation design method comprising: determining a path that does not overlap in the opposite direction as the second path.
[Twelfth embodiment]
Similarly to the ninth embodiment, the twelfth embodiment is also a form suitable for the network configuration shown in FIGS.

  In the present embodiment, in the sixth and seventh embodiments described with reference to FIG. 19 and FIG. 20, the first route and the second route are obtained by performing processing excluding the pass ring network determination processing. The path is determined and the wavelength is designed. That is, in the present embodiment, the processing of Step 61 to Step 70 shown in FIG. 19 or Steps 71 to 78 shown in FIG. 20 is performed. By performing these processes, the route length difference between the first route and the second route can be reduced, and a route satisfying the restrictions on the number of hops and the transmission distance can be determined.

  That is, in the present embodiment, it is determined whether or not the transmission distance or the number of hops of the first route exceeds the pre-calculated transmission distance or the pre-calculated transmission hop number. A path accommodation design method comprising: a step of defining a first route as a shortest route between a start node and an end node; and determining a route that does not overlap in the opposite direction in each ring as a second route. Is provided.

  The present invention is not limited to the above-described embodiments, and various modifications and applications are possible within the scope of the claims.

DESCRIPTION OF SYMBOLS 1 Path accommodation design apparatus 11 Input / output part 12 Path passage ring network determination part 13 Path route determination part 14 Wavelength design part 15 Path control part 16 Inter-ring connection information storage part 17 Inter-node connection information storage part 18 Resource information storage part 19 Node Number information storage unit 20 Wavelength information storage unit

Claims (9)

A path accommodation design method executed by a path accommodation design apparatus having a function of determining a path of a path set on a multi-ring network including a plurality of rings in which a plurality of node devices are connected in a ring shape,
A passing ring network determining step for receiving information indicating a start point node and an information indicating an end point node of a path for which a route is to be determined, and determining a passing ring network composed of rings through which the path passes;
A path route determining step for searching for a route of the path within the range of the passing ring network determined by the passing ring network determining step ,
The path of the path is two paths, a first path and a second path,
In the path route determination step, the path accommodation design device includes:
Select the shortest path between the starting point node of the path and the inter-ring connecting point node on the ring to which the starting point node belongs, and thereafter connect the inter-ring connecting point node in each ring to the ring to which the end point node belongs. The first route from the start node to the end node is determined by alternately selecting the longest route and the shortest route in order,
A path accommodation design method , wherein a path that does not overlap in the opposite direction in each ring with the first path is determined as the second path . A path accommodation design method executed by a path accommodation design apparatus having a function of determining a path of a path set on a multi-ring network including a plurality of rings in which a plurality of node devices are connected in a ring shape,
A passing ring network determining step for receiving information indicating a start point node and an information indicating an end point node of a path for which a route is to be determined, and determining a passing ring network composed of rings through which the path passes;
A path route determining step for searching for a route of the path within the range of the passing ring network determined by the passing ring network determining step ,
The path of the path is two paths, a first path and a second path,
In the path route determination step, the path accommodation design device includes:
Select the longest path between the starting point node of the path and the inter-ring connecting point node on the ring to which the starting point node belongs, and thereafter connect the inter-ring connecting point node in each ring to the ring to which the end point node belongs. By selecting the shortest path and the longest path alternately in order, the first path from the start node to the end node is determined,
A path accommodation design method , wherein a path that does not overlap in the opposite direction in each ring with the first path is determined as the second path . The path accommodation design apparatus includes an inter-ring connection information storage unit that stores connection relation information between rings,
The information indicating the start point node includes identification information of a ring to which the start point node belongs, and the information indicating the end point node includes identification information of a ring to which the end point node belongs,
In the transit ring network determination step, the path accommodation design device includes:
Obtaining the identification information of the ring to which the start point node belongs from the information indicating the start point node, obtaining the identification information of the ring to which the end point node belongs from the information indicating the end point node;
The passing ring network is determined by searching for the shortest path between the rings identified by the identification information using the connection relation information between the rings stored in the inter-ring connection information storage means. The path accommodation design method according to claim 1 or 2 . When the identification information of the ring to which the start node belongs or the identification information of the ring to which the end node belongs is information indicating a plurality of rings, the path accommodation design apparatus is configured to 4. The path accommodation design method according to claim 3 , wherein a shortest path search is performed between each of the rings and the other ring. In the passing ring network determination step, when a plurality of routes are obtained as a result of the shortest route search, the path accommodation design device
For each of the plurality of routes, calculate the total free resource amount of each ring on the route, or the total number of nodes of each ring on the route,
Total maximum path of free resource amount, or by the total number of nodes selects the smallest path from the plurality of paths, claim 3, characterized by determining the passage ring network of the route or 4-pass accommodation design method according to. The path accommodation design apparatus includes an inter-node connection information storage unit that stores connection relation information between nodes, and the path accommodation design apparatus includes:
In the transit ring network determination step, from the connection relation information between nodes stored in the inter-node connection information storage means, delete the connection relation information of nodes that do not exist on the ring constituting the transit ring network,
In the path routing decision step, by using the information stored in the inter-node connection information storing means after the deletion, any one of claims 1 to 5, characterized in that to search for a route of the path The path accommodation design method described in 1. In the path route determination step, the path accommodation design device includes:
It is determined whether or not the transmission distance or the number of hops of the first route exceeds the pre-calculated transmission possible distance or the pre-calculated transmission hop number, and if so, the first route is set to the start point. The shortest path between the node and the destination node,
The path accommodation design method according to any one of claims 1 to 6 , wherein a path that does not overlap with the first path in the opposite direction in each ring is determined as the second path. The path accommodation design device comprises:
Processing means corresponding to each of the service classes defined by transmission quality and / or reliability,
The path accommodation design method according to any one of claims 1 to 7 , wherein processing corresponding to the service class is performed by a processing unit corresponding to the service class in response to an input of the service class. A path accommodation design method executed by a path accommodation design apparatus having a function of determining a path of a path set on a multi-ring network including a plurality of rings in which a plurality of node devices are connected in a ring shape,
A passing ring network determining step for receiving information indicating a start point node and an information indicating an end point node of a path for which a route is to be determined, and determining a passing ring network composed of rings through which the path passes;
A path route determining step for searching for a route of the path within the range of the passing ring network determined by the passing ring network determining step,
The path accommodation design apparatus includes processing means corresponding to each of the service classes determined by either or both of transmission quality and reliability, receives an input of the service class, and receives processing class corresponding to the service class. Is a device that performs processing corresponding to the service class,
When a first service class is input to the path accommodation design device, the path accommodation design device determines a first route on the passing ring network, and the first route and each ring Determining the second route as a route that does not overlap in the reverse direction, and performing a process of switching the path to the second route when a path in which signal transmission is performed on the first route,
When a second service class is input to the path accommodation design device, the path accommodation design device determines a first route on the passing ring network, and the first route and each ring Determining the second route as a route that does not overlap in the reverse direction, and performing a process of switching the path to the second route when a path in which signal transmission is performed on the first route,
The path accommodation design method, wherein the second route in the second service class is a route shared as a second route of another path of the second service class.

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