Transmission device, adaptation device and parameter adaptation procedure

Abstract

Transmission device (10), which is one of transmission devices (10) forming a network, wherein the transmission device (10) comprises: an information holding unit (11) to hold topology information of the network, and priority of the transmission facility (10) and priorities of other transmission facilities (10) forming the network, to be used in a path calculation; a shortest-path calculation unit (121) to calculate a shortest path from a first transmission facility (10) to a second transmission facility among the transmission facilities (10) forming the network, based on the topology information; and a priority adjustment unit (13) to adjust the priority of the transmission facility (10) on the basis of the shortest path calculated by the shortest path calculation unit (121) and the priority of the transmission facility (10) and the priorities of the other transmission facilities (10), wherein The priority adjustment unit (13) adjusts the priority of the transmission device (10) so that the number of overlaps with the priority of another transmission device (10) that is located with the transmission device (10) in a shortest path from a starting point to a destination and at the same distance from the starting point as the transmission device (10) is reduced.

Description

Area

[0001] The present invention relates to a transmission device which is one of transmission devices constituting a network, an adjustment device and a parameter adjustment method. background

[0002] Shortest-Path Bridging (SPB) is one of the means to improve network reliability (see Non-Patent Literature 1). According to SPB, each transmission device forming a network exchanges network topology information with other transmission devices, and all transmission devices perform path calculation individually. In this path calculation, multiple equal-distance shortest paths (ECMP: Equal-Cost Multipath) are calculated, which enables redundant paths and load balancing. To effectively perform load balancing, more paths must be obtained. Through path calculation by SPB, up to 16 shortest paths can be obtained between two transmission devices. However, the number of paths obtained by SPB depends on a parameter called the bridging priority of each of the transmission devices arranged in the shortest paths.

[0003] DE 11 2012 006 604 T5 describes methods and apparatus relating to network routing protocols to support energy savings in network elements.

[0004] DE 698 28 664 T2 describes a route selection method for selecting a route that satisfies a condition regarding a quality of service from a plurality of routes that connect a starting point with an end point. List of cited publicationsNon-patent literature

[0005] Non-Patent Literature 1: IEEE P802.1aq / D4.6, 2012 SummaryTechnical problem

[0006] To increase the number of paths calculated using the SPB, the bridge priorities of the transmission devices must be adjusted. However, in the current state of the art, the bridge priority adjustment is performed manually by each transmission device, resulting in insufficient network functionality and scalability.

[0007] The present invention has been realized in view of the above and an object is to provide a transmission device capable of automatically adjusting the bridge priority to be used in the path calculation Solution to the problem

[0008] To solve the above-mentioned problems and objectives, the present invention provides a transmission device that is one of transmission devices constituting a network. The transmission device includes: an information holding unit that holds topology information of the network, and the priority of the transmission device and the priorities of other transmission devices constituting the network, for use in path calculation; and a shortest path calculation unit that calculates a shortest path from a first transmission device to a second transmission device among the transmission devices constituting the network based on the topology information.The transmission device also includes a priority adjustment unit that adjusts the priority of the transmission device based on the shortest path calculated by the shortest path calculation unit and the priority of the transmission device and the priorities of the other transmission devices, wherein the priority adjustment unit adjusts the priority of the transmission device so that the number of overlaps with the priority of another transmission device that is arranged with the transmission device in a shortest path from a starting point to a destination and at an equal distance from the starting point as the transmission device is reduced. Advantageous effects of the invention

[0009] A transmission device according to the present invention enables automatic adjustment of the bridge priority to be used in the path calculation. Brief description of the drawings Fig. 1 is a diagram illustrating an example of a network formed by transmission devices according to a first embodiment. Fig. 2 is a diagram illustrating an exemplary functional configuration of a transmission device according to the first embodiment. Fig. 3 is a diagram illustrating an exemplary hardware configuration of the transmission device according to the first embodiment. Fig. 4 is a flowchart illustrating an example of the operation of a priority adjustment unit according to the first embodiment. Fig. 5 is a diagram showing an example of the network formed by the transmission devices according to the first embodiment. Fig. 6 is an exemplary functional configuration of an adaptation device according to a second embodiment. Fig. 7 is a diagram illustrating an exemplary hardware configuration of the adaptation device according to the second embodiment. Fig. 8 is a flowchart illustrating an example of the operation of a priority adjustment unit according to the second embodiment. Description of the embodiments

[0010] A transmission device, a matching device, and a parameter matching method according to certain embodiments of the present invention will be described in detail below with reference to the drawings. It should be noted that the present invention is not limited to the embodiments. First embodiment.

[0011] Fig. 1 is a diagram illustrating an example of a network formed by transmission devices according to a first embodiment of the present invention. Fig. The network illustrated in Figure 1 is formed by switching devices 10, which are transmission devices according to the first embodiment. Terminal devices 20 can be connected to each of the switching devices 10. Each of the switching devices 10 exchanges network topology information with the other switching devices 10 forming the network and retains the topology information collected by the other switching devices 10. Furthermore, each of the switching devices 10 determines a path to each of the other switching devices 10, that is, a communication path for communication with each of the other switching devices 10 through the SPB. The terminal devices 20 communicate with other terminal devices 20 via the network formed by the switching devices 10. In Fig. In Figure 1, solid lines represent links between the switching devices 10 and the terminal devices 20 and correspond to the communication paths. A communication path between two switching devices 10 is also referred to as a link. Note that in the following description, the switching devices 10 may be referred to as nodes.

[0012] Fig. 2 is a diagram illustrating an exemplary functional configuration of a switching device according to the first embodiment. As shown in Fig. 2, the switching device 10 comprises a link state database 11, a routing unit 12 and a priority adjustment unit 13. The routing unit 12 comprises a shortest path calculation unit 121 and a path selection unit 122. It should be noted that Fig. 2 illustrates the main components of the switching device 10, or more specifically, the functional blocks required for setting up communication paths for communication with the other switching devices 10, and omits the illustration of other functional blocks included in typical switching devices. Examples of other functional blocks included in typical switching devices include functional blocks for the switching device 10 to perform communication with other communication devices, which are the other switching devices 10 or the terminal devices 20, that is, functional blocks for the switching device 10 to transmit and receive signals to and from other communication devices.

[0013] The link state database 11 contains topology information of the network formed by the switching devices 10 (hereinafter referred to as topology information) and the bridge priority, which is the priority of each switching device 10. The link state database 11 is an information holding unit. The topology information includes information about links between the switching devices 10 and the link cost. Link cost is information about the quality of each link between switching devices 10. Link cost is, for example, a bandwidth of each link. The bridge priority is a parameter defined in Non-Patent Literature 1. As described above, the bridge priority is used for routing via the SPB. Thus, the bridge priority is the priority of each of the switching devices 10, which is used in path calculation.An initial value of the bridge priority is set externally in the link state database 11 by a network administrator or the like.

[0014] The routing unit 12 sets shortest paths for all combinations of the switching devices 10 forming the network based on the topology information and bridge priority contained in the link state database 11. The routing unit 12 uses the SPB in routing. The SPB is implemented through the operation of the shortest path calculation unit 121 and the path selection unit 122.

[0015] The shortest-path calculation unit 121 of the routing unit 12 calculates shortest paths from a first switching device, i.e., a first transmission device that is one of the switching devices 10 constituting the network, to a second switching device, i.e., a second transmission device that is one of the switching devices 10 other than the first switching device, based on the topology information held by the link state database 11. The shortest-path calculation unit 121 calculates shortest paths between all pairs of switching devices 10 constituting the network. To calculate the shortest paths from the first switching device to the second switching device, the shortest-path calculation unit 121 uses Dijkstra's algorithm described in a reference: "A Note on Two Problems Relating to Graphs (Numerical Mathematics, 1959, Vol. 1, pp. 269-271)."

[0016] In a case where there are a plurality of shortest paths from a switching device 10 that is a starting point to a switching device 10 that is an end point, the path selection unit 122 of the routing unit 12 selects one of the shortest paths through a tie-breaking algorithm. Specifically, in the case where there are a plurality of shortest paths connecting two switching devices 10 in a calculation result from the shortest path calculation unit 121, the path selection unit 122 selects one of the shortest paths and notifies the shortest path calculation unit 121 of the selection result. The tie-breaking algorithm selects one of the shortest paths from the switching device 10, that is, the starting point, to the switching device 10, that is, the end point, based on bridge identifications (IDs) of the switching devices 10 constituting the network.A bridge ID is identification information of a switching device 10, obtained by combining the bridge priority and the MAC (Media Access Control) address of the switching device 10. Since the bridge priority is 2 bytes long, a bridge ID is 8 bytes long. In the following description, a bridge ID may be referred to as a BID.

[0017] Details of the path selection operations performed by the shortest path calculation unit 121 and the path selection unit 122 of the routing unit 12, that is, path selection operations with the combination of the Dijkstra's algorithm and the tie-breaking algorithm, are described in Non-Patent Literature 1.

[0018] The priority adjustment unit 13 adjusts the bridge priority, maintained by the link state database 11, of the switching device 10 having the priority adjustment unit 13 based on path information. The path information used for adjusting the bridge priority is information about the shortest paths of all combinations of the switching devices 10 constituting the network.For example, in a case where the switching devices 10 forming the network are switching devices 101 to 105, the path information includes information about shortest paths between the switching device 101 and the switching device 102, shortest paths between the switching device 101 and the switching device 103, shortest paths between the switching device 101 and the switching device 104, shortest paths between the switching device 101 and the switching device 105, shortest paths between the switching device 102 and the switching device 103, shortest paths between the switching device 102 and the switching device 104, shortest paths between the switching device 102 and the switching device 105, shortest paths between the switching device 103 and the switching device 104, shortest paths between the switching device 103 and the switching device 105 and shortest paths between the switching device 104 and the switching device 105.It should be noted that according to the SPB, the upper four bits of the bridge priority can be changed out of 16 bits. Thus, the priority adjustment unit 13 performs the adjustment on the upper four bits of the bridge priority. Details of the bridge priority adjustment process performed by the priority adjustment unit 13 will be described later.

[0019] The hardware for implementing a switching device 10 is described below. Fig. Figure 3 is a diagram illustrating an exemplary hardware configuration of a switching device according to the first embodiment. The switching device 10 may be implemented by a processor 101, a memory 102, and data transmission hardware 104, as shown in Fig. 3. The processor 101, the memory 102, and the data transmission hardware 104 are connected via a bus 103.

[0020] The processor 101 is a central processing unit (CPU; also referred to as a central processor, processing unit, calculation unit, microprocessor, microcomputer, processor, or digital signal processor (DSP)), a system LSI (Large Scale Integration), or the like. The memory 102 is a non-volatile or volatile semiconductor memory such as a random access memory (RAM), a read-only memory (ROM), a flash memory, an erasable programmable read-only memory (EPROM), or an electrically erasable programmable read-only memory (EEPROM), a magnetic disk, a flexible disk, an optical disk, a compact disc, a mini disc, a digital versatile disk (DVD), or the like.

[0021] The link state database 11 of the switching device 10 is implemented by the memory 102. The routing unit 12 and the priority adjustment unit 13 of the switching device 10 are realized by software, firmware, or a combination of software and firmware. Software and firmware are described in the form of programs and stored in the memory 102. The routing unit 12 and the priority adjustment unit 13 are implemented by the processor 101 by reading programs for functioning as the routing unit 12 and the priority adjustment unit 13 from the memory 102 and executing the read programs. In particular, the switching device 10 includes the memory 102 for storing programs that, when the functions of the switching device 10 are executed by the processor 101, cause the execution of steps for performing the functions of the routing unit 12 and the priority adjustment unit 13.In other words, the programs cause a computer to execute the processes to be directed by the routing unit 12 and the priority adjustment unit 13.

[0022] The routing unit 12 and the priority adjustment unit 13 may be implemented by dedicated hardware. The dedicated hardware is a standalone circuit, a composite circuit, a programmed processor, a parallel-programmed processor, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or a combination thereof. One of the routing unit 12 and the priority adjustment unit 13 may be implemented by dedicated hardware, and the other may be implemented by the processor 101 and the memory 102.

[0023] The data transmission hardware 104 is used when the switching device 10 receives data from another switching device 10 or a terminal device 20, and when the switching device 10 transmits received data to another switching device 10 or a terminal device 20. The data transmission hardware 104 is also used to receive information to be stored in the link state database 11 from the outside.

[0024] Next, the operation of the priority adjustment unit 13 for adjusting the bridge priority stored in the link state database 11 will be described.

[0025] Fig. Fig. 4 is a flowchart illustrating an example of the operation of the priority adjustment unit 13 according to the first embodiment. In particular, Fig. 4 is a flowchart illustrating an example of an operation in a case where the priority adjustment unit 13 adjusts the bridge priority stored in the link state database 11 of the switching device 10 having the priority adjustment unit 13.

[0026] In the present embodiment, the operation will be described with reference to a case where the switching devices 10 connect a network having a Fig. 5 as an example configuration. In Fig. 5, circles (◯) represent nodes that are switching devices 10, and numbers in the circles are identifiers of the nodes. The numbers and dashes described above, where each circle represents a node, show the shortest paths from a root node, which is a node at a starting point, to another node. The left numerical end value of the shortest paths represents the identifier of the root node, and the right numerical end values ​​of the shortest paths represent the identifiers of the destination nodes, which are nodes at endpoints. The numerical values ​​that correspond to neither the left nor the right ends of the shortest paths represent identifiers of nodes located on the shortest paths. In the following description, a node with the identifier "N" (N = 1, 2, 3, ...) is referred to as a node N. In the Fig. In the example shown in Figure 5, node 0 is the root node. For example, there are two shortest paths from node 0 to node 4. Specifically, a path represented by "0-1-4" from node 0 to node 4 via node 1 and a path represented by "0-2-4" from node 0 to node 4 via node 2 are the shortest paths from node 0 to node 4.

[0027] When a preset condition is met, for example, when the topology information or the bridge priority contained in the link state database 11 is changed or when an instruction from a network administrator is received externally, the priority adjustment unit 13 executes the process according to the procedure described in Fig. 4 flowchart shown.

[0028] The priority adjustment unit 13 first acquires the path information from the shortest path calculation unit 121 (step S11). The path information received by the priority adjustment unit 13 from the shortest path calculation unit 121 in step S11 is information about all the shortest paths between all combinations of two nodes in the network. It is assumed that the shortest path calculation unit 121 completes the shortest path calculation, that is, the calculation of all the shortest paths between all combinations of two nodes in the network using Dijkstra's algorithm. Alternatively, the shortest path calculation unit 121 may calculate the shortest paths upon request of path information from the priority adjustment unit 13 to generate the path information and output the path information to the priority adjustment unit 13.

[0029] For example, in the case where the network formed by the switching devices 10 is the one in Fig. 5, the priority adjustment unit 13 acquires information about the shortest paths from each of the nodes 1 to 8 as a root node to each of the other nodes from the shortest path calculation unit in step S121, in addition to the information about the shortest paths from node 0 as the root node to each of the nodes 1 to 8. Thus, the priority adjustment unit 13 acquires information about the shortest paths from the nodes nr to the nodes nd (nr≠nd, and nr, nd=0, 1, 2, ...., 8) from the shortest path calculation unit 121.

[0030] Subsequently, the priority adjustment unit 13 checks the path information acquired in step S11 and classifies the nodes on the shortest paths for each destination according to the distance from the root node (step S12). In the case of the Fig. In the network illustrated in Figure 5, the shortest paths from node 0 to node 4 are two paths, which are, for example, a path represented by "0-1-4" and a path represented by "0-2-4." Thus, the priority adjustment unit 13 stores node 1 and node 2 as nodes that satisfy a condition of root node = node 0, destination node = node 4, and distance from the root node = 1. Similarly, in a case of root node = node 0 and destination node = node 7, the priority adjustment unit 13 stores node 1, node 2, and node 3 as nodes that satisfy a condition of distance from the root node = 1, and stores node 4 and node 5 as nodes that satisfy a condition of distance from the root node = 2. The cases of root node=node 0 and target node=node n (n=5, 6, 8) are similar to those described above.The priority adjustment unit 13 performs processing similar to that in the case of root node = node 0 on all combinations of two nodes in the network. In the case of the in . Fig. 5, the priority adjustment unit 13 performs processing similar to the processing in the case of root node = node 0 when each of nodes 1 to 8 is a root node. Thus, the priority adjustment unit 13 classifies the nodes forming the shortest paths into groups of nodes equidistant from node nr for each of the pairs of node nr and node nd (nr≠nd, and nr, nd=0, 1, 2, ....., 8).

[0031] Next, the priority adjustment unit 13 selects a node with a non-adjusted bridge priority as a node to be adjusted from among the nodes classified in step S12 above (step S13). The manner of selecting the node may be, but is not limited to, selection in ascending order of the bridge IDs of the nodes, random selection, or the like.

[0032] Next, the priority adjustment unit 13 selects a candidate for the bridge priority of the node to be adjusted selected in step S13 above from 0x0 to 0xF (step S14). Note that the candidate for the bridge priority to be selected is actually a candidate for the upper four adjustable bits of the bridge priority, expressed in 16 bits. In the following description, to avoid complicating the description, the "candidate for the bridge priority" is used as a term that means the "candidate for the upper four bits of the bridge priority." The manner in which the candidate for the bridge priority is selected may be, but is not limited to, selection in ascending order from 0x0 to 0xF, random selection from 0x0 to 0xF, or the like.In subsequent steps S15 and S16, the priority adjustment unit 13 performs processing to replace the bridge priority of the node to be adjusted selected in step S13 with a value specified by the candidate for the bridge priority selected in step S14. The processing in step S14 can be referred to as a process for provisionally determining the bridge priority. The processing in steps S15 and S16 can be referred to as a process for evaluating the provisionally determined bridge priority.

[0033] Next, the priority adjustment unit 13 performs the following processing for each of the groups of nodes, each of which is a group of nodes that form the shortest paths from a root node (node ​​nr) to a destination node (node ​​nd) and are located at the same distance from the root node, obtained by the classification in step S12 above. The priority adjustment unit 13 first performs an exclusive OR (XOR) operation of bridge IDs on all node pairs belonging to one of the node groups obtained in step S12 above. Furthermore, the priority adjustment unit 13 checks the operation result of each of the pairs in units of four upper bits.Specifically, the priority adjustment unit 13 checks each of the operation results in units of four upper bits. If four bits with one bit set are found, that is, if four bits indicating a value other than 0 are found, it extracts the found four bits, then changes the other bits except the most significant bit '1' of the extracted four bits to '0', and performs an OR operation on the changed extraction results (step S15). The priority adjustment unit 13 can acquire the bridge ID of each node via the shortest path calculation unit 121 or directly from the link state database 11.

[0034] A concrete example of the processing in step S15 is described. In the case of the Fig. 5, the priority adjustment unit 13 stores {node 1, node 2, node 3} as a group of nodes corresponding to the root node=node 0, the target node=node 7, and the distance from the root node=1 in step S12 above. In this case, in step S15, the priority adjustment unit 13 first performs an exclusive-OR (XOR) operation ((BID of node 1)^(BID of node 2)) of the bridge ID (BID) of node 1 and the BID of node 2 as an operation #1, performs an exclusive-OR (XOR) operation ((BID of node 1)^(BID of node 3)) of the BID of node 1 and the BID of node 3 as an operation #2, and performs an exclusive-OR (XOR) operation ((BID of node 2)^(BID of node 3)) of the BID of node 2 and the BID of node 3 as an operation #3.Subsequently, assuming that the result of operation #1 is 0x30000000000000000, the result of operation #2 is 0x0000F00000000000, and the result of operation #3 is 0x000000000000007, the priority adjustment unit 13 extracts 0x3, that is, the four bits of '0011' from the result of operation #1, extracts 0xF, that is, the four bits of '1111' from the result of operation #2, and extracts 0x7, that is, the four bits of '0111' from the result of operation #3. The priority adjustment unit 13 then changes "1" to "0" of the four bits extracted from each of the operation results, except for the most significant bit "1," and calculates the OR of all four bits resulting from the changes. Specifically, an OR operation of "0010," "1000," and "0100" is performed. In this case, an operation result of (0010 | 1000 | 0100) = 1110 is obtained.The priority adjustment unit 13 performs the above processing on all groups of nodes obtained by the classification in step S12 above.

[0035] Next, the priority adjustment unit 13 compares the results of the operations in step S15 above between those with the same destination and different distances from the same root node, and stores the number of set intersecting bits (step S16). For example, in a case where the distance from a root node to a destination node is 4, the result of the operation in the processing performed on the group of nodes at a distance of 1 from the root node, the result of the operation in the processing performed on the group of nodes at a distance of 2 from the root node, and the result of the operation in the processing performed on the group of nodes at a distance of 3 from the root node in step S15 above are compared, and the number of set intersecting bits is stored.

[0036] A concrete example of the processing in step S16 is described. Consider a case where node 0 is a root node (root node = node 0) and node 7 is a target node (target node = node 7) in the Fig. 5. In this case, the group of nodes satisfying the distance from the root node = 1 is {node 1, node 2, node 3}, and the group of nodes satisfying the distance from the root node = 2 is {node 4, node 5}. In a case where the result of the operation (operation result A) on {node 1, node 2, node 3} in step S15 above is '1110' and the result of the operation (operation result B) on {node 4, node 5} in step S15 above is '0100', the second bits of the most significant bits in both operation results A and B are set (bit = 1), and the bits other than the second bits of the most significant bits in one or both of the operation results A and B are 0. Thus, the number of overlapping bits = 1 is obtained. The priority adjustment unit 13 performs the above processing for each of the pairs of the node nr and the node nd (nr≠nd, and nr, nd=0, 1, 2, ...., 8).The priority adjustment unit 13 then adds the numbers of overlapping bits calculated for the respective pairs of node nr and node nd, and stores the result of adding the numbers of overlapping bits as the result of evaluation of the candidate for the bridge priority selected in step S14 above.

[0037] Next, the priority adjustment unit 13 checks whether or not all of 0x0 to 0xF have been selected as candidates for the bridge priority of the node selected in step S13 above in step S14 (step S17). Specifically, the priority adjustment unit 13 checks whether or not the above steps S15 and S16 have been performed, with the bridge priority of the node selected in step S13 being set to all possible values. If all of 0x0 to 0xF have been selected as candidates for the bridge priority of the node selected in step S13 above in step S14 and the determination in step S17 is "Yes", a total of 16 numbers of intersecting bits, which are the respective operation results in S16 for 0x0 to 0xF, are stored.In other words, if “Yes” is determined in step S17, the priority adjustment unit 13 stores the results of evaluation of the respective candidates for the bridge priority selected in step S13.

[0038] If any candidate not selected in step S14 above exists among 0x0 to 0xF (step S17: No), the operation of the priority adjustment unit 13 returns to step S14 above, and the priority adjustment unit 13 selects one of the unselected bridge priority candidates, that is, the bridge priority candidates for which the calculation of an evaluation result was not performed in steps S15 and S16 above. The priority adjustment unit 13 then executes the above steps S15 and S16 on the selected bridge priority candidate.When all of 0x0 to 0xF have been selected in step S14, that is, the calculation of an evaluation result in steps S15 and S16 has been performed on all the candidates for the bridge priority (step S17: Yes), the priority adjustment unit 13 performs a check of the group of nodes to which the node to be adjusted, which is the node selected in step S13 above, belongs, among the groups of nodes obtained by the classification in step S12 above, to check whether any candidate that does not overlap with the bridge priority of nodes having the same destination and at a distance from the same root node equal to that of the node to be adjusted exists or not in the candidates 0x0 to 0xF of the bridge priority (step S18).

[0039] A concrete example of the processing in step S18 is described. A case is considered in which node 0 is a root node (the root node = node 0) and node 7 is a target node (the target node = node 7) in the Fig. 5. In this case, the set of nodes satisfying the distance from the root node = 2 is {node 4, node 5}. Assume that node 5 is the node selected in step S13 above, and the bridge priority of node 5 is to be adjusted. Thus, node 5 is the node to be adjusted. In this case, the bridge priority with the same value as the bridge priority of node 4, which is not the node to be adjusted, is a candidate for the bridge priority that overlaps between nodes with the same destination and at the same distance from the same root node. The bridge priority with a different value than the bridge priority of node 4 is not a candidate for the bridge priority that overlaps between nodes with the same destination and at the same distance from the same root node.Similar check processes are performed on the other node groups to which node 5, which is the node to be adjusted, belongs. If, in all the node groups to which node 5 belongs, there are one or more bridge priorities that do not correspond to the "candidate for the bridge priority that overlaps between nodes with the same destination and at the same distance from the same root node," the determination result in step S18 above is "Yes." In other words, in step S18 above, the priority adjustment unit 13 checks the bridge priorities of the nodes other than the node to be adjusted in the node groups to which the node to be adjusted belongs, and determines as "Yes" whether there is a bridge priority that is not set for any of the nodes other than the node to be adjusted.

[0040] If the determination result in step S18 is "Yes," the priority adjustment unit 13 determines, as the adjusted bridge priority of the node to be adjusted (the node selected in step S13 above), the candidate with the smallest number of overlapping bits stored in step S16 above among the bridge priority candidates that overlap between nodes with the same destination and at the same distance from the same root node (step S19). For example, in a case where 0x2 to 0x7 exist as bridge priorities that are not set in any of the nodes except the node to be adjusted in the respective node groups to which the node to be adjusted belongs in step S18 above, the candidate with the smallest number of overlapping bits calculated in step S16 above among 0x2 and 0x7 is determined as the adjusted bridge priority of the node to be adjusted.On the other hand, when the determination result in step S18 above is "No", the priority adjustment unit 13 determines, as the adjusted bridge priority of the node to be adjusted, a value corresponding to the candidate with the smallest number of overlapping bits calculated in step S16 above before all candidates (0x0 to 0xF) for the bridge priority (step S20).

[0041] Next, the priority adjustment unit 13 checks whether the adjusted bridge priority of the node having the priority adjustment unit 13 has been determined (step S21). If the adjusted bridge priority of the node has not been determined (step S21: No), the operation of the priority adjustment unit 13 returns to step S13. If the adjusted bridge priority of the node has been determined (step S21: Yes), the priority adjustment unit 13 updates the bridge priority of the node having the priority adjustment unit 13 in the link state database 11 with the bridge priority determined in step S19 or S20 above (step S22).

[0042] After updating the bridge priority of the switching device 10 in step S22, the switching device 10 notifies the other switching devices 10 of the updated bridge priority. Furthermore, in a case where the switching device 10 has received notification of the updated bridge priority from another switching device 10, the switching device 10 overwrites the link state database 11 with the bridge priority for which a notification is received to update the information, and executes the process according to the Fig. 4 using the updated bridge priority to adjust the bridge priority of the switching device 10.

[0043] As described above, in the switching device according to the present embodiment, the priority adjustment unit selects one of the possible bridge priorities to be preliminarily determined as the adjusted bridge priority of the switching device, and performs the process of evaluating the preliminarily determined bridge priority against all possible bridge priorities. Specifically, the priority adjustment unit evaluates the preliminarily determined bridge priority based on the shortest path information from a first switching device to a second switching device included in the network and the bridge IDs of the switching device including the priority adjustment unit and the other switching devices.The priority adjustment unit also determines the adjusted bridge priority of the switching device in which the priority adjustment unit is arranged based on the evaluation results of the respective possible bridge priorities. When calculating an evaluation result, the priority adjustment unit first performs an XOR operation of bridge IDs on all pairs of switching devices belonging to the same group for each of the groups of switching devices with the same destination and at the same distance from the same starting point. Further, it extracts four bits that satisfy a predetermined condition from the XOR operation results, changes bits '1' except for the most significant bit '1' to '0' among the four bits extracted from each of the operation results, and performs an OR operation on the changed four bits to generate a first operation result.The priority adjustment unit then compares the first operation results of the groups of switching devices with the same destination and at different distances from the same starting point to generate a second operation result as a result of evaluating the preliminarily determined bridge priority. Four bits that satisfy the preset condition are the upper four bits of an XOR operation result, including the most significant bit, which is "1."

[0044] According to the switching device of the present embodiment, the bridge priority to be used in path calculation by the SPB is automatically adjusted. This reduces the number of items that must be manually set by a network administrator or the like in the switching devices, improving network operability and scalability. Second embodiment.

[0045] In the first embodiment, each of the switching devices constituting a network determines an adjusted value of the bridge priority of the switching device itself. In contrast, in the present embodiment, a device collectively determines adjusted values ​​of the bridge priorities of all the switching devices constituting a network. The determination of the adjusted values ​​of the bridge priorities may be determined by a representative switching device or by a device other than the switching devices. In the present embodiment, a case will be described where a device other than the switching device determines adjusted values ​​of the bridge priorities of the switching device.

[0046] Fig. 6 is an exemplary functional configuration of a matching device according to the second embodiment. A matching device 30 includes an input unit 31, a routing unit 32, a priority matching unit 33, and an output unit 34. The routing unit 32 includes a shortest path calculation unit 321 and a path selection unit 322. The routing unit 32, the shortest path calculation unit 321, and the path selection unit 322 of the matching device 30 are the same functional blocks as those of the routing unit 12, the shortest path calculation unit 121, and the path selection unit 122 included in the switching device 10 of the first embodiment.

[0047] The priority adjustment unit 33 of the adjustment device 30 determines an adjusted value of the bridge priority of each of the switching devices constituting the network by methods similar to those performed by the priority adjustment unit 13 according to the first embodiment. While the priority adjustment unit 13 according to the first embodiment terminates the process of determining an adjusted value when the adjusted value of the bridge priority of the switching device in which the priority adjustment unit 13 is included is determined, the priority adjustment unit 33 according to the present embodiment continues processing until the adjusted values ​​of the bridge priorities of all the switching devices are determined.

[0048] The input unit 31 is an information acquisition unit for acquiring topology information of a network from the outside and inputting the acquired topology information to the shortest path calculation unit 321.

[0049] The output unit 34 outputs the adjusted values ​​of the bridge priorities of the respective switching devices determined by the priority adjustment unit 33 to the outside. The output unit 34 is implemented by a display device or a transmission device. In a case where the output unit 34 is implemented by a display device, the output unit 34 functions as a display unit to inform a network administrator or the like of the adjusted values ​​of the bridge priorities. In a case where the output unit 34 is implemented by a transmission device, the output unit 34 functions as a transmission unit for transmitting the adjusted values ​​of the bridge priorities to the switching devices. The output unit 34 can be implemented by a display device and a transmission device and functions as the display unit and the transmission unit.

[0050] Fig. Fig. 7 is a diagram illustrating an exemplary hardware configuration of an adaptation device according to the second embodiment. The adaptation device 30 may be implemented by a processor 101, a memory 102, an input device 105, and an output device 106, which are shown in Fig. 7. The processor 101, the memory 102, the input device 105, and the output device 106 are connected via a bus 103. The processor 101 and the memory 102 are similar to the processor 101 and the memory 102 described in the first embodiment. The input device 105 may be, for example, but is not limited to, a keyboard, a touch pad, a microphone, or the like. The output device 106 may be, but is not limited to, a display (also referred to as a monitor or a screen), a speaker, a transmission device, or the like.

[0051] Fig. 8 is a flowchart showing an example of the operation of the priority adjustment unit 33. The Fig. The flowchart shown in Figure 8 differs from the one in Fig. 4 in that steps S21 and S22 are replaced by steps S31 and S32. Since the Fig. 8 are similar to the steps S11 to S20 described in the first embodiment, their description will not be repeated.

[0052] After performing step S19 or step S20, the priority adjustment unit 33 checks whether or not a node with a non-adjusted bridge priority exists, that is, whether adjusted values ​​of the bridge priorities of all the nodes to be adjusted that constitute the network have been determined (step S31). If a node with a non-adjusted bridge priority exists (step S31: Yes), the operation of the priority adjustment unit 33 returns to step S13. If no node with a non-adjusted bridge priority exists (step S31: No), the priority adjustment unit 33 sends all the adjusted bridge priorities to the output unit 34 (step S32). In a case where the output unit 34 is a display or the like, the output unit 34 displays the adjusted bridge priorities upon receiving the adjusted bridge priorities from the priority adjustment unit 33.

[0053] While the adjustment device collectively determines the adjusted values ​​of the bridge priorities of the respective switching devices, one of the switching devices forming the network may collectively determine the adjusted values ​​of the bridge priorities of the respective switching devices as described above. In the case where a switching device collectively determines the adjusted values ​​of the bridge priorities of the respective switching devices, the switching device that determines the adjusted values ​​notifies the other switching devices of the determined adjusted values ​​of the bridge priorities of all switching devices after determining the adjusted values.

[0054] As described above, in the present embodiment, one device collectively performs the determination of the adjusted values ​​of the bridge priorities of the respective switching devices constituting a network. As a result, all the switching devices do not need to perform similar processing, which reduces the processing loads on the switching devices as a whole. Moreover, the adjusted values ​​of the bridge priorities of the respective switching devices can be obtained at high speed. Furthermore, in a case where an adjusting device other than the switching devices determines the adjusted values ​​of the bridge priorities of the respective switching devices, optimal values ​​of the bridge priorities of the respective switching devices can be obtained before constructing a network.

[0055] The configurations shown in the above embodiments are examples of the present invention and may be combined with other known technologies or may be partially omitted or changed without departing from the scope of the present invention. List of reference symbols

[0056] 10 switching device; 11 link state database; 12, 32 routing unit; 13, 33 priority adaptation unit; 20 terminal device; 30 adaptation device; 31 input unit; 34 output unit; 121, 321 shortest path calculation unit; 122, 322 path selection unit.

Claims

[1] Transmission device (10) which is one of transmission devices (10) forming a network, the transmission device (10) comprising: an information holding unit (11) for holding topology information of the network, and priority of the transmission device (10) and priorities of other transmission devices (10) constituting the network, to be used in path calculation; a shortest path calculation unit (121) for calculating a shortest path from a first transmission device (10) to a second transmission device among the transmission devices (10) constituting the network on the basis of the topology information; and a priority adjustment unit (13) for adjusting the priority of the transmission device (10) on the basis of the shortest path calculated by the shortest path calculation unit (121) and the priority of the transmission device (10) and the priorities of the other transmission devices (10), wherein the priority adjustment unit (13) adjusts the priority of the transmission device (10) so that the number of overlaps with priority of another transmission device (10) arranged with the transmission device (10) in a shortest path from a starting point to a destination and at the same distance from the starting point as the transmission device (10) is reduced. [2] The transmission device (10) according to claim 1, wherein the priority adjustment unit (13) performs a process of provisionally determining the priority of the transmission device (10) to one of possible values and evaluating the provisionally determined priority based on information about a shortest path between a first transmission device and a second transmission device, the first transmission device and the second transmission device being any two of the transmission devices (10) constituting the network, the priority of the transmission device (10), and the priorities of the other transmission devices (10), the priority adjustment unit (13) performing the process on each of the possible values, and the priority adjustment unit (13) determines the priority of the transmission device (10) based on results,obtained by performing an evaluation on each of the possible values provisionally determined as the priority., [3] The transmission device (10) according to claim 2, wherein the priority adjustment unit (13) performs, on each of the groups of transmission devices (10) having the same destination and at the same distance from a starting point, a process of obtaining an exclusive OR (XOR) of the priorities of each of the pairs of transmission devices (10) belonging to the group, further extracting four bits satisfying a preset condition from the results of the exclusive OR operations of the respective pairs, changing '1' of the extracted four bits, except for the most significant bits '1', to '0', and performing an OR operation on the changed four bits to generate a first operation result, and then comparing the first operation results between groups of transmission devices (10) having the same destination but different distances from a starting point,to generate a second operation result as an evaluation result of the preliminarily determined priority., [4] The transmission device (10) according to claim 3, wherein, in extracting the four bits satisfying the preset condition from the results of the exclusive OR operations, the priority adjusting unit (13) checks a state of four higher bits of the results of the exclusive OR operations and extracts four bits including a bit set to '1' when four bits including the bit set to '1' are detected, and in comparing the first operation results between the groups of transmission devices (10) having the same destination but different distances from a start point, the priority adjusting unit (13) determines the number of intersections of positions of bits set to "1" as the second operation result. [5] Adjustment means (30) for adjusting a parameter set for each transmission device forming a network, the adjustment means (30) comprising: an information acquisition unit (31) for acquiring topology information of the network and priorities of the transmission devices, the priorities being the parameters used in the path calculation; a shortest path calculation unit (321) for calculating a shortest path from a first transmission device to a second transmission device among the transmission devices based on the topology information; and a priority adjustment unit (33) for adjusting the priorities of the transmission devices on the basis of the shortest path calculated by the shortest path calculation unit (321) and the priorities of the transmission devices, wherein the priority adjustment unit (33) repeats a first process of selecting any one of the transmission devices as a transmission device to be adjusted, and a second process of adjusting the priority of the transmission device to be adjusted so that the number of overlaps with the priority of another transmission device that is arranged with the transmission device to be adjusted in a shortest path from a starting point to a destination and is located at the same distance from the one starting point as the transmission device to be adjusted is reduced, while changing a transmission device selected as the transmission device to be adjusted in the first process. [6] The adjustment device (30) according to claim 5, further comprising: a display unit (34) for displaying a result of adjustment obtained by the priority adjustment unit (33). [7] Adaptation device (30) according to claim 5 or 6, further comprising: a transmitting unit (34) for transmitting a result of the adaptation obtained by the priority adaptation unit (33) to the transmitting devices. [8] A parameter adjustment method for a transmission device (10) to adjust parameters, the transmission device (10) being one of transmission devices (10) forming a network, the parameter adjustment method comprising: a shortest path calculation step of calculating a shortest path from a first transmission device to a second transmission device among the transmission devices (10) constituting the network on the basis of the topology information of the network; and a priority adjustment step of adjusting the priority of the transmission device (10) on the basis of the shortest path calculated in the shortest path calculation step and the priorities of the transmission devices (10) forming the network, wherein in the priority adjustment step, the priority of the transmission device (10) is adjusted so that the number of overlaps with priority of another transmission device (10) which is arranged with the transmission device (10) in a shortest path from a starting point to a destination and at the same distance from the starting point as the transmission device (10) is reduced. [9] A parameter adjustment method for an adjustment device (30) for adjusting a parameter set for each of the transmission devices constituting a network, the parameter adjustment method comprising: an information acquisition step of acquiring topology information of the network and priorities of the transmission devices, the priorities being parameters to be used in the path calculation; a shortest path calculation step of calculating a shortest path from a first transmission device to a second transmission device among the transmission devices based on the topology information; and a priority adjustment step of adjusting the priorities of the transmission devices based on the shortest path calculated in the shortest path calculation step and the priorities of the transmission devices, wherein The priority adjustment step includes: a first step of selecting any one of the transmission devices as a transmission device to be adapted; and a second step of adjusting the priority of the transmission device to be adjusted so that the number of overlaps with the priority of another transmission device that is arranged with the transmission device to be adjusted in a shortest path from a starting point to a destination and is at the same distance from a starting point as the transmission device to be adjusted is reduced, and the first step and the second step are repeated while a transmission device selected as the transmission device to be adjusted in the first step is changed.

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