Diagnostic system, diagnostic device, and diagnostic method

Abstract

The present invention relates to a diagnostic system, a diagnostic device, and a diagnostic method that efficiently perform diagnosis of a network having a mesh structure. This diagnostic system is a diagnostic system for a network that has a transmission node, a reception node, and a diagnostic device, and that transmits a frame from the transmission node to the reception node using a plurality of paths that are independent from each other, said diagnostic system being configured such that the frame is transmitted from the transmission node to the reception node regardless of whether or not some of the plurality of paths are obstructed. Each of the transmission nodes transmits a plurality of frames destined for the same reception node to a plurality of paths, the reception nodes measure the arrival time of each of the plurality of frames received from the same transmission node on the basis of a timer, and notify a diagnostic device of the measurement results, and the diagnostic device determines the arrival time of the plurality of frames on the basis of the measurement results. The present invention diagnoses the time required for the reconstruction of a communication path of a network when an obstacle has occurred and the performance of the network after the reconstruction.

Description

Technical Field

[0001] The present invention relates to a diagnostic system, a diagnostic device and a diagnostic method. Background Art

[0002] To prevent network equipment failures, network paths are made redundant. For example, in Patent Document 1, two Ethernet switches are connected using two loops. During normal operation, communication is performed using either loop. If the loop abnormality detection circuit in the Ethernet switch detects an abnormality in the active loop, it switches the loop to another loop and switches the path.

[0003] In Patent Document 1, it takes a finite time for the loop abnormality detection circuit to detect an abnormality, and switching of the path also takes time, so that information transmission is interrupted.

[0004] For example, there is Non-Patent Document 1 to address the issues raised in Patent Document 1. In Non-Patent Document 1, redundant ring paths are provided, achieving redundancy in the communication path. Consequently, in Non-Patent Document 1, communication frames are sent to the destination from both directions of the ring. Therefore, even if an anomaly occurs in the path on one side, the communication frame from the other side arrives at the destination without delay, thus preventing interruption in information transmission.

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2018-45399

[0006] Non-Patent Literature 1: Industrial Ethernet Rings: PROFINet MRP and MRPD [retrieved February 1, 2017], Internet

[0007] URL: https: / / www.hms-networks.com / news-and-insights / blog / posts / iot-blo

[0008] g / 2018 / 06 / 11 / industrial-ethernet-rings-profinet-mrp-and-mrpd> Summary of the Invention

[0009] The ring topology described in Non-Patent Document 1 generates transmission delays at each node, making it difficult to apply to large-scale systems with a large number of nodes. Furthermore, most common Ethernet system topologies utilize mesh structures, which reduces the degree of freedom in system construction compared to ring topologies.

[0010] Therefore, even when a mesh-structured topology is used, it is preferable to diagnose the network so as not to cause interruption of information transmission.

[0011] Regarding network diagnostics, obtaining information from multiple network switches would allow confirmation of the paths along which communication frames flow, but this requires a complex process and is not practical. Furthermore, if a failure occurs somewhere in the network, rerouting communication frames along the mesh structure and using alternative paths is often difficult. However, it is difficult to verify whether the mesh topology has the redundancy required for reconstruction, the time lost during reconstruction, and the impact of traffic congestion caused by reconstruction.

[0012] In one aspect, an object is to provide a diagnostic system, a diagnostic device, and a diagnostic method capable of efficiently performing a diagnosis of a mesh-structured network.

[0013] One aspect involves a diagnostic system for a network, which has a sending node, a receiving node, and a diagnostic device. Frames are sent from the sending node to the receiving node using multiple independent paths. Regardless of whether an obstruction occurs in some of the multiple paths, the sending node sends multiple frames with the same receiving node as the destination to the multiple paths. The receiving node measures the arrival time of the multiple frames received from the same sending node based on a timer, and notifies the diagnostic device of the measurement results. Based on the measurement results, the diagnostic device diagnoses the time required to reconstruct the communication path of the network when the obstruction occurs and the performance of the network after the reconstruction.

[0014] One aspect of the present invention relates to a diagnostic device comprising: a collection unit that collects arrival time measurement results from a receiving node that receives multiple frames sent from the same sending node, regardless of whether a failure occurs in some of the multiple independent paths included in the network; and a diagnostic processing unit that diagnoses, based on the measurement results, the time required to reconstruct the communication path of the network when a failure occurs and the performance of the network after the reconstruction.

[0015] One aspect involves a diagnostic method for a network, wherein the network has a sending node, a receiving node, and a diagnostic device, and frames are sent from the sending node to the receiving node using multiple independent paths. Regardless of whether an obstruction occurs in some of the multiple paths, the sending node sends multiple frames with the same receiving node as the destination to the multiple paths. The receiving node measures the arrival time of the multiple frames received from the same sending node based on a timer, and notifies the diagnostic device of the measurement results. The diagnostic device diagnoses the time required to reconstruct the communication path of the network when the obstruction occurs and the performance of the network after the reconstruction based on the measurement results.

[0016] Effects of the Invention

[0017] According to one embodiment, it is possible to efficiently perform diagnosis of a network having a mesh structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a diagram for explaining a network with a double-tree structure.

[0019] Figure 2 This is a diagram for explaining a network having a mesh structure.

[0020] Figure 3 It is a diagram showing a diagnostic system according to this embodiment.

[0021] Figure 4 This is a diagram for explaining processing of the diagnostic device.

[0022] Figure 5 This is a diagram showing an example of the data structure of the first measurement result table.

[0023] Figure 6 This is a diagram showing an example of the data structure of the second measurement result table.

[0024] Figure 7 This is a diagram showing an example of the data structure of the system vulnerability table.

[0025] Figure 8 This is a functional block diagram showing the configuration of the diagnostic device according to this embodiment.

[0026] Figure 9 This is a flowchart showing the processing flow of the diagnostic device according to this embodiment.

[0027] Figure 10 This is a diagram showing an example of a plurality of logically independent networks.

[0028] Figure 11 This is a diagram illustrating an example of a hardware configuration. DETAILED DESCRIPTION

[0029] Below, embodiments of the diagnostic system, diagnostic device, and diagnostic method disclosed in this application are described in detail based on the accompanying drawings. The present invention is not limited to these embodiments. Identical elements are denoted by the same reference numerals, and duplicate descriptions are omitted as appropriate. The various embodiments may be appropriately combined within the scope of non-contradiction.

[0030] (Implementation Method)

[0031] (Network with a mesh structure)

[0032] Before describing this embodiment, an example of a network related to a mesh structure will be described. Figure 1For example, the network N1 includes DCNs (Distributed Compute Nodes) 10a, 10b, 10c, 10d, and 10e, DPX adapters 11a, 11b, 11c, 11d, and 11e, HUBs 20 and 30, and a setting unit 40.

[0033] DCNs 10a to 10e are connected to DPX adapters 11a to 11e, respectively. DPX adapters 11a to 11e are connected to HUBs 20 and 30, respectively. DCNs 10a to 10e are collectively referred to as "DCN 10" as appropriate. DPX adapters 11a to 11e are collectively referred to as "DPX adapter 11" as appropriate.

[0034] The DCN 10 outputs data received from, for example, an input device, a control device, etc. to the DPX adapter 11 .

[0035] When the DPX adapter 11 receives data from the DCN 10 , it transmits communication frames to multiple paths. When the DPX adapter 11 receives communication frames from multiple paths, it selects any one communication frame and outputs the data of the selected communication frame to the DCN 10 .

[0036] HUBs 20 and 30 are network switches. Network N1 includes a communication path through HUB 20 and a communication path through HUB 30. Furthermore, a setup unit 40 is connected to HUB 20. This setup unit 40 performs various settings for DCN 10 and other devices via HUB 20. Unlike communication within DCN 10, communication between setup unit 40 and DCN 10 does not require high reliability. For example, if HUB 20 fails, setup unit 40 can simply connect to HUB 30 instead of HUB 20.

[0037] For example, when the DPX adapter 11b receives data from the DCN 10b, two identical communication frames are generated. The DPX adapter 11b transmits one communication frame to the DPX adapter 11c via the HUB 20 and transmits the other communication frame to the DPX adapter 11c via the HUB 30.

[0038] If the DPX adapter 11 c receives two communication frames using a plurality of paths, it selects any one of the communication frames and outputs the data of the selected communication frame to the DCN 10 c.

[0039] about Figure 1The network N1 described in the preceding text has advantages different from the ring structure. For example, as advantages, (1) the wiring freedom and intuitiveness are higher than the ring structure, (2) there is no external interference when inserting or deleting communication nodes, (3) there is no concern about failures caused by simultaneous disconnection of two parts of the ring, and (4) the ring master function required by MRP (Media Redundancy Protocol) is not required. In addition, Figure 1 The case of two communication paths (dual-tree) is described above, but it can also be n (n is a natural number greater than or equal to 3). For example, a triple-tree configuration does not reduce reliability, and the HUB can be replaced one at a time.

[0040] exist Figure 1 The HUB20, 30 described in the description can be Figure 2 A network is shown in which multiple network switches are connected in a mesh configuration. Figure 2 This is a diagram for explaining a mesh network.

[0041] like Figure 2 As shown, for example, network N2 includes DCNs 10a to 10e and DPX adapters 11a to 11e. Network N2 includes SWs 20-1, 20-2, 20-3, 20-4, 20-5, and 20-6. Network N2 also includes SWs 30-1, 30-2, 30-3, 30-4, 30-5, and 30-6.

[0042] About DCN10a~10e, DPX adapter 11a~11e, and use Figure 1 The same description is given for DCN 10a to 10e and DPX adapters 11a to 11e. SW20-1 to 20-6 and SW30-1 to 30-6 are network switches (Ethernet switches), etc. Figure 2 Although SW20-1 to SW20-6 and SW20-1 to SW20-6 are depicted as completely symmetrical, this is not necessarily the case. An asymmetric system can also be formed by using more SW20 switches than SW30 switches to transmit information through multiple layers.

[0043] For example, the DPX adapters 11a and 11b are connected to the SWs 20-1 and 30-1, and the DPX adapters 11c, 11d, and 11e are connected to the SWs 20-3 and 30-3.

[0044] SWs 20-1 through 20-6 communicate data according to a specified communication protocol and pre-establish optimal routing information. SWs 20-1 through 20-6 transmit communication frames based on this established routing information. For example, if SW 20-1 receives a communication frame from DPX adapter 11b addressed to DPX adapter 11c, the communication frame passes through SWs 20-1, 20-2, and 20-3 before reaching DPX adapter 11c.

[0045] When a failure occurs in any of the SWs 20 - 1 to 20 - 6 , the route information is reconstructed.

[0046] SWs 30-1 through 30-6 communicate data according to a specified communication protocol and pre-establish optimal routing information. SWs 30-1 through 30-6 transmit communication frames based on this established routing information. For example, if SW 30-1 receives a communication frame from DPX adapter 11b addressed to DPX adapter 11c, the communication frame passes through SWs 30-1, 30-2, and 30-3 before reaching DPX adapter 11c.

[0047] When a failure occurs in any of the SWs 30 - 1 to 30 - 6 , the route information is reconstructed.

[0048] In addition, Figure 2 In the illustrated example, SWs 20 - 1 to 20 - 6 and SWs 30 - 1 to 30 - 6 are shown, but other SWs may be included.

[0049] The above describes a dual-tree network and a mesh network.

[0050] (Diagnostic System)

[0051] Next, an example of a diagnostic system according to this embodiment will be described. Figure 3 : is a diagram showing a diagnostic system according to this embodiment. Figure 3 As shown, the diagnostic system S1 includes DCNs 10 a to 10 e , DPX adapters 51 a , 51 b , 50 c , 50 d , and 51 e , SWs 20 - 1 to 20 - 6 and 30 - 1 to 30 - 6 , and a diagnostic device 100 .

[0052] DCN10a~10e are connected to DPX adapters 51a~51e respectively. For example, DPX adapters 51a and 51b are connected to SW20-1 and 30-1. DPX adapters 51c, 51d, and 51e are connected to SW20-3 and 30-3. Figure 3 Although the connection relationship is omitted in the figure, the diagnostic device 100 is connected to SW20 or SW30, and is connected to both (SW20, SW30) as appropriate.

[0053] Depicted as physically separate networks Figure 3 The network constructed by SW20-1 to 20-6 and the network constructed by SW30-1 to 30-6 described in the preceding text are described. For example, the network of the diagnostic system S1 is a dual-tree network. Furthermore, as long as the network constructed by SW20-1 to 20-6 and the network constructed by SW30-1 to 30-6 are independent, they can be physically or logically independent.

[0054] The DCNs 10a to 10e are collectively referred to as "DCN 10" as appropriate. The DPX adapters 51a to 51e are collectively referred to as "DPX adapter 51" as appropriate.

[0055] SWs 20-1 through 20-6 communicate data according to a specified communication protocol and pre-establish optimal routing information. SWs 20-1 through 20-6 transmit communication frames based on this established routing information. For example, if SW 20-1 receives a communication frame from DPX adapter 51b addressed to DPX adapter 51c, the communication frame passes through SWs 20-1, 20-2, and 20-3 before reaching DPX adapter 51c.

[0056] Regarding SW20-1 to 20-6, when a failure occurs in any of SW20-1 to 20-6, data communication is performed and path information is reconstructed.

[0057] SWs 30-1 through 30-6 communicate data according to a specified communication protocol and pre-establish optimal routing information. SWs 30-1 through 30-6 transmit communication frames based on this established routing information. For example, if SW 30-1 receives a communication frame from DPX adapter 51b addressed to DPX adapter 51c, the communication frame passes through SWs 30-1, 30-2, and 30-3 before reaching DPX adapter 51c.

[0058] Regarding the SWs 30 - 1 to 30 - 6 , when a failure occurs in any of the SWs 30 - 1 to 30 - 6 , data communication is performed and the route information is reconstructed.

[0059] The DCN 10 is a communication node that requires high data exchange reliability and outputs data received from, for example, an input device or a control device to the DPX adapter 51 .

[0060] When the DPX adapter 51 receives data from the DCN 10, it sends the same communication frame to multiple paths. Figure 3In the example shown, the multiple paths include: a path constructed by SW20-1 to 20-6; and a path constructed by SW30-1 to 30-6. In addition, if the DPX adapter 51 receives communication frames from multiple paths, it selects any one communication frame and outputs the data of the selected communication frame to the DCN 10.

[0061] In the following description, a communication frame using the path established by SWs 20-1 to 20-6 will be referred to as a "first communication frame." A communication frame using the path established by SWs 30-1 to 30-6 will be referred to as a "second communication frame." Furthermore, unless a distinction is made between the first and second communication frames, they will be referred to as a "communication frame."

[0062] The DPX adapter 51 also includes a “timer” that measures the time difference between the arrival of communication frames received from multiple paths. The DPX adapter 51 discloses (transmits) the measurement result of the timer to the diagnostic apparatus 100 .

[0063] The diagnostic device 100 is a device that performs network diagnosis of the diagnostic system S1 . Figure 4 This is a diagram for explaining the processing of the diagnostic device. The diagnostic device 100 selects a SW suspected of having a failure and a port having a failure among the SWs 20-1 to 20-6 and 30-1 to 30-6.

[0064] exist Figure 4 In the example of FIG, the diagnostic apparatus 100 selects SW 30-2 as the SW suspected of having a failure. In addition, as an example, the DPX adapter 51b transmits a communication frame to the DPX adapter 51c.

[0065] For example, the diagnostic device 100 executes a process of suspecting the occurrence of a failure and a process of collecting arrival time difference information.

[0066] The following describes how diagnostic device 100 handles a suspected fault. For example, diagnostic device 100 sends a control signal to SW 30-2 indicating a suspected fault. Specifically, it disables a specific port on SW 30-2. This disconnects the path between SW 30-2 and SW 30-3, for example. If SWs 30-1 to 30-6 detect the disconnection, they rebuild the path information.

[0067] The following describes a process for collecting arrival time difference information by diagnostic apparatus 100. Here, an example will be described in which DPX adapter 51b transmits a communication frame to DPX adapter 51c, and DPX adapter 51c discloses measurement results to diagnostic apparatus 100.

[0068] For example, the DPX adapter 51b transmits the communication frame to the SW20-1 and SW30-1. The DPX adapter 51 on the transmitting side is an example of a "transmitting node." In the following description, the DPX adapter on the transmitting side is appropriately referred to as a transmitting node.

[0069] The DPX adapter 51c receives the first and second communication frames from the DPX adapter 51b, measures the time difference between the time the first and second communication frames are received, and discloses the measurement results to the diagnostic device 100. The measurement results are assigned information identifying the sending node that sent the communication frame and the receiving node (this DPX adapter 51c) based on the time difference information. The receiving DPX adapter 51b is an example of a "receiving node." In the following description, the receiving DPX adapter will be referred to as the receiving node. Furthermore, if the DPX adapter 51c fails to receive either the first or second communication frame, a time limit (time-up) is set for the measurement results.

[0070] Before a suspected fault occurs, the diagnostic device 100 obtains a measurement result (arrival time difference before fault setting) from the DPX adapter 51c and registers the relationship between the transmitting node (e.g., the DPX adapter 51b), the receiving node (the DPX adapter 51c), and the arrival time difference before fault setting in the first measurement result table 141. Similarly, each time the diagnostic device 100 obtains a measurement result from another receiving node, it repeatedly registers the relationship between the transmitting node, the receiving node, and the arrival time difference before fault setting in the first measurement result table 141. For example, the arrival time difference before fault setting corresponds to the first time difference.

[0071] Figure 5 : is a diagram showing an example of the data structure of the first measurement result table. Figure 5 As shown, the first measurement result table 141 registers the time difference before failure setting for the pair of the transmitting node and the receiving node. For example, the time difference before failure setting for the pair of the transmitting node 51a (same as the DPX adapter 51a) and the receiving node 51c (same as the DPX adapter 51c) is shown as "TDac0".

[0072] Next, after a suspected failure occurs, the diagnostic device 100 obtains the measurement results (alternative path establishment time) from the DPX adapter 51c and registers the relationship between the sending node (e.g., DPX adapter 51b), the receiving node (DPX adapter 51c), and the alternative path establishment time in the second measurement result table 142. Similarly, the diagnostic device 100 repeatedly performs the process of obtaining measurement results from other receiving nodes and registering the relationship between the sending node, the receiving node, and the alternative path establishment time in the second measurement result table 142.

[0073] Furthermore, after a suspected failure occurs and after the path information is reconstructed, the diagnostic device 100 obtains the measurement results (time difference after failure setting) from the DPX adapter 51c and further registers the relationship between the sending node (e.g., DPX adapter 51b), the receiving node (DPX adapter 51c), and the time difference after failure setting in the second measurement result table 142. Similarly, the diagnostic device 100 repeatedly obtains measurement results from other receiving nodes and registers the relationship between the sending node, the receiving node, and the time difference after failure setting in the second measurement result table 142. For example, the time difference after failure setting corresponds to the second time difference.

[0074] Figure 6 : is a diagram showing an example of the data structure of the second measurement result table. Figure 6 As shown, the second measurement result table 142 registers the arrival time difference after the obstacle setting and the alternative path establishment time for the pair of the transmission node and the receiving node. For example, the alternative path establishment time for the pair of the transmission node 51a (same as the DPX adapter 51a) and the receiving node 51c (same as the DPX adapter 51c) is "TRac" and the arrival time difference after the obstacle setting is "TDac1".

[0075] The diagnostic device 100 performs diagnostic processing based on the first measurement result table 141 and the second measurement result table 142, registering the diagnostic results in the system vulnerability table 143. For example, if the alternative path construction time is long (longer than a pre-defined time), or if a failure occurs in the selected SW, the diagnostic device 100 diagnoses that "alternative path cannot be constructed" or "alternative path construction time is too long." More specifically, if a time limit is set for measurement results from the receiving node, the diagnostic device 100 diagnoses that the alternative path cannot be constructed if the time limit persists. If the time limit persists for a long time (i.e., the alternative path construction time is long), the diagnostic device 100 diagnoses that the alternative path construction time is too long.

[0076] If the difference between the arrival time difference before and after the obstacle is set is large (greater than a preset threshold), the diagnostic device 100 diagnoses that the performance variation after the alternative path is established is excessive. The diagnostic device 100 associates the sending node, the receiving node, and the diagnostic result and registers them in the system vulnerability table 143. The diagnostic device 100 then resolves the suspected obstacle.

[0077] The diagnostic device 100 changes the SW and port where a suspected failure has occurred and repeatedly executes the above-mentioned process.

[0078] Figure 7 This is a diagram showing an example of the data structure of the system vulnerability table. Figure 7 As shown, system vulnerability table 143 includes diagnostic results for suspected failures in each SW. For example, if a failure occurs in SW20-2 (Port 4), the pair of transmission node 51a (same as DPX adapter 51a) and reception node 51d (same as DPX adapter 51d) is diagnosed as taking too long to establish an alternative path. Furthermore, if a failure occurs in SW20-2 (Port 4), the pair of transmission node 51a (same as DPX adapter 51a) and reception node 51d (same as DPX adapter 51d) is diagnosed as experiencing excessive performance variations after establishing an alternative path.

[0079] (Functional Structure of Diagnostic Device 100)

[0080] Next, a configuration example of the diagnostic device 100 according to this embodiment will be described. Figure 8 FIG. 1 is a functional block diagram showing the structure of the diagnostic device according to the present embodiment. Figure 8 As shown, diagnostic device 100 includes a communication unit 110, an input unit 120, a display unit 130, a storage unit 140, and a control unit 150. Furthermore, the functional units of diagnostic device 100 are not limited to those shown in the figure and may include other functional units. Furthermore, diagnostic device 100 may be implemented by multiple server computers.

[0081] The communication unit 110 performs data communication with the DPX adapters 51a to 51e, and the SWs 20-1 to 20-6 and 30-1 to 30-6.

[0082] The input unit 120 inputs various information to the control unit 150 of the diagnostic apparatus 100. The input unit 120 is a keyboard, a mouse, a touch panel, or the like.

[0083] The display unit 130 displays information output from the control unit 150 of the diagnostic apparatus 100 .

[0084] The storage unit 140 stores a first measurement result table 141, a second measurement result table 142, and a system vulnerability table 143. The storage unit 140 is implemented by a memory, a hard disk, or the like.

[0085] Explanation and Use of the First Measurement Result Table 141, the Second Measurement Result Table 142, and the System Vulnerability Table 143 Figures 5-6 The same instructions are performed.

[0086] The control unit 150 is a processing unit that manages the entire diagnostic apparatus 100 and is implemented by, for example, a processor, etc. The control unit 150 includes a failure occurrence processing unit 151 , a collection unit 152 , and a diagnosis processing unit 153 .

[0087] The fault processing unit 151 selects a suspected faulty SW (and port) and sends a suspected faulty control signal to the selected SW. After completing the diagnosis associated with the suspected faulty SW, the fault processing unit 151 resolves the suspected fault in the SW and switches the suspected faulty SW.

[0088] The failure processing unit 151 may randomly select a SW suspected of having a failure, or may select a SW based on a priority. For example, the priority of each SW may be set to a preset priority.

[0089] Other processing and utilization performed by the fault generation processing unit 151 Figure 4 The same treatment shall apply to suspected obstructions as described above.

[0090] Before a suspected failure occurs in the SW, the collector 152 obtains measurement results (time differences before failure) from each receiving node and registers the relationship between the transmitting node, receiving node, and time differences before failure in the first measurement result table 141 .

[0091] After a suspected failure occurs in the SW, the collecting unit 152 obtains measurement results (alternative path construction time) from each receiving node and registers the relationship between the transmitting node, the receiving node, and the alternative path construction time in the second measurement result table 142 .

[0092] After a suspected obstacle occurs and the path information is reconstructed, the collection unit 152 obtains measurement results (arrival time difference after obstacle setting) from each receiving node, and further registers the relationship between the sending node, receiving node, and arrival time difference after obstacle setting in the second measurement result table 142.

[0093] The diagnosis processing unit 153 executes a diagnosis process based on the first measurement result table 141 and the second measurement result table 142 , and registers the diagnosis result in the system vulnerability table 143 .

[0094] For example, the diagnostic processing unit 153 selects a pair of transmitting and receiving nodes. If the alternative path construction time for the selected pair is long (longer than a predetermined time), or if a failure occurs in the corresponding SW (and port), the diagnostic processing unit 153 diagnoses that the alternative path cannot be constructed or that the time required is too long. For example, if a time limit is set for the measurement results, the diagnostic processing unit 153 diagnoses that the alternative path cannot be constructed. If the alternative path construction time is long, the diagnostic processing unit 153 diagnoses that the alternative path construction time is too long.

[0095] If the difference between the arrival time difference before the obstacle is set and the arrival time difference after the obstacle is set is large (larger than a preset threshold), the diagnosis processing unit 153 diagnoses that the performance change after the alternative route is constructed is excessive.

[0096] The collecting unit 152 and the diagnostic processing unit 153 repeatedly execute the above-mentioned process each time the SW (and port) suspected of having a failure is switched. The diagnostic processing unit 153 can output the diagnostic results registered in the system vulnerability table 143 to the display unit 130 for display.

[0097] (Processing Flow)

[0098] Next, the processing flow of the diagnostic apparatus 100 according to this embodiment will be described. Figure 9 Flowchart showing the processing flow of the diagnostic apparatus of this embodiment. Figure 9 As shown, the failure occurrence processing unit 151 of the diagnostic device 100 selects a SW in which a suspected failure has occurred from among the SWs included in the communication path (step S101 ).

[0099] The collection unit 152 of the diagnostic device 100 obtains the fault setting pre-arrival time difference before the occurrence of the suspected fault and registers it in the first measurement result table 141 (step S102). The fault generating unit 151 of the diagnostic device 100 transmits a control signal for generating a suspected fault to the selected SW (step S103).

[0100] The collecting unit 152 acquires the alternative route construction time and registers it in the second measurement result table 142 (step S104 ). The collecting unit 152 acquires the arrival time difference after obstacle setting and registers it in the second measurement result table 142 (step S105 ).

[0101] The diagnostic processing unit 153 executes diagnostic processing based on the first measurement result table 141 and the second measurement result table 142 and registers the diagnostic results in the system vulnerability table 143 (step S106). The diagnostic processing executed by the diagnostic processing unit 153 in step S106 is the same as described above.

[0102] The failure processing unit 151 resolves the failure of the SW that has generated the suspected failure (step S107 ), and proceeds to step S101 .

[0103] (Effect)

[0104] Next, the effect of the diagnostic system S1 involved in this embodiment is described. After a suspected obstruction occurs on a portion of multiple paths with respect to a sending node, the diagnostic system S1 sends multiple communication frames with the same receiving node as the destination to the multiple paths. The receiving node measures the arrival time of multiple frames received from the same sending node based on a timer, and notifies the diagnostic device 100 of the measurement results. Based on the measurement results, the diagnostic device 100 diagnoses the time required to reconstruct the communication path of the network when the suspected obstruction occurs and the performance of the network after the reconstruction. In this way, the diagnosis of the mesh-structured network can be performed efficiently.

[0105] Furthermore, according to the diagnostic system S1, the diagnostic device 100 selects some nodes included in multiple paths and further executes a process for suspected failure on the selected nodes (SW), thereby making it possible to easily diagnose the influence of the failure occurring at each node.

[0106] Furthermore, according to diagnostic system S1, after a suspected failure occurs on one of the multiple paths, the receiving node notifies diagnostic device 100 of the period during which some frames from the same sending node have not arrived, as the alternative path establishment time. Diagnostic device 100 diagnoses the alternative path establishment time as the time required to reestablish the communication path in the network at the time of the suspected failure. This makes it easy to determine the time from the failure occurrence until the communication path is reestablished.

[0107] Before a suspected failure occurs on a portion of the multiple paths, the receiving node notifies the diagnostic device 100 of the difference in arrival times of multiple frames received from the same sending node as a pre-failure arrival time difference. After the suspected failure occurs on a portion of the multiple paths and after the path information is reconstructed, the receiving node notifies the diagnostic device 100 of the difference in arrival times of multiple frames received from the same sending node as a post-failure time difference. Based on the pre-failure arrival time difference and the post-failure time difference, the diagnostic device diagnoses the difference between the arrival times of frames based on the network before the reconstructed network and the arrival times of frames based on the reconstructed network. This allows the performance of the communication path to be determined after the failure occurs and the path is reconstructed.

[0108] In addition, according to the diagnostic system S1, when the receiving node does not receive a frame from a part of the multiple paths, it notifies the diagnostic device 100 of the information that the frame has not been received from a part of the paths. In this way, it is possible to determine the path that cannot be used due to the occurrence of an obstacle. In addition, the setting of suspected obstacles is carried out for the entire network system. At this time, in the description so far, the setting of suspected obstacles is carried out for one part at a time, and then the setting is released for the next part. However, multiple failures can be simulated. That is, settings can be made for multiple parts at the same time. However, if obstacles are set at the same time across two independent networks (in the case of two independent systems), it may be impossible to transmit signals from the sending node to the receiving node, so it is set to avoid such multiple settings. In addition, the diagnostic system S1 also sends and receives frames other than frames with the same receiving node as the destination.

[0109] (Other network structures)

[0110] For example, in using Figure 3 In the examples described above, the network constructed by SW20-1 to 20-6 and the network constructed by SW30-1 to 30-6 are described as physically independent networks, but as long as the network constructed by SW20-1 to 20-6 and the network constructed by SW30-1 to 30-6 are independent, they can be physically independent or logically independent.

[0111] Figure 10 This is a diagram showing an example of multiple logically independent networks. Figure 8 The network shown uses VLAN (Virtual LAN) technology to form multiple logically independent networks. For example, for one VLAN, DPX adapter 11b is connected to SW20-1, and for another VLAN, DPX adapter 11b is connected to SW30-1. In addition, for one VLAN, DPX adapter 11c is connected to SW20-3, and for another VLAN, DPX adapter 11c is connected to SW30-3. If MSTP (Multiple Spanning Tree Protocol) specified in IEC / IEEE 60802 is used and a network switch that supports it is used, it is also possible to achieve the same. Figure 10 Describes the topology.

[0112] (hardware)

[0113] Next, a hardware configuration example of the diagnostic apparatus 100 will be described. Figure 11 This is a diagram illustrating an example of a hardware configuration. Figure 11As shown, the diagnostic device 100 includes a communication device 6a, a HDD (Hard Disk Drive) 6b, a memory 6c, and a processor 6d. Figure 11 The components shown are connected to each other by a bus or the like.

[0114] The communication device 6a communicates with the DPX adapter 11, SW20-1 to 20-6, SW30-1 to 30-6, etc. of the diagnostic system S1. Figure 8 The program that executes the functions shown is stored in the DB.

[0115] Processor 6d will execute the Figure 8 The program for the same processing of each processing unit shown is read from HDD6b and expanded in memory 6c, thereby executing Figure 8 The processes for each function described in [ 15 ] and [ 15 ] are executed. For example, this process performs the same functions as the various processing units in the diagnostic device 100. Specifically, the processor 6 d executes the following process, that is, performs the same processing as the failure occurrence processing unit 151, the collection unit 152, the diagnosis processing unit 153, etc.

[0116] In this manner, the diagnostic device 100 operates as a diagnostic device that performs the information provision method by reading and executing a program. Furthermore, the diagnostic device 100 can also read the program from a recording medium using a media reader and execute the read program, thereby achieving the same functions as the above embodiment. Furthermore, the program described in this other embodiment is not limited to being executed by the diagnostic device 100. For example, the present invention can also be applied to other computers or servers executing the program, or to other computers or servers operating in collaboration to execute the program.

[0117] The program can be distributed via a network such as the Internet. Alternatively, the program can be recorded on a computer-readable recording medium such as a hard disk, floppy disk (FD), CD-ROM, MO (Magneto-Optical disk), or DVD (Digital Versatile Disc), and executed by the computer after reading from the recording medium.

[0118] (other)

[0119] Several examples of combinations of disclosed technical features are described below.

[0120] (1) A network diagnostic system comprising a sending node, a receiving node, and a diagnostic device, wherein a frame is sent from the sending node to the receiving node using a plurality of independent paths, wherein:

[0121] Regardless of whether a portion of the plurality of paths is obstructed, the sending node sends a plurality of frames with the same receiving node as the destination to the plurality of paths.

[0122] The receiving node measures the arrival times of a plurality of frames received from the same sending node using a timer, and notifies the diagnostic device of the measurement results.

[0123] The diagnostic device performs processing for diagnosing, based on the measurement results, the time required to reconstruct the communication path of the network when the failure occurs and the performance of the network after the reconstructing.

[0124] (2) The diagnostic system according to (1), wherein:

[0125] The diagnostic device selects a portion of nodes included in the plurality of paths, and further performs a process of generating a suspected failure on the selected portion of nodes.

[0126] (3) The diagnostic system according to (1) or (2), wherein:

[0127] After a suspected failure occurs in a part of the plurality of paths, the receiving node notifies the diagnostic device of a period during which a part of the plurality of frames from the same sending node do not arrive.

[0128] (4) The diagnostic system according to (3), wherein:

[0129] The diagnostic device diagnoses the period as the time required to reestablish the communication path of the network when the suspected failure occurs.

[0130] (5) The diagnostic system according to any one of (1) to (4), wherein:

[0131] When the frame is not received from a part of the plurality of paths, the receiving node further performs a process of notifying the diagnosis device of the fact that the frame is not received from the part of the paths.

[0132] (6) The diagnostic system according to (3), wherein:

[0133] Before a suspected obstacle occurs in a part of the multiple paths, the receiving node notifies the diagnostic device of the difference in arrival times of multiple frames received from the same sending node as a first time difference. After a suspected obstacle occurs in a part of the multiple paths and after the path information is reconstructed, the receiving node notifies the diagnostic device of the difference in arrival times of multiple frames received from the same sending node as a second time difference.

[0134] (7) The diagnostic system according to (6), wherein:

[0135] The diagnostic device diagnoses a difference between an arrival time of a frame based on the network before the reconstruction and an arrival time of a frame based on the network after the reconstruction based on the first time difference and the second time difference.

[0136] (8) A diagnostic device, wherein:

[0137] The diagnostic device comprises:

[0138] a collecting unit that collects arrival time measurement results from a receiving node that receives a plurality of frames transmitted from the same transmitting node, regardless of whether a failure occurs in a portion of a plurality of independent paths included in the network; and

[0139] A diagnostic processing unit diagnoses, based on the measurement results, a time required to reestablish a communication path of the network when the failure occurs and performance of the network after the reestablishment.

[0140] (9) A method for diagnosing a network, the network comprising a sending node, a receiving node, and a diagnostic device, wherein a frame is sent from the sending node to the receiving node using a plurality of independent paths, wherein:

[0141] Regardless of whether a portion of the plurality of paths is obstructed, the sending node sends a plurality of frames with the same receiving node as the destination to the plurality of paths.

[0142] The receiving node measures the arrival times of a plurality of frames received from the same sending node using a timer, and notifies the diagnostic device of the measurement results.

[0143] The diagnostic device performs processing for diagnosing, based on the measurement results, the time required to reconstruct the communication path of the network when the failure occurs and the performance of the network after the reconstructing.

[0144] Description of the label

[0145] 100 diagnostic devices

[0146] 110 Communications Department

[0147] 120 Input unit

[0148] 130 display unit

[0149] 140 Storage Department

[0150] 141 1st measurement result table

[0151] 142 Second measurement result table

[0152] 150 Control Department

[0153] 151 Obstacle Generation and Processing Department

[0154] 152 Collection Department

[0155] 153 Diagnosis and Processing Department

Claims

1. A network diagnostic system comprising a sending node, a receiving node, and a diagnostic device, wherein a frame is sent from the sending node to the receiving node using a plurality of independent paths, wherein: Regardless of whether a portion of the plurality of paths is obstructed, the sending node sends a plurality of frames with the same receiving node as the destination to the plurality of paths. The receiving node measures the arrival times of a plurality of frames received from the same sending node using a timer, and notifies the diagnostic device of the measurement results. The diagnostic device performs processing for diagnosing, based on the measurement results, the time required to reconstruct the communication path of the network when the failure occurs and the performance of the network after the reconstructing.

2. The diagnostic system according to claim 1, wherein: The diagnostic device selects a portion of nodes included in the plurality of paths, and further performs a process of generating a suspected failure on the selected portion of nodes.

3. The diagnostic system according to claim 2, wherein: After a suspected failure occurs in a part of the plurality of paths, the receiving node notifies the diagnostic device of a period during which a part of the plurality of frames from the same sending node do not arrive.

4. The diagnostic system according to claim 3, wherein: The diagnostic device diagnoses the period as the time required to reestablish the communication path of the network when the suspected failure occurs.

5. The diagnostic system according to claim 1, wherein: When the frame is not received from a part of the plurality of paths, the receiving node further performs a process of notifying the diagnosis device of the fact that the frame is not received from the part of the paths.

6. The diagnostic system according to claim 3, wherein: Before a suspected obstacle occurs in a part of the multiple paths, the receiving node notifies the diagnostic device of the difference in arrival times of multiple frames received from the same sending node as a first time difference. After a suspected obstacle occurs in a part of the multiple paths and after the path information is reconstructed, the receiving node notifies the diagnostic device of the difference in arrival times of multiple frames received from the same sending node as a second time difference.

7. The diagnostic system according to claim 6, wherein: The diagnostic device diagnoses a difference between an arrival time of a frame based on the network before the reconstruction and an arrival time of a frame based on the network after the reconstruction based on the first time difference and the second time difference.

8. A diagnostic device, wherein: The diagnostic device comprises: a collecting unit configured to collect arrival time measurement results from a receiving node that receives a plurality of frames transmitted from the same transmitting node, regardless of whether a failure occurs in a portion of a plurality of independent paths included in the network; as well as A diagnostic processing unit diagnoses, based on the measurement results, a time required to reestablish a communication path of the network when the failure occurs and performance of the network after the reestablishment.

9. A method for diagnosing a network, the network comprising a sending node, a receiving node, and a diagnostic device, wherein a frame is sent from the sending node to the receiving node using a plurality of independent paths, wherein: Regardless of whether a portion of the plurality of paths is obstructed, the sending node sends a plurality of frames with the same receiving node as the destination to the plurality of paths. The receiving node measures the arrival times of a plurality of frames received from the same sending node using a timer, and notifies the diagnostic device of the measurement results. The diagnostic device diagnoses, based on the measurement results, the time required to reconstruct the communication path of the network when the failure occurs and the performance of the network after the reconstructing.

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