JP2017028629A - Verification device and verification method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a verification device capable of detecting a setting error of a node with a small number of packets and a verification method.SOLUTION: A detector 52 detects a node whose route information representing an output destination of an input packet out of a plurality of nodes constituting a network is updated. An extraction part 53 extracts a communication route passing through the detected node from the route information before and after update of the plurality of nodes. A verification part 54 verifies reachability of a test packet sent to the extracted communication route.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a verification apparatus and a verification method.

  In recent years, SDN (Software defined networking) is known as a technique for controlling a communication path of a network. The SDN centrally controls nodes such as network devices constituting the network by software, and enables the network structure, configuration, settings, and the like to be flexibly and dynamically changed. A network service in which a large-scale network composed of a plurality of nodes is logically divided using such a network control technology and a divided area is lent is assumed. For example, a network service in which a plurality of bases of a company are connected by a virtual network, and a network is leased by specifying a bandwidth (demand) between the bases is assumed. In the case of controlling the network in this way, logical design for logically designing the communication path and bandwidth of the network is performed. Then, a logical verification is made that there is no failure in the result of the logical design. As a result of the verification, the network design information that has been logically confirmed to have no failure is converted into the setting information of each node, and the setting information is written into each node. In the node, internal setting is performed by generating internal hardware register information based on the written setting information.

JP 2006-40196 A JP 2007-241865 A

  However, even if setting information converted from network design information that has been confirmed to have no logical failure is written to each node, a communication path and bandwidth as designed may not be secured in the network. For example, in a node, there is a case where a register set in hardware is shifted and a designed communication path and bandwidth cannot be secured due to a problem in firmware that generates register information.

  In order to cope with such a case, a verification method is conceivable in which a test packet is sent to the network to verify whether a communication path and a band according to the logical design can be secured in the network. For example, a verification method that allows test packets to flow only through communication paths that have changed in the logical design is conceivable. However, if a register set in hardware at a node is shifted, settings of other communication paths are changed, which may affect a communication path that does not change the logical design. For this reason, if a test packet is only sent through a communication path that has changed in logical design, there is a possibility that a node setting error may be missed. In addition, for example, a verification method can be considered in which test packets are sent to all communication paths between all start points and end points of a network regardless of logical design contents. However, when test packets are sent to all communication paths, the number of test packets increases and verification takes time.

  An object of one aspect is to provide a verification device and a verification method that can detect a node setting error with a small number of packets.

  In the first proposal, the verification apparatus includes a detection unit, an extraction unit, and a verification unit. The detection unit detects a node in which path information indicating an output destination of the input packet is updated among a plurality of nodes constituting the network. The extraction unit extracts a communication path passing through the node detected by the detection unit from path information before and after updating of the plurality of nodes. The verification unit verifies the reachability of the test packet that is flowed on the communication path extracted by the extraction unit.

  According to one embodiment of the present invention, it is possible to detect a node setting error with a small number of packets.

FIG. 1 is a diagram schematically showing the flow of network design. FIG. 2 is a diagram schematically showing the flow of applying the result of logic design to the network. FIG. 3 is a diagram illustrating an example of a schematic configuration of the entire system. FIG. 4 is a diagram illustrating an example of a functional configuration of the verification apparatus. FIG. 5 is a diagram illustrating an example of a data configuration of a route table of each node. FIG. 6 is a diagram illustrating an example of changing the route table of each node. FIG. 7 is a diagram illustrating an example of a flow for changing the communication path in the logical design. FIG. 8 is a diagram for explaining an example when an abnormality has occurred in the communication path. FIG. 9 is a diagram illustrating an example of a communication path through which a test packet flows by the verification apparatus according to the present embodiment. FIG. 10 is a diagram illustrating an example of a communication path through which a conventional test packet flows. FIG. 11 is a diagram illustrating an example of a communication path through which a conventional test packet flows. FIG. 12 is a timing chart schematically showing the overall flow of communication path verification. FIG. 13 is a flowchart illustrating an example of the procedure of the verification process. FIG. 14 is a diagram illustrating an example of a data configuration of a route table of each node. FIG. 15 is a diagram illustrating a computer that executes a verification program.

  Embodiments of a verification apparatus and a verification method according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. Each embodiment can be appropriately combined within a range in which processing contents are not contradictory.

[Logical design and verification of network]
First, network logic design and logic verification will be described. In recent years, it has become possible for networks to centrally control network devices such as routers and switches constituting the network by software. Thus, there is SDN as a technique related to network control. The SDN uses a device that relays packets, such as a network device constituting a network, as a node, and centrally controls the node by software, so that the structure, configuration, setting, and the like of the network can be flexibly and dynamically changed.

  In SDN, a network user who uses a network can change the network by software. FIG. 1 is a diagram schematically showing the flow of network design. In FIG. 1, a case where a logical design of a network composed of nodes A to F is performed will be described as an example. The network user inputs a demand for the network. For example, the network user inputs a demand for requesting allocation of a communication path and a bandwidth to the network. In the example of FIG. 1, the bandwidth secured in the communication path is shown in a matrix as the demand corresponding to the transmission source and the transmission destination of the communication path. The item “Src” of demand is an area for storing the transmission source of the communication path. The item “Dst” of demand is an area for storing the destination of the communication path. In the example of FIG. 1, Node A, Node B, and Node C, which are end nodes in the network, are set as the source and destination, and the addresses of the respective nodes are also set. For example, “node A: IP_a”, “node B: IP_b”, and “node C: IP_c” are set in the transmission source and the destination. In the areas corresponding to the demand transmission source and destination, a numerical value indicating the bandwidth to be secured is set. The example of FIG. 1 indicates that a band of “100” Mbps is additionally secured between the transmission source “Node A: IP_a” and the destination “Node B: IP_b”. Further, the example of FIG. 1 indicates that a bandwidth of “50” Mbps is additionally secured between the transmission source “node A: IP_a” and the destination “node C: IP_c”. Further, the example of FIG. 1 indicates that a communication path having a bandwidth of “100” Mbps between the transmission source “Node B: IP_b” and the destination “Node C: IP_c” is deleted.

  In logical design, route design is performed according to demand. For example, in the logical design, a path design is performed for each node constituting an actual network according to a demand communication path and a bandwidth. In the example of FIG. 1, “A-D-B; 100 (addition)” indicates that a communication path of 100 Mbps is additionally secured in the paths of node A, node D, and node B. In the example of FIG. 1, a communication path of 50 Mbps is added as the path of node A, node D, node F, node E, and node C as “A-D-F-E-C; 50 (addition)”. Indicates securing. In the example of FIG. 1, “B-E-C; 100 (deletion)” indicates that the communication path of 100 Mbps is deleted in the paths of the node B, the node E, and the node C.

  In the network logical design, network design information is generated according to the path design. For example, in logical design, a route table is generated as design information for each node constituting an actual network. In the logical design, setting information to be set for each node is generated from the design information. For example, in logical design, route table entry information is generated as setting information.

  In this way, when the network can be changed by the network user, inconsistencies and unexpected events occur in the network operation compared to the case where the network provider that provides the network manages all the networks in a unified manner. The possibility increases. For example, there are cases where a packet is not transferred to a transfer destination in the network, or a bandwidth cannot be secured. Therefore, before applying the generated route table to an actual network, logical verification of the validity of the generated route table is performed on software. For example, logical verification is made that there is no failure in the result of the logical design, such as whether the generated route table of each node satisfies the original demand or does not include a mistake. As a result of the verification, a route table that has been confirmed to have no logical failure is applied to the actual network, thereby suppressing inconsistencies and unexpected events in the actual network operation.

[Apply to network]
Next, the flow of applying the logical design result to the network will be described. FIG. 2 is a diagram schematically showing the flow of applying the result of logic design to the network. In the SDN, an SDN controller 10 is provided. The SDN controller 10 is a device that performs various settings for an actual network. The SDN controller 10 is, for example, a computer such as a personal computer or a server computer in which software for the SDN controller is installed.

  The SDN controller 10 receives design information that has been confirmed to have no logical failure. The SDN controller 10 sets a communication path in the path table of each node based on the design information. For example, the SDN controller 10 generates entry information for adding / deleting a communication path from / to the path table of each node from the design information, and stores the entry information in the memory 11A for setting holding of each node. .

  In the node, based on the entry information written in the memory 11A, internal hardware register information is generated and internal setting is performed. For example, in the node, register information is generated from the entry information by the firmware, and a routing setting is added to or deleted from a route table stored in an internal CAM (Content Addressable Memory) 11B. The node routes the packet according to the route table. However, in the node, the register may be shifted due to a problem in firmware or hardware, and data registration or deletion may be performed for different areas of the CAM 11B. As described above, when data is registered or deleted in different areas of the CAM 11B, the path corresponding to the data in the different areas is affected. Thereby, for example, other communication paths that have not changed the logical design may be affected.

  Therefore, a test packet is sent to the network, and it is verified whether a communication path and a bandwidth as per the logical design can be secured in the network.

[System configuration]
Next, the system 20 according to the present embodiment will be described. The system 20 is a system that applies SDN and centrally controls the nodes constituting the actual network 21 by software. FIG. 3 is a diagram illustrating an example of a schematic configuration of the entire system. In the example of FIG. 3, the network 21 includes nodes A to I. Node C is connected to node E by port 0. Node D is connected to node E by port 0. Node E is connected to node C by port 1, connected to node D by port 2, and connected to node F by port 0. Node F is connected to node E through port 2, connected to node A through port 0, and connected to node B through port 1. Node G is connected to node H by port 0. Node H is connected to node G by port 1 and to node I by port 0. Node A, node B, node C, node D, node G, and node I are edge nodes that communicate with the outside. Node E, node F, and node H are relay nodes that relay data from edge nodes.

  The network 21 includes a plurality of test packet transmission / reception devices 22 and a verification device 23. A test packet transmitting / receiving device 22 is connected to each edge node of the network 21. Each test packet transmitting / receiving device 22 is connected to a verification device 23.

  The test packet transmission / reception device 22 is a device that transmits / receives test packets to / from the network 21. For example, the test packet transmission / reception device 22 transmits a test packet to each edge node in response to an instruction from the verification device 23. Further, the test packet transmitting / receiving apparatus 22 notifies the verification apparatus 23 of the reception result of the test packet received from each edge node in response to an instruction from the verification apparatus 23. In this embodiment, the test packet transmission / reception device 22 is connected to the edge node. However, the edge node has a function of transmitting / receiving a test packet according to an instruction from the verification device 23, and functions as the test packet transmission / reception device 22. May be.

  The verification device 23 is a device that verifies the network 21. The verification device 23 is, for example, a computer such as a personal computer or a server computer. Design information that has been confirmed to have no logical failure is input to the verification device 23. Based on the design information, the verification device 23 controls the test packet transmission / reception device 22 to flow the test packet to the network 21 and verifies whether the communication path according to the logical design can be secured in the network 21.

[Configuration of verification device]
Next, the configuration of the verification device 23 according to the present embodiment will be described. FIG. 4 is a diagram illustrating an example of a functional configuration of the verification apparatus. As illustrated in FIG. 4, the verification device 23 includes a communication I / F (interface) unit 30, an input unit 31, a display unit 32, a storage unit 33, and a control unit 34. Note that the verification device 23 may include devices other than the above devices.

  The communication I / F unit 30 is an interface that controls communication with other devices. As the communication I / F unit 30, a network interface card such as a LAN card can be employed.

  The communication I / F unit 30 transmits / receives various information to / from other devices via a network (not shown). For example, the communication I / F unit 30 receives design information that has been confirmed to have no logical failure and a route table of each node. The design information may be received from the SDN controller 10 or may be received from an apparatus that has performed logic design. The design information may be input from the input unit 31. The route table of each node may be received from the SDN controller 10, may be received from each node, or may be received from an apparatus that has performed logic design. Further, the route table of each node may be input from the input unit 31.

  The input unit 31 is an input device that inputs various types of information. Examples of the input unit 31 include an input device that receives an input of an operation such as a mouse or a keyboard. The input unit 31 receives input of various types of information. For example, the input unit 31 receives various operation inputs related to verification. The input unit 31 receives an operation input from the user and inputs operation information indicating the received operation content to the control unit 34.

  The display unit 32 is a display device that displays various types of information. Examples of the display unit 32 include display devices such as an LCD (Liquid Crystal Display) and a CRT (Cathode Ray Tube). The display unit 32 displays various information. For example, the display unit 32 displays various screens related to verification, such as various operation screens and screens showing verification results.

  The storage unit 33 is a storage device that stores various data. For example, the storage unit 33 is a storage device such as a hard disk, an SSD (Solid State Drive), or an optical disk. Note that the storage unit 33 may be a semiconductor memory that can rewrite data, such as a random access memory (RAM), a flash memory, and a non-volatile static random access memory (NVSRAM).

  The storage unit 33 stores an OS (Operating System) executed by the control unit 34 and various programs. For example, the storage unit 33 stores various programs including programs that execute various processes described later. Furthermore, the storage unit 33 stores various data used in the program executed by the control unit 34. For example, the storage unit 33 stores pre-change route information 41, post-change route information 42, and test route information 43.

  The pre-change route information 41 is data storing information related to the communication route of the network 21 before the change. For example, the pre-change route information 41 stores a pre-change route table of each node constituting the network 21.

  FIG. 5 is a diagram illustrating an example of a data configuration of a route table of each node. The route table 60 is data in which entry information defining a route for transferring a packet of each node is stored. For example, the routing table 60 stores an output destination corresponding to the destination of the packet for each entry information.

  FIG. 5 shows a route table 60 in association with each node. In the present embodiment, only the output destination corresponding to the destination is shown as the entry information in the route table 60 in order to simplify the description. FIG. 5 shows a route table 60 for nodes C, D, E, F, G and H.

  The route table 60 includes items of “table number”, “destination node”, and “output port”. The table number item is an area for storing identification information for identifying a record registered in the route table 60. Identification numbers are assigned to records in the route table 60 in the registered order. In the table number field, an identification number assigned to the record is stored. The item of destination node is an area for storing the destination of the packet. The output port item is an area for storing an output destination corresponding to the destination of the packet. In the route table 60, each record corresponds to entry information. For example, the table number “1” of the node E indicates that the output port of the packet whose destination node is “A” is “0”. Further, the table number “2” of the node E indicates that the output port of the packet whose destination node is “B” is “0”.

  Returning to FIG. 4, for example, the pre-change route information 41 stores a route table 60 of the node C, the node D, the node E, the node F, the node G, and the node H.

  The post-change route information 42 is data storing information related to the changed communication route of the network 21. For example, the post-change route information 42 stores design information that has been confirmed to have no logical failure. The changed route information 42 may store the changed route table 60 of the node whose route table 60 has been changed, or may store entry information for adding or deleting a communication route.

  The test path information 43 is data that stores information related to a communication path to be tested.

  Returning to FIG. 4, the control unit 34 is a device that controls the verification device 23. As the control unit 34, an electronic circuit such as a CPU (Central Processing Unit) and an MPU (Micro Processing Unit), or an integrated circuit such as an ASIC (Application Specific Integrated Circuit) and an FPGA (Field Programmable Gate Array) can be employed. The control unit 34 has an internal memory for storing programs defining various processing procedures and control data, and executes various processes using these. The control unit 34 functions as various processing units by operating various programs. For example, the control unit 34 includes a reception unit 50, an acquisition unit 51, a detection unit 52, an extraction unit 53, a verification unit 54, and an output unit 55.

  The reception unit 50 performs various types of reception. For example, the reception unit 50 receives various operation instructions. For example, the reception unit 50 displays an operation screen related to verification on the display unit 32 and receives an operation instruction such as verification start from the input unit 31. In the present embodiment, an operation instruction such as verification start is received from the input unit 31, but an operation screen may be displayed on another device and the operation instruction may be received remotely from another device. In addition, the reception unit 50 may receive the start of verification that the design information that has been confirmed to have no logical failure has been acquired.

  The acquisition unit 51 performs various acquisitions. For example, the acquisition unit 51 acquires information regarding the communication path of the network 21. For example, the acquisition unit 51 acquires the route table 60 of each node as information on the communication route. The route table 60 of each node may be acquired from the SDN controller 10 or may be acquired from each node. Further, the route table 60 of each node may be acquired at a periodic timing such as a timing for every predetermined period, or may be acquired at an instructed timing. The route table 60 of each node may be transmitted independently by the SDN controller 10 or each node. The acquisition unit 51 requests transmission to each node, and the SDN controller 10 or each node responds to the request. May be transmitted. Further, the route table 60 of each node may be acquired by input from the input unit 31. The acquisition unit 51 stores the route table 60 of each node in the storage unit 33 as the pre-change route information 41.

  For example, the acquisition unit 51 acquires information regarding the communication path of the changed network 21. For example, the acquisition unit 51 acquires design information that has been confirmed to have no logical failure. This design information may be acquired from a device that has performed logical design, or may be acquired from the SDN controller 10. Further, the design information may be acquired by input from the input unit 31. The acquisition unit 51 stores the design information that has been confirmed to have no logical failure in the storage unit 33 as the changed route information 42.

  The detection unit 52 performs various types of detection. For example, the detection unit 52 detects a node in which path information indicating an output destination of an input packet is updated among a plurality of nodes configuring the network 21. For example, when the design information is acquired by the acquisition unit 51, the detection unit 52 detects a node whose path information is updated from the design information. For example, the detection unit 52 detects a node for which addition / deletion of a communication path is specified by design information as a node whose path information has been updated. Thereby, when the design information is changed and the setting information is written to the node, the detection unit 52 detects the node whose path information is updated.

  The extraction unit 53 performs various extractions. For example, the extraction unit 53 extracts a communication route that passes through the node whose route information is updated. For example, the extraction unit 53 identifies the communication route based on the pre-change route table 60 of each node stored in the post-change route information 42 and the pre-change route information 41. For example, the extraction unit 53 extracts the destination of the packet from the route table 60 for each edge node, and when a packet in which the extracted destination is set is input from the edge node, the extraction unit 53 reaches another edge node. The node to be transferred to is obtained using the route table 60 before the change of each node. For example, in the case of FIG. 5, in node C, the destination “A” is extracted. When a packet in which the destination “A” is set is input to the node C, the communication path is specified when the packet is transferred in the order of node C → node E → node F → node A. In node D, the destination “B” is extracted. When a packet in which the destination “B” is set is input to the node D, the communication path is specified when the packet is transferred in the order of node D → node E → node F → node B. Further, in the node G, the destination “I” is extracted. When a packet in which the destination “I” is set is input to the node G, the communication path is specified when the packet is transferred from the node G → the node H → the node I. The extraction unit 53 extracts a communication path including the node in which the path table 60 has been changed, based on the design information acquired by the acquisition unit 51 among the specified communication paths. FIG. 6 is a diagram illustrating an example of changing the route table of each node. The example of FIG. 6 shows an example in which the communication path of node C → node E → node F → node A is deleted. For example, when deleting the communication path of node C → node E → node F → node A, the record of the table number 1 in the path table 60 is deleted in the nodes C, E, and F. In the case of FIG. 6, the extraction unit 53 includes the communication path of the deleted node C → node E → node F → node A and the communication path of node D → node E → node F → node B passing through the nodes E and F. To extract.

  Here, an example of a flow for changing the communication path in the logical design will be described. FIG. 7 is a diagram illustrating an example of a flow for changing the communication path in the logical design. In the example of FIG. 7, in order to simplify the description, a case where logical design is performed on the nodes A to F of the network 21 will be described as an example.

  In the logical design, routing information indicating which ports between the nodes are connected to each other is generated. For example, in the logical design, design information is generated in the form of information in which the destination address and the output port are paired and notified to the SDN controller 10. The node updates internal information based on the setting information converted from the design information. For this reason, the state inside the node cannot be known only by design information.

  In the logical design, addition and deletion of communication paths by demand input are performed in stages. For example, when a route from node C to node A is added due to demand, communication routes of node C, node E, node F, and node A are generated as shown for the first time. For example, in the first design information, node C outputs a packet addressed to A to port 0, node E outputs a packet addressed to A to port 0, and node F outputs a packet addressed to A to port 1. The communication path to be performed is shown. Further, for example, when a route from node D to node B is added due to demand, communication routes of node D, node E, node F, and node B are added as shown in the second time. For example, in the second design information, node D outputs a packet addressed to B to port 0, node E outputs a packet addressed to B to port 0, and node F outputs a packet addressed to B to port 2. The communication path to be performed is shown. Also, for example, when deleting a route from node C to node A due to demand, the communication routes of node C, node E, node F, and node A are deleted from the second time as shown in the third time. For example, in the change from the first time to the second time, the route table 60 is changed in the node D and the node E. Therefore, the extraction unit 53 extracts the communication paths of the nodes C, E, and F along with the communication paths of the added nodes D, E, and F. Further, in the change from the second time to the third time, the route table 60 is changed in the node D and the node E. For this reason, the extraction unit 53 extracts the communication paths of the node D, the node E, and the node F together with the communication paths of the deleted nodes C, E, and F.

  The verification unit 54 performs various verifications. For example, the verification unit 54 verifies the reachability of the test packet that is flowed on the communication path extracted by the extraction unit 53. For example, for each communication path extracted by the extraction unit 53, the verification unit 54 sets a destination corresponding to the communication path for the test packet transmitting / receiving apparatus 22 connected to the upstream edge node of the communication path. Instructs packet transmission. Then, the verification unit 54 sets the destination corresponding to the communication path for the test packet transmitting / receiving apparatus 22 connected to the edge node on the downstream side of the communication path for each communication path extracted by the extraction unit 53. An inquiry is made as to whether a test packet has been received.

  In response to the inquiry from the verification device 23, the test packet transmission / reception device 22 notifies the verification device 23 of the reception result of the test packet.

  For each communication path extracted by the extraction unit 53, the verification unit 54 verifies whether the communication path is valid according to the notification of the packet reception result from the test packet transmitting / receiving apparatus 22. For example, the verification unit 54 determines that the communication path is valid when the reception of the test packet is notified through the added communication path. On the other hand, when the reception of the test packet is not notified on the added communication path, the verification unit 54 determines that an abnormality has occurred in the communication path. The verification unit 54 determines that the communication path is valid when the received communication path is not notified of the reception of the test packet. On the other hand, when the reception of the test packet is notified on the deleted communication path, the verification unit 54 determines that an abnormality has occurred in the communication path. The verification unit 54 determines that the communication path is valid when the reception of the test packet is notified through the existing communication path that passes through the node whose path information is updated and the setting is not changed. On the other hand, the verification unit 54 determines that an abnormality has occurred in the communication path when the reception of the test packet is not notified in the existing communication path passing through the node whose path information is updated.

  The output unit 55 performs various outputs. For example, the output unit 55 outputs the verification result information of the verification unit 54 to the SDN controller 10 and notifies the verification result. For example, the output unit 55 outputs the verification result of the verification unit 54 to the display unit 32.

  Here, an example when an abnormality has occurred in the communication path will be described. FIG. 8 is a diagram for explaining an example when an abnormality has occurred in the communication path. In the example of FIG. 8, in order to simplify the description, description will be made using the nodes A to F of the network 21. In the example of FIG. 8, there are communication paths of node C, node E, node F, and node A, and communication paths of node D, node E, node F, and node B. Node C, node E, and node F are logically designed. The communication path of node A is deleted. In this case, the contents of the node C, the node E, the node F, and the node A change, but in the following, for the sake of simplifying the description, rewriting of the route information of the node E will be mainly described.

  For example, in route design, as a result of logical design, difference information regarding the deleted communication route is generated as design information. For example, the SDN controller 10 is notified as design information of difference information that deletes an entry that outputs a packet of the destination A from the node C to the port 0 and deletes an entry that outputs the packet of the destination A from the node E to the port 0. (FIG. 8 (1)).

  For each node, the SDN controller 10 generates entry information for adding or deleting a communication path in the path table 60 of each node, and stores the entry information in each node. At each node, internal hardware register information is generated based on the entry information, and internal settings are made. For example, in the node A, the record of the destination node “A” and the output port “0” of the table number 1 is deleted. On the other hand, in node E, an erroneous rewrite occurs in the hardware due to a firmware problem or the like, and the record of destination node “B” and output port “0” in table number 2 is deleted (FIG. 5). 8 (2)).

  The verification device 23 acquires the entry information and detects the node E whose path information is updated from the entry information ((3) in FIG. 8). And the verification apparatus 23 extracts the communication path | route which passes along the node by which path | route information was updated ((4) of FIG. 8). In the example of FIG. 8, the verification device 23 extracts the deleted communication paths of the nodes C, E, F, and A and the existing communication paths of the nodes D, E, F, and B.

  The verification device 23 instructs the test packet transmitting / receiving device 22 connected to the node C to transmit the test packet, and causes the test packet to be transmitted to the communication paths of the deleted nodes C, E, F, and A. Further, the verification device 23 instructs the test packet transmission / reception device 22 connected to the node D to transmit the test packet, and transmits the test packet to the existing communication paths of the node D, the node E, the node F, and the node B ( FIG. 8 (5)). In the case of FIG. 8, in the communication paths of the deleted node C, node E, node F, and node A, the entry is deleted at node C, so the test packet does not reach the downstream edge node. Further, in the existing communication paths of the node D, the node E, the node F, and the node B, since the entry is deleted at the node E, the test packet does not reach the downstream edge node.

  The verification device 23 verifies whether the communication path is valid for each communication path based on whether or not the test packet has arrived. In the case of FIG. 8, since the communication paths of the node C, the node E, the node F, and the node A are deleted, it is determined that the test packet does not reach it. On the other hand, since the communication paths of the node D, the node E, the node F, and the node B are not changed in the logical design, it is determined that the test packet does not reach is abnormal. The verification device 23 outputs that a problem has occurred in the communication paths of the node D, the node E, the node F, and the node B.

  FIG. 9 is a diagram illustrating an example of a communication path through which a test packet flows by the verification apparatus according to the present embodiment. In the example of FIG. 9, when the communication paths of the node C, the node E, the node F, and the node A are deleted, the existing node D, the node E, the node F, It is assumed that a problem has occurred in the communication path of Node B.

  According to the verification apparatus 23 according to the present embodiment, a test packet is sent to the communication paths of the nodes C, E, F, and A and the communication paths of the nodes D, E, F, and B. Verification is performed. Therefore, it can be detected that a problem has occurred in the communication paths of the existing nodes D, E, F, and B.

  10 and 11 are diagrams showing an example of a communication path through which a conventional test packet flows. The example of FIG. 10 shows a case where only the deleted node C, node E, node F, and node A are verified by sending test packets. In the example of FIG. 10, it cannot be detected that a problem has occurred in the communication paths of the existing nodes D, E, F, and B.

  The example of FIG. 11 illustrates a case where verification is performed by flowing test packets through all communication paths. In the example of FIG. 11, it can be detected that a problem has occurred in the communication paths of the existing nodes D, E, F, and B. However, since test packets are sent to all communication paths, verification takes time. For example, a large-scale network such as a carrier network of a mobile phone company is composed of a large number of nodes and a large number of communication paths. For this reason, when test packets are made to flow through all communication paths, the number of packets increases and verification takes time, and detection of a node setting error cannot be performed efficiently. On the other hand, since the verification apparatus 23 according to the present embodiment uses only test packets to verify only communication paths that may be affected, node setting errors can be detected with fewer packets.

[Process flow]
First, the overall flow in which the system 20 according to the present embodiment verifies the communication path will be described. FIG. 12 is a timing chart schematically showing the overall flow of communication path verification.

  The verification device 23 acquires information related to the communication path of the network 21 (S10).

  When design information that has been confirmed to have no logical failure is input (S11), the SDN controller 10 stores entry information in each node and sets a communication path based on the design information (S12). ). When the setting is completed, the SDN controller 10 inputs design information to the verification device 23 and requests verification of the communication path (S13).

  The verification device 23 detects the node whose path information is updated from the information on the communication path and the design information, and extracts the communication path passing through the detected node. For each extracted communication path, the verification apparatus 23 instructs the test packet transmitting / receiving apparatus 22 connected to the edge node on the upstream side of the communication path to transmit a test packet in which a destination corresponding to the communication path is set. (S14). The edge node on the downstream side of the communication path notifies whether or not a test packet has been received (S15). For each extracted communication path, the verification apparatus 23 verifies whether the communication path is valid according to the notification of the reception result of the packet from the test packet transmitting / receiving apparatus 22 and outputs the verification result to the SDN controller 10 ( S16).

  In the system 20 according to the present embodiment, the above-described S10 to S16 are performed every time a communication path is added or deleted.

  Next, a verification process flow in which the verification apparatus 23 according to the first embodiment verifies the communication path will be described. FIG. 13 is a flowchart illustrating an example of the procedure of the verification process. This verification process is executed at a predetermined timing, for example, when the design information is input or when a verification start operation instruction is received from the input unit 31.

  As illustrated in FIG. 13, the detection unit 52 detects a node whose path information is updated from the design information (S50). The extraction unit 53 extracts a communication route passing through the node whose route information is updated (S51).

  For each extracted communication path, the verification unit 54 instructs the test packet transmitting / receiving apparatus 22 connected to the edge node on the upstream side of the communication path to transmit a test packet in which a destination corresponding to the communication path is set. (S52). For each extracted communication path, the verification unit 54 has received a test packet in which a destination corresponding to the communication path is set for the test packet transmitting / receiving apparatus 22 connected to the edge node on the downstream side of the communication path. An inquiry about whether or not is made (S53). For each extracted communication path, the verification unit 54 verifies whether the communication path is valid according to the notification of the packet reception result from the test packet transmitting / receiving apparatus 22 (S54).

  The output unit 55 outputs the verification result to the SDN controller 10 (S55), and ends the process.

[effect]
As described above, the verification device 23 according to the present embodiment detects a node in which path information indicating an output destination of an input packet is updated among a plurality of nodes configuring the network 21. The verification device 23 extracts a communication path passing through the detected node from path information before and after updating of the plurality of nodes. The verification device 23 verifies the reachability of the test packet that has been sent to the extracted communication path. As a result, the verification device 23 can detect a node setting error with a small number of packets.

  In addition, when the setting information is written to a plurality of nodes, the verification device 23 according to the present embodiment detects a node whose path information has been updated. Thus, when the setting information is written, the verification device 23 can perform verification and detect a node setting error.

  Although the embodiments related to the disclosed apparatus have been described so far, the disclosed technology may be implemented in various different forms other than the above-described embodiments. Therefore, another embodiment included in the present invention will be described below.

  For example, in the above-described embodiments, the case where the communication path is verified has been described, but the disclosed apparatus is not limited to this. For example, when a band to be secured together with a communication path is designated, it may be verified whether a band can be secured for each communication path. For example, it is assumed that a communication bandwidth to be secured is stored in the route table 60 of each node for each output destination of a packet. FIG. 14 is a diagram illustrating an example of a data configuration of a route table of each node. The path table 60 of each node stores, for each entry information, an output destination corresponding to the packet destination and a communication bandwidth to be secured. In the verification device 23, the extraction unit 53 extracts the communication band of the communication path along with the communication path. The verification unit 54 may further verify whether the extracted communication band is allocated to the extracted communication path of the network 21. For example, the verification unit 54 instructs the test packet transmitter / receiver 22 connected to the edge node on the upstream side of the communication path for each extracted communication path to transmit the test packet with the data amount of the communication band to be secured. To do. In response to an instruction from the verification device 23, the test packet transmitting / receiving device 22 transmits a test packet to the communication path with a data amount of the communication band to be secured. For each extracted communication path, the verification unit 54 determines whether or not a test packet is received with a data amount of a communication band to be secured to the test packet transmitting / receiving apparatus 22 connected to the edge node on the downstream side of the communication path. Make an inquiry. In response to the inquiry from the verification device 23, the test packet transmission / reception device 22 notifies the verification device 23 of the reception result indicating whether or not the test packet having the data amount of the communication band to be secured has been received. The verification unit 54 verifies whether the communication bandwidth to be secured can be secured for each communication path in accordance with the notification of the reception result from the test packet transmitting / receiving apparatus 22 for each extracted communication path. Thereby, the verification apparatus 23 can verify whether the communication band to ensure can be ensured for every communication path.

  In the above-described embodiment, the case where the route table 60 of each node is stored as the pre-change route information 41 has been described. However, the disclosed device is not limited thereto. The pre-change route information 41 may have any data configuration as long as it is information indicating the communication route before the change of the network 21. For example, the pre-change route information 41 may be information indicating a communication route as shown in FIG.

  In the above embodiment, the case where the design information is stored as the changed route information 42 has been described. However, the disclosed apparatus is not limited to this. The post-change route information 42 may be any data configuration as long as it is information indicating the communication route after the change of the network 21. For example, the changed route information 42 may be the route table 60 of each node after the change, or may be information indicating a communication route as shown in FIG.

  In the above-described embodiment, the detection unit 52 has been described for detecting a node whose path information is updated from the design information. However, the disclosed apparatus is not limited thereto. For example, the detection unit 52 may detect a node in which route information is updated from a change in the route table 60 of each node. In this case, the acquisition unit 51 acquires entry information for adding or deleting a communication route from the route table 60 of each node, and stores the entry information in the storage unit 33 as the changed route information 42. This entry information may be acquired from the SDN controller 10. For example, the acquisition unit 51 may monitor the entry information written to each node by the SDN controller 10 and acquire the entry information written from the SDN controller 10 to each node. Further, the entry information may be acquired by input from the input unit 31. The entry information may be acquired from the node. For example, the node in which the entry information is written may be configured to transmit the written entry information to the verification device 23, and the acquisition unit 51 may acquire the entry information from the node. When the acquisition unit 51 acquires entry information, the detection unit 52 detects a node whose path information is updated from the entry information. For example, the detection unit 52 detects a node in which entry information is written as a node in which route information is updated. For example, the detection unit 52 updates the route information by monitoring the writing of the setting information to a plurality of nodes, periodically reading the route information from the plurality of nodes, or notifying from the node in which the route information is updated. Detected nodes. Thereby, when the setting information is written to the node, the detection unit 52 detects the node whose path information is updated.

  Further, each component of each illustrated apparatus is functionally conceptual, and does not necessarily need to be physically configured as illustrated. In other words, the specific state of distribution / integration of each device is not limited to the one shown in the figure, and all or a part thereof may be functionally or physically distributed or arbitrarily distributed in arbitrary units according to various loads or usage conditions. Can be integrated and configured. For example, the processing units such as the reception unit 50, the acquisition unit 51, the detection unit 52, the extraction unit 53, the verification unit 54, and the output unit 55 may be appropriately integrated. Further, the processing of each processing unit may be appropriately separated into a plurality of processing units. Further, all or any part of each processing function performed in each processing unit can be realized by a CPU and a program analyzed and executed by the CPU, or can be realized as hardware by wired logic. .

[Verification program]
The various processes described in the above embodiments can also be realized by executing a program prepared in advance on a computer system such as a personal computer or a workstation. Therefore, in the following, an example of a computer system that executes a program having the same function as in the above embodiment will be described. FIG. 15 is a diagram illustrating a computer that executes a verification program.

  As shown in FIG. 15, the computer 300 includes a CPU (Central Processing Unit) 310, an HDD (Hard Disk Drive) 320, and a RAM (Random Access Memory) 340. These units 300 to 340 are connected via a bus 400.

  The HDD 320 stores in advance a verification program 320a that performs the same functions as the reception unit 50, the acquisition unit 51, the detection unit 52, the extraction unit 53, the verification unit 54, and the output unit 55. Note that the verification program 320a may be separated as appropriate.

  The HDD 320 stores various information. For example, the HDD 320 stores various data used for the OS and analysis.

  Then, the CPU 310 reads out and executes the verification program 320a from the HDD 320, thereby executing the same operation as each processing unit of the embodiment. That is, the verification program 320a performs the same operations as the reception unit 50, the acquisition unit 51, the detection unit 52, the extraction unit 53, the verification unit 54, and the output unit 55.

  Note that the verification program 320a described above does not necessarily need to be stored in the HDD 320 from the beginning.

  For example, the program is stored in a “portable physical medium” such as a flexible disk (FD), a CD-ROM, a DVD disk, a magneto-optical disk, or an IC card inserted into the computer 300. Then, the computer 300 may read and execute the program from these.

  Furthermore, the program is stored in “another computer (or server)” connected to the computer 300 via a public line, the Internet, a LAN, a WAN, or the like. Then, the computer 300 may read and execute the program from these.

DESCRIPTION OF SYMBOLS 10 SDN controller 20 System 21 Network 22 Test packet transmission / reception apparatus 23 Verification apparatus 31 Input part 32 Display part 33 Storage part 34 Control part 41 Pre-change path information 42 Post-change path information 43 Test path information 50 Reception part 51 Acquisition part 52 Detection part 53 Extraction Unit 54 Verification Unit 55 Output Unit 60 Route Table

Claims (5)

A detecting unit for detecting a node in which path information indicating an output destination of an input packet is updated among a plurality of nodes constituting the network;
An extraction unit that extracts a communication path passing through the node detected by the detection unit from the path information before and after the update of the plurality of nodes;
A verification unit that verifies the reachability of the test packet that has been flown through the communication path extracted by the extraction unit;
The verification apparatus characterized by having. The verification device according to claim 1, wherein when the setting information is written to the plurality of nodes, the detection unit detects a node in which the path information is updated. The detection unit is configured to monitor the path by writing setting information to the plurality of nodes, periodically reading the path information from the plurality of nodes, or notifying from the node in which the path information is updated. The verification apparatus according to claim 1, wherein a node whose information is updated is detected. The path information stores a communication bandwidth to be secured for each output destination of a packet,
The extraction unit extracts a communication band of the communication path together with the communication path,
The verification device according to claim 1, wherein the verification unit further verifies whether the extracted communication band is allocated to the extracted communication path of the network. Among the plurality of nodes constituting the network, a node whose route information indicating the output destination of the input packet is updated is detected,
Extracting a communication path through the detected node from the path information before and after updating the plurality of nodes;
A verification method characterized in that a computer executes a process of verifying the reachability of a test packet that has been sent to an extracted communication path.

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