JP2011101140A - Network emulator device, method of controlling the same, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a network emulator device excellent in extensibility. <P>SOLUTION: An interface module 22 includes virtual nodes 27-1 to 27-N, and a traffic generator 24 transmits information about traffic virtually flowing through the virtual nodes 27-1 to 27-N through the virtual nodes 27-1 to 27-N to a network controller 13 in predetermined timing. The virtual nodes 27-1 to 27-N receive the request of path change transmitted from the network controller 13 and supply it to a resource simulator 23. The resource simulator 23 performs processing to the request of the path change, and transmits information indicating a processing result for the request through the virtual nodes 27-1 to 27-N to the network controller 13. This invention is applicable to a network emulator which tests the network controller, for instance. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a network emulator device, a control method for a network emulator device, and a program, and more particularly to a network emulator device with excellent extensibility, a control method for a network emulator device, and a program.

  Conventionally, in a network configured by connecting a plurality of routers, a network controller predicts traffic demand between the routers and sets a path between the routers so as to obtain an optimum communication environment.

  By the way, in recent years, various types of applications have appeared, and network resources are occupied by applications that require high-capacity and high-quality communication such as high-definition television, video streaming, and high-speed data communication. As a result, it has become difficult for the network controller to predict traffic demand.

  Various services need to be provided through the network, and the network controller needs to control the network so that the network can be used dynamically and efficiently in accordance with customer requirements.

  For example, the network control device disclosed in Non-Patent Document 1 collects topology information and traffic information, and calculates the path route of the path based on these information and an optimal network control policy or algorithm, and Release. Non-patent documents 2 to 4 disclose an optimal network control policy or algorithm.

  Further, when developing such a network control device, a network configured by connecting a plurality of routers according to the network scale is used, and the network control device is configured according to the network configuration and traffic. The behavior is monitored. Various settings are made to the network control device so as to realize an optimum communication environment.

  By the way, when carrying out a test for operating a network control device, it is necessary to connect an actual router to form a large-scale network, which requires a great deal of cost. In addition, in order to develop a network control device that can normally control traffic fluctuations that cannot be expected from the current communication environment, it is necessary to reflect such unpredictable traffic in the network. However, it is difficult to generate such traffic fluctuations in a network configured by connecting real routers.

  Therefore, the applicants of the present application have proposed a network emulator used in a test for operating a network control device in Non-Patent Document 5.

K. Shiomoto, I. Inoue, and E. Oki, ‘‘ Network virtualization in highspeedhuge-bandwidth optical circuit switching network, ’’ High-Speed Networks 2008 (HSN 2008), IEEE INFOCOM 2008, Apr. 2008. Y. Koizumi, T. Miyamura, S. Arakawa, E. Oki, K. Shiomoto, and M. Murata, '' Stability of virtual network topology control for overlay routing services, '' Journal of Optical Networking, vol. 7, no 7, pp.704-719, Jul. 2008. K. Shiomoto, E. Oki, W. Imajuku, S. Okamoto, and N. Yamanaka, `` Distributed Virtual Network Topology Control Mechanism in GMPLS-Based Multi-Region Networks, '' IEEE Journal on Selected Areas in Communications, vol. 21, no. 8, pp. 1254-1262, Oct. 2003. E. Oki, K. Shiomoto, D. Shimazaki, N. Yamanaka, W. Imajuku, and Y. Takigawa, '' Dynamic Multilayer Routing Schemes in GMPLS-based IP + Optical Networks, '' IEEE Commun. Mag., Pp. 108-114, vol. 43, no.1, Jan. 2005. Eiji Oki, Takashi Miyamura, Hiroshi Shiomoto, “Network Emulator Architecture for Network Virtualization on Optical Infrastructure Networks” Proceedings of the IEICE General Conference, vol. 2009, B-12-8, Communication , March 2009.

  By the way, when testing a network control apparatus using a network emulator, it is necessary to change the scale of the network simulated by the network emulator according to the network scale to be controlled by the network control apparatus. However, the above-described network emulator does not disclose the specific configuration, and has excellent extensibility so that the network scale simulated by the network emulator can be easily changed according to the network scale. A network emulator is needed.

  The present invention has been made in view of such a situation, and is intended to provide a network emulator having excellent extensibility.

  A network emulator device according to one aspect of the present invention is a network emulator device connected to a network controller that controls a network configured by a plurality of nodes, and is configured virtually corresponding to each of the plurality of nodes. A plurality of virtual nodes are provided, interface means for communicating with the network controller, and processing corresponding to a request for changing a path that communicates with each of the plurality of virtual nodes and virtually connects the plurality of virtual nodes. Path processing means that performs communication with each of the plurality of virtual nodes, and traffic generation means that virtually generates traffic flowing between the plurality of virtual nodes, the traffic generation means at a predetermined timing, Information about traffic that flows virtually between the virtual nodes To the virtual node, the virtual node transmits information on the traffic supplied from the traffic generation means to the network controller, and receives the path change request transmitted from the network controller. The path change request is supplied to the path processing means, and the path processing means performs processing for the path change request, and supplies information indicating a processing result for the request to the plurality of virtual nodes. The virtual node transmits information indicating the processing result supplied from the traffic generation means to the network controller.

  A control method or program according to one aspect of the present invention executes a method for controlling a network emulator device connected to a network controller that controls a network configured by a plurality of nodes, or a computer that executes processing for controlling the network emulator device. The network emulator device includes a plurality of virtual nodes configured virtually corresponding to each of the plurality of nodes, interface means for communicating with the network controller, and a plurality of the virtual nodes. A path processing unit that communicates with each of the nodes and performs processing in response to a request for changing a path that virtually connects the plurality of virtual nodes; and communicates with each of the plurality of virtual nodes and between the plurality of virtual nodes Virtually generate traffic flowing through Traffic generation means for supplying the virtual node with information on traffic that virtually flows between the virtual nodes at a predetermined timing, and the virtual node supplies the traffic from the traffic generation means. Information regarding the traffic to be transmitted to the network controller, receiving the path change request transmitted from the network controller, supplying the path change request to the path processing means, and the path processing Means for processing the path change request, supplying information indicating a processing result for the request to the plurality of virtual nodes, and the virtual node indicating the processing result supplied from the traffic generation means; Transmitting information to the network controller.

  In one aspect of the present invention, a network emulator device includes a plurality of virtual nodes configured virtually corresponding to each of the plurality of nodes, an interface unit that communicates with the network controller, and each of the plurality of virtual nodes And a path processing means for performing processing in response to a request for changing a path for virtually connecting a plurality of virtual nodes, and communicating with each of the plurality of virtual nodes to virtualize traffic flowing between the plurality of virtual nodes. Traffic generating means for generating automatically. Then, at a predetermined timing, information related to traffic virtually flowing between the virtual nodes is transmitted to the network controller via the virtual nodes, and a path change request transmitted from the network controller is transmitted to the plurality of virtual nodes. Supplied through. Then, a process for a path change request is performed, and information indicating a processing result for the request is transmitted to the network controller via a plurality of virtual nodes.

  According to one aspect of the present invention, it is possible to provide a network emulator device with excellent expandability.

It is a figure which shows the network actually constructed | assembled and the network simulated by an emulator. It is a block diagram which shows the structural example of 1st Embodiment of the emulator to which this invention is applied. It is a flowchart explaining the process which sets a path | pass. It is a flowchart explaining the process which cancels | releases a path | pass. It is a flowchart explaining the process performed in a network emulator. It is a figure which shows the example of mounting of a network emulator. It is a figure which shows the other example of mounting of a network emulator. It is a block diagram which shows the structural example of 2nd Embodiment of a network emulator. It is a block diagram which shows the structural example of 3rd Embodiment of a network emulator.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings.

  First, with reference to FIG. 1, a description will be given of a network controller test by a network actually constructed and a network controller test by a network virtually constructed by an emulator.

  As shown in FIG. 1A, the network 11 is configured by connecting nodes 12-1 to 12-4, and setting and canceling a path between the nodes 12-1 to 12-4 is performed by the network controller 13. Controlled by

  The nodes 12-1 to 12-4 are actual routers, which generate traffic by actually transmitting and receiving data between the nodes 12-1 to 12-4. The nodes 12-1 to 12-4 Traffic information indicating the actual traffic volume is transmitted to the network controller 13 and topology information indicating the connection form of the network 11 is transmitted. Then, what kind of control the network controller 13 performs according to traffic information and topology information is monitored.

  In contrast, the network emulator 21 of FIG. 1B uses virtual nodes 12-1 ′ to 12-4 ′ instead of the nodes 12-1 to 12-4 configuring the network 11 in order to test the network controller 13. Provide a test environment.

  Data is not actually transmitted / received between the virtual nodes 12-1 ′ to 12-4 ′ simulated by the network emulator 21, but the virtual nodes 12-1 ′ to 12-4 ′ are in accordance with the test environment. The traffic information generated in this manner is transmitted to the network controller 13 and the topology information of the network virtually constituted by the virtual nodes 12-1 ′ to 12-4 ′ is transmitted to monitor the behavior of the network controller 13. The In this way, since the network emulator 21 does not actually transmit or receive data, it can transmit traffic information that cannot actually occur and cannot be assumed from the current communication environment. It is monitored what kind of control the network controller 13 performs for traffic fluctuations that are beyond the prediction range (which is difficult to predict).

  First, the required conditions are presented to the network emulator 21 that virtually constructs such a network.

  As a first requirement, the network emulator 21 needs to have an interface function. For example, the network emulator 21 needs to simulate an interface of a router connected to an optical IP (Internet Protocol) cooperation server platform. As the interface, it is necessary to support Telnet (Telecommunication network) and SNMP (Simple Network Management Protocol). Telnet supports path setup and release commands, and SNMP commands support the acquisition of traffic information.

  As a second requirement, the network emulator 21 needs to have a resource simulation function. For example, the network emulator 21 needs to simulate the behavior of the network by simulation. For example, network management is based on GMPLS (Generalized Multi-Protocol Label Switching) for optical networks and multi-protocol label switching (MPLS) for IP networks. No. 21 needs to simulate the behavior of GMPLS / MPLS. Information for managing resources such as topology information is defined by OSPF-TE (Open Shortest Path First-Traffic Engineering). For example, the network emulator 21 reduces the remaining bandwidth of the link used by the set path when the path is set, and reduces the remaining bandwidth of the link used by the path when the path is released. increase.

  As a third requirement, the network emulator 21 needs to have a traffic information generation function. The network emulator 21 needs to support a function of generating traffic information by simulating traffic generated on the network, reflecting future traffic fluctuations that are difficult to predict.

  As a fourth requirement, the network emulator 21 needs to have expandability and flexibility. The network emulator 21 needs to have extensibility that does not strongly depend on hardware limitations even when the network scale increases. In addition, the network emulator 21 needs to be able to change the configuration flexibly in response to a topology change, that is, addition or deletion of a node or a link.

  The network emulator 21 is configured to satisfy the first to fourth requirements.

  FIG. 2 is a block diagram showing a configuration example of the first embodiment of the network emulator.

  2, the network emulator 21 includes an interface module 22, a resource simulator 23, a traffic generator 24, a TE (Traffic Engineering) database 25, and a traffic database 26. The interface module 22 includes a plurality of submodules including N virtual nodes 27-1 to 27-N and one virtual node R28. The interface module 22 corresponds to the interface means of the present invention, the resource simulator 23 corresponds to the path processing means of the present invention, the traffic generator 24 corresponds to the traffic generation means of the present invention, and the virtual nodes 27-1 to 27 -N corresponds to the virtual node of the present invention.

  In the network emulator 21, a network is virtually configured by virtual nodes 27-1 to 27 -N simulated in the interface module 22, and the network controller 13 controls the virtually configured network.

  Further, the interface module 22 can flexibly change the number of virtual nodes 27-1 to 27 -N in accordance with the addition or deletion of a router constituting the network simulated by the network emulator 21. That is, a number of virtual nodes corresponding to the scale of the network simulated by the network emulator 21 are prepared in the interface module 22.

  The virtual nodes 27-1 to 27 -N virtually realize the function of an edge router (router having an interface for communicating with the network controller 13) connected to the network controlled by the network controller 13. Further, the virtual nodes 27-1 to 27-N communicate with the network controller 13 by CLI / SNTP (Command Line Interface / Simple Network Management Protocol). In addition, when it is not necessary to distinguish each of the virtual nodes 27-1 to 27-N, hereinafter, they are simply referred to as virtual nodes 27 as appropriate.

  For example, a path setup request for requesting path setting and a path release request for requesting path cancellation are transmitted from the network controller 13 to the virtual nodes 27-1 to 27 -N. On the other hand, traffic information corresponding to traffic virtually generated between the virtual nodes 27-1 to 27 -N is transmitted from the virtual nodes 27-1 to 27 -N to the network controller 13 to the network controller 13. Is done.

  The virtual node R28 communicates with the network controller 13 by OSPF (Open Shortest Path First), and realizes a function as an interface for exchanging topology information and resource information with the network controller 13.

  When the network controller 13 requests the virtual nodes 27-1 to 27-N to set or release a path, the resource simulator 23 refers to the resource information stored in the TE database 25 and performs processing for the request. Do. Then, the resource simulator 23 updates the topology information and resource information stored in the TE database 25 according to the result of the processing, and updates the new topology information and resource information to the virtual nodes 27-1 to 27-N or the virtual node. To R28.

  The traffic generator 24 virtually generates traffic flowing in the paths currently set in the virtual nodes 27-1 to 27 -N with reference to a traffic generation model (detailed later) stored in the traffic database 26. Traffic information indicating the traffic volume is supplied to the virtual nodes 27-1 to 27-N. As a result, traffic fluctuations in a network virtually constituted by the virtual nodes 27-1 to 27-N are simulated.

  The TE database 25 indicates topology information indicating the connection form of the virtual nodes 27-1 to 27 -N, and resources such as used bandwidth and usable bandwidth of paths set in the virtual nodes 27-1 to 27 -N. Manage resource information. The traffic database 26 manages a traffic generation model that is a model for virtually generating traffic in the virtual nodes 27-1 to 27 -N in order to test the network controller 13. The traffic generation model describes the timing at which traffic is generated, traffic information indicating the amount of traffic generated, and the virtual node 27 that is the target of the traffic generation. It should be noted that the traffic generation model of the traffic database 26 includes traffic information that causes traffic fluctuations that cannot be assumed at present.

  Here, in the network emulator 21, communication between the virtual nodes 27-1 to 27 -N, the resource simulator 23, and the traffic generator 24 using the TCP / IP (Transmission Control Protocol / Internet Protocol), the virtual node Communication between R28, the resource simulator 23, and the traffic generator 24, and communication between the resource simulator 23 and the traffic generator 24 are performed.

  For example, in communication between the virtual nodes 27-1 to 27-N and the resource simulator 23, a path setup request or path release request transmitted from the network controller 13, topology information updated in response to the request, and the like. Are sent and received using TCP / IP. In the communication between the virtual nodes 27-1 to 27-N and the traffic generator 24, traffic information is transmitted from the traffic generator 24 to the virtual nodes 27-1 to 27-N using TCP / IP. The

  Further, for example, in communication between the virtual node R28 and the resource simulator 23, topology information and resource information updated according to the behavior of the network from the resource simulator 23 to the virtual node R28 are transmitted using TCP / IP. Sent. In communication between the resource simulator 23 and the traffic generator 24, the current topology information is transmitted from the resource simulator 23 to the traffic generator 24 using TCP / IP.

  As described above, communication between the virtual nodes 27-1 to 27 -N, the resource simulator 23, and the traffic generator 24 inside the network emulator 21, that is, blocks whose connections are indicated by broken-line arrows in FIG. 2. Communication between them is performed by TCP / IP.

  In this way, the network emulator 21 is designed to perform communication using TCP / IP, so that in the network emulator 21, the virtual nodes 27-1 to 27 -N, the virtual node R 28, the resource simulator 23, and the traffic generator 24 can be mounted on different computers. In addition, a network configured virtually in the network emulator 21 operates in a distributed manner. That is, the network emulator 21 has expandability with respect to the network scale.

  Further, in the network emulator 21 configured in this way, the virtual nodes 27-1 to 27-N behave in the same manner as the actual nodes (for example, the node 12 in FIG. 1), that is, from the network controller 13. Since the interface of the seen network is configured in the same manner as the actual network, the network controller 13 can perform the same processing as controlling the node of the actual machine. Therefore, the network controller 13 can be tested by the network emulator 21 without actually constructing the network.

  As described above, the network emulator 21 is configured. When the network controller 13 is connected to the network simulated by the network emulator 21 and the network controller 13 is instructed to control the network, the network controller 13 Based on the traffic information and the topology information, the setting or cancellation of the path between the virtual nodes 27-1 to 27-N is controlled.

  Next, FIG. 3 is a flowchart for explaining processing for setting a path in a network virtually constituted by the virtual nodes 27-1 to 27-N.

  In step S11, the network controller 13 communicates using the CLI on Telnet, logs in to the virtual node 27 that sets the path among the virtual nodes 27-1 to 27-N, and the process proceeds to step S12. move on.

  In step S12, the network controller 13 transmits a path setup request for requesting path setting to the virtual node 27 logged in in step S11. The path setup request includes information indicating physical port address, IP address, necessary bandwidth, necessary route, and switch type attribute. The virtual node 27 stores the information included in the path setup request and proceeds to step S13.

  In step S13, the virtual node 27 that has received the path setup request transmitted from the network controller 13 in step S12 confirms the accuracy of the information included in the path setup request and activates it. Then, the virtual node 27 supplies the information included in the path setup request to the resource simulator 23, and the process proceeds to step S14.

  In step S <b> 14, the resource simulator 23 determines whether the path requested from the network controller 13 can be set. For example, the resource simulator 23 refers to the resource information stored in the TE database 25, and can set a path if the bandwidth of the path requested to be set is free of the requested bandwidth. If there is no available bandwidth, it is determined that a path cannot be set.

  If the resource simulator 23 determines in step S14 that a path can be set, the process proceeds to step S15. The resource simulator 23 updates the resource information and topology information stored in the TE database 25 based on the newly set path, and indicates that a new path has been set for the virtually configured network. 27-1 to 27-N. Further, the resource simulator 23 notifies the updated resource information and topology information to the virtual node R28.

  On the other hand, when the resource simulator 23 determines in step S14 that the path cannot be set, the process proceeds to step S16, and the resource simulator 23 transmits the path setup request information in step S13 to the virtual node 27 that has transmitted the information. Notify that the path cannot be set.

  After the process of step S15 or S16, the process proceeds to step S17, the result for the path setup request is transmitted to the network controller 13, and the process ends. For example, when a new path is set in step S15, the virtual nodes 27-1 to 27-N transmit to the network controller 13 that the new path has been set, and the virtual node R28 The updated resource information and topology information are transmitted to the network controller 13. On the other hand, when it is notified in step S16 that the path cannot be set, the virtual node 27 that has received the notification transmits to the network controller 13 that the path has not been set.

  Next, FIG. 4 is a flowchart for explaining processing for canceling a path set in a network virtually constituted by the virtual nodes 27-1 to 27-N.

  In step S21, the network controller 13 communicates using the CLI on Telnet, and logs in to the virtual node 27 that releases the path among the virtual nodes 27-1 to 27-N, and the processing proceeds to step S22. move on.

  In step S22, the network controller 13 transmits a path release request for requesting cancellation of the path to the virtual node 27 logged in in step S21. The path release request includes information for confirming the path based on the local and remote IP addresses. After the process of step S22, the process proceeds to step S23.

  In step S23, the virtual node 27 that has received the path release request transmitted from the network controller 13 in step S22 confirms the accuracy of the information included in the path release request and activates it. Then, the virtual node 27 supplies the information included in the path release request to the resource simulator 23, and the process proceeds to step S24.

  In step S24, the resource simulator 23 updates the resource information and topology information stored in the TE database 25 so as to release the path requested by the path release request, and the process proceeds to step S25.

  In step S25, the resource simulator 23 notifies the virtual nodes 27-1 to 27-N that the path set in the virtually configured network has been released. Further, the resource simulator 23 notifies the updated resource information and topology information to the virtual node R28.

  In step S26, the virtual nodes 27-1 to 27-N transmit to the network controller 13 that the path has been released, and the virtual node R28 transmits the updated resource information and topology information to the network controller 13. Then, the process ends.

  As described above, path setting and cancellation for a network virtually constituted by the virtual nodes 27-1 to 27-N are performed.

  Next, FIG. 5 is a flowchart for explaining processing executed in the network emulator 21.

  First, when the network emulator 21 is mounted on a plurality of computers, the user determines the number of computers necessary for the mounting, prepares a virtual machine for each computer, and connects the computers with a communication cable. An example of mounting the network emulator 21 on a plurality of computers will be described later with reference to FIG.

  Then, when the user assigns the resource simulator 23, the traffic generator 24, the virtual nodes 27-1 to 27-N, and the virtual node R28 to each computer, the process is started. Initial settings are made.

  For example, the resource simulator 23 sets the network configuration (virtual nodes connected to the network, links between them) by the virtual nodes 27-1 to 27-N when starting the test of the network controller 13, Topology information and resource information based on the configuration are stored in the TE database 25. The traffic generator 24 sets (selects) a traffic generation model used in the test and stores it in the traffic database 26.

  After step S31, in step S32, the TCP / IP connection is established between the resource simulator 23, the virtual nodes 27-1 to 27-N and the virtual node R28, and the traffic generator 24 and the virtual node 27- A connection by TCP / IP is established between 1 to 27-N and the virtual node R28, a connection by TCP / IP is established between the resource simulator 23 and the traffic generator 24, and the process proceeds to step S33.

  In step S <b> 33, the network emulator 21 is activated, and the virtual nodes 27-1 to 27 -N and the virtual node R <b> 28 start communication with the network controller 13. For example, the virtual nodes 27-1 to 27 -N start communication with the network controller 13 using CLI / SNTP, and the virtual node R 28 starts communication with the network controller 13 using OSPF. Thereby, the test of the network controller 13 is started.

  After the process of step S33, the process proceeds to step S34, and the traffic generator 24 determines whether or not virtual traffic is generated in a network virtually constituted by the virtual nodes 27-1 to 27-N. For example, the traffic generator 24 refers to the traffic generation model, determines that the traffic is generated if it is a timing for generating the traffic, and determines that the traffic is not generated if it is not the timing for generating the traffic.

  If it is determined in step S34 that the traffic generator 24 generates traffic, the process proceeds to step S35, and the traffic generator 24 refers to the traffic generation model and uses the traffic information associated with the current timing as traffic. Is supplied to the virtual node 27 that is the target of the occurrence of. The traffic generator 24 generates traffic between the virtual nodes 27 for which paths are set with the current topology information. The virtual node 27 supplied with the traffic information transmits the traffic information to the network controller 13 by CLI / SNTP.

  After step S35, or when it is determined in step S34 that the traffic generator 24 does not generate traffic, the process proceeds to step S36, and the virtual nodes 27-1 to 27-N receive requests from the network controller 13. It is determined whether it has come.

  In step S36, when the virtual nodes 27-1 to 27-N determine that the request is not transmitted from the network controller 13, the process returns to step S34, and the same process is performed thereafter. On the other hand, if any of the virtual nodes 27 determines in step S36 that a request has been transmitted from the network controller 13, the process proceeds to step S37.

  In step S37, the virtual node 27 having determined that the request has been transmitted from the network controller 13 receives the request transmitted from the network controller 13, supplies the request to the resource simulator 23, and the process proceeds to step S38. move on.

  In step S38, the resource simulator 23 determines the content of the request from the network controller 13.

  In step S38, when the resource simulator 23 determines that the content of the request from the network controller 13 is a path setup request, the process proceeds to step S39, and the resource simulator 23 performs a process of setting a path. That is, the resource simulator 23 determines whether or not a path can be set by referring to the resource information stored in the TE database 25 as described in steps S14 to S16 in FIG. 3, and based on the determination result. Process.

  On the other hand, when the resource simulator 23 determines in step S38 that the content of the request from the network controller 13 is a path release request, the process proceeds to step S40, and the resource simulator 23 performs a process for releasing the path. . That is, the resource simulator 23 performs processing for releasing the path by updating the resource information stored in the TE database 25 as described in steps S24 and S25 of FIG.

  After the process of step S39 or S40, the process proceeds to step S41, and the virtual nodes 27-1 to 27-N transmit the process result of step S39 or S40 to the network controller 13. For example, as described in step S17 in FIG. 3, a new path has been set or a path has not been set, or the path is released as described in step S26 in FIG. The network controller 13 is notified as a processing result. After the process of step S41, the process returns to step S34, and the same process is performed thereafter.

  As described above, the network emulator 21 generates traffic in the virtually configured network, and processing (path setting or cancellation) corresponding to the request transmitted from the network controller 13 is performed according to the traffic. For example, it is possible to test what control the network controller 13 performs for the occurrence of traffic that is difficult to predict. Further, since communication with the network controller 13 is performed via the virtual nodes 27-1 to 27 -N and the virtual node R 28 configured in the interface module 22, the network controller 13 is processed similarly to the actual network. Can be performed.

  Next, an example in which the network emulator 21 is mounted on a computer will be described.

  For example, in the implementation of a virtual node having a CLI / SNMP / OSPF interface, it is possible to implement one virtual node in association with one computer, but such a one-to-one correspondence configuration is efficient. Since it is bad, VM (Virtual Machine) technology is used. In the VM technology, a plurality of virtual nodes (machines) can be mounted on one computer, and the plurality of nodes can be operated independently.

  The number of virtual nodes that can be mounted on one computer is determined by the CPU power and memory capacity of the computer. Here, assuming that the number of virtual nodes that can be mounted on one computer is M, and the number of virtual nodes 27 having a CLI / SNMP interface with the network controller 13 is N, N virtual nodes are provided. In order to emulate the network constituted by the nodes 27, N / M computers are required.

  Further, the virtual node R28, the resource simulator 23, and the traffic generator 24 having an OSPF interface are mounted on one computer because the calculation load does not greatly depend on the network scale.

  Accordingly, the network emulator 21 can be implemented by (N / M + 1) computers.

  Next, FIG. 6 is a diagram showing an implementation example of the network emulator 21 shown in FIG. In the implementation example of FIG. 6, a network is virtually configured by 40 virtual nodes 27-1 to 27-40 (N = 40).

  The system shown in FIG. 6 is configured by connecting four computers 32-1 to 32-4 via a communication cable 31. The computers 32-1 to 32-4 perform communication corresponding to an interface conforming to an Ethernet standard such as 100BASE-TX having a transfer rate of 100 Mbps via the communication cable 31.

  The computers 32-1 to 32-4 have a processing capability (M = 20) that can implement 20 virtual nodes 27, and the virtual nodes 27-1 to 27-20 are mounted on the computer 32-1. The virtual nodes 27-21 to 27-40 are mounted on the computer 32-2.

  A virtual node R28, a resource simulator 23, and a traffic generator 24 are mounted on the computer 32-3, and the storage unit is used as the TE database 25 and the traffic database 26. The network controller 13 is mounted on the computer 32-4.

  As shown in FIG. 6, virtual nodes 27-1 to 27-40 and virtual node R28 provided in the interface module 22 are distributed and mounted on three computers 32-1 to 32-3. This is realized by three computers 32-1 to 32-3. As described above, each block constituting the network emulator 21 is designed to perform communication by TCP / IP. For example, when the number of virtual nodes 27 is to be increased, a new computer is connected to the communication cable. It is only necessary to set up the required number of virtual nodes 27 by connecting to the network 31, and the network scale to be simulated can be easily (flexibly) changed. That is, since communication is performed using the general-purpose TCP / IP inside the network emulator 21, excellent expandability can be realized. Note that the network emulator 21 can have the same expandability by adopting general-purpose communication other than TCP / IP.

  Further, for example, the computers 32-1 to 32-4 may be configured to be connected via the Internet, and even if the computers 32-1 to 32-4 are installed at separate locations, a network emulator may be used. The function as 21 can be realized.

  In addition to mounting the network emulator 21 on a plurality of computers, the network emulator 21 may be mounted on a single computer by using a high-performance computer or reducing the number of virtual nodes 27.

  That is, FIG. 7 is a diagram showing another implementation example of the network emulator 21 shown in FIG. In the implementation example of FIG. 7, a network is virtually configured by ten virtual nodes 27-1 to 27-10 (N = 10).

  As shown in FIG. 7, a computer 33-1 and a computer 33-2 are connected via a communication cable 31, the network emulator 21 is mounted on the computer 33-1, and the network controller 13 is connected to the computer 33-2. Has been implemented.

  Similar to the computer 32 in FIG. 6, the computer 33 has a processing capability (M = 20) that can be mounted on the 20 virtual nodes 27, and the number of virtual nodes that can be mounted on the computer 32 ( Since the number (N) of virtual nodes 27 that virtually configure the network is sufficiently smaller than M), the virtual nodes 27-1 to 27-10, virtual node R28, resource simulator 23, And a traffic generator 24 can be implemented.

  Thus, even when the network emulator 21 is mounted on one computer 33-1, each block constituting the network emulator 21 is designed to perform communication by TCP / IP. For example, after the network controller 13 is tested on a network of a scale that can be mounted on one computer 33-1, it can be operated so as to shift to a test on a larger network.

  Next, FIG. 8 is a block diagram showing a configuration example of the second embodiment of the network emulator.

  FIG. 8 shows virtual nodes 27-1 to 27-N, a virtual node R28, a resource simulator 23, and a traffic generator 24 among the blocks constituting the network emulator 21 of FIG.

  As shown in FIG. 8, the virtual nodes 27-1 to 27-N include virtual node processing units 51-1 to 51-N, buffers 52-1 to 52-N and 53-1 to 53-N, and a timer 54-. 1 to 54-N and delay processing units 55-1 to 55-N, respectively. The delay processing units 55-1 to 55-N correspond to the delay unit of the present invention.

  The virtual node R28 includes a virtual node processing unit 61, buffers 62 and 63, a timer 64, and a delay processing unit 65. The resource simulator 23 includes a resource simulator processing unit 71 and buffers 72-1 to 72-N and 73, and the traffic generator 24 includes a traffic generator processing unit 81 and buffers 82-1 to 82-N. And 83.

  In the network emulator 21 configured as described above, data transmitted and received between each block is temporarily accumulated in a buffer, and the accumulated data is sequentially processed.

  For example, in the resource simulator 23, the resource simulator processing unit 71 processes the processing requests from the virtual nodes 27-1 to 27-N and the virtual node R28 one by one. Therefore, when a plurality of processing requests arrive, the resource simulator 23 temporarily stores the processing requests in the buffers 72-1 to 72-N and 73, and the resource simulator processing unit 71 performs sequential processing. For example, the resource simulator processing unit 71 can perform processing by selecting processing requests in the order of arrival, or can perform processing by a round robin method in which each processing is divided into predetermined time intervals and executed in order.

  In the resource simulator 23, when a plurality of processing requests arrive in a short time, the queues of the buffers 72-1 to 72-N and 73 are prevented so that the buffers 72-1 to 72-N and 73 do not overflow. When the length exceeds a predetermined threshold, a suppression signal is sent to the virtual nodes 27-1 to 27-N and the virtual node R28 so that processing requests do not reach from the virtual nodes 27-1 to 27-N and the virtual node R28. Perform flow control like sending.

  The traffic generator 24 also performs processing using the buffers 82-1 to 82-N and 83, similarly to the resource simulator 23.

  Incidentally, in an actual network, a predetermined delay time is required until a response to the request is received after a request is transmitted from the network controller 13 to each node according to the route. However, in the experiment of the network controller 13 using the network emulator 21, the path between the network controller 13 and the network emulator 21 is shortened, and unlike the behavior in the actual network, the process from the transmission of the request to the reception of the response. Delay time is shortened.

  Therefore, in the network emulator 21, the delay time can be emulated by the timers 54-1 to 54-N, the delay processing units 55-1 to 55-N, the timer 64, and the delay processing unit 65.

  For example, when the virtual node 27-1 is requested to send a response from the resource simulator 23 to the network controller 13, the virtual node processing unit 51-1 temporarily sends the response to the delay processing unit 55-1. The timer 54-1 is made to store the time. When the preset delay time is reached, the timer 54-1 notifies the delay processing unit 55-1 that the delay time has elapsed, and in response to this, the delay processing unit 55-1 sends a response to the network controller. 13 to send.

  As described above, the network emulator 21 can behave in the same manner as the actual network by emulating the delay time caused by the data passing through the actual network path.

  The setting of the degree of delay generated in the delay processing unit 65, that is, the setting of the virtual distance from the virtual node 27 to the network controller 13 is determined by a predetermined delay model, for example, step S31 in FIG. In the initial setting, virtual nodes 27-1 to 27-N are set.

  Next, FIG. 9 is a block diagram showing a configuration example of the third embodiment of the network emulator.

  The network emulator 91 of FIG. 9 includes an emulator processing unit 92, a network configuration setting input unit 93, and a failure generation unit 94. The failure generation unit 94 corresponds to the failure generation means of the present invention.

  The emulator processing unit 92 is configured in the same manner as the network emulator 21 of FIG. 2, and the virtual nodes 27-1 to 27 -N that virtually configure the network in the network emulator 91 are controlled by the network controller 13.

  The network configuration setting input unit 93 is connected to an input device (not shown) such as a keyboard and a mouse, and the network configuration in the emulator processing unit 92 according to a signal input from the input device according to a user operation. Set the parameters. The parameters set by the network configuration setting input unit 93 include the contents of Opaque LSA (LINK State Advertisements) advertised by OSPF-TE (for example, router IP address, interface IP address, link bandwidth). .

  For example, when network simulation is started by the emulator processing unit 92, the user inputs parameters as network initial settings via the network configuration setting input unit 93. Thereafter, network emulation is performed by the resource simulator 23 and the traffic generator 24 in accordance with the control by the network controller 13, and the experiment of the network controller 13 is started.

  In the network emulator 91, the failure generation unit 94 automatically generates a failure in the link or node at a predetermined timing according to a predetermined failure generation model (pre-programmed scenario), and the network configuration setting input unit 93 is By setting in the emulator processing unit 92 via the network, the network parameters of the emulator processing unit 92 can be changed.

  For example, when information indicating that a failure has occurred in a predetermined virtual node 27 is output from the failure generation unit 94, the interface module 22 performs a process of stopping the function of the virtual node 27 specified by the information. Further, for example, when information indicating that a failure has occurred in a predetermined link is supplied by the failure generation unit 94, the resource simulator 23 performs a process of releasing the path connected by the link specified by the information. Do.

  As described above, the network emulator 91 can test the behavior of the network controller 13 when a failure occurs in the link between the virtual nodes 27-1 to 27 -N or the virtual nodes 27-1 to 27 -N. . Note that the setting for causing a pseudo failure of a link or node may be input to the network emulator 91 by a user operating an input device (not shown).

  The embodiment of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

  11 network, 12-1 to 12-4 node, 12-1 ′ to 12-4 ′ virtual node 13 network controller, 21 network emulator, 22 interface module, 23 resource simulator, 24 traffic generator, 25 TE database, 26 traffic database 27 virtual nodes, 28 virtual nodes R, 31 communication cables, 32 computers, 33 computers, 51 virtual node processing units, 52 and 53 buffers, 54 timers, 55 delay processing units, 61 virtual node processing units, 62 and 63 buffers, 64 timers, 65 delay processing units, 71 resource simulator processing units, 72 and 73 buffers, 81 Traffic generator processing unit, 82 and 83 buffer, 91 network emulator, 92 emulator processing unit, 93 network configuration setting input unit, 94 fault generation unit

Claims (8)

In a network emulator device connected to a network controller that controls a network composed of a plurality of nodes,
A plurality of virtual nodes configured virtually corresponding to each of the plurality of nodes, interface means for communicating with the network controller;
Path processing means that communicates with each of the plurality of virtual nodes and performs processing in response to a request for changing a path that virtually connects the plurality of virtual nodes;
Traffic generating means for communicating with each of the plurality of virtual nodes and virtually generating traffic flowing between the plurality of virtual nodes;
The traffic generation means supplies the virtual node with information related to traffic that virtually flows between the virtual nodes at a predetermined timing,
The virtual node transmits information on the traffic supplied from the traffic generation means to the network controller, receives the path change request transmitted from the network controller, and sends the path change request. Supplying to the path processing means,
The path processing means performs processing for the path change request, supplies information indicating a processing result for the request to the plurality of virtual nodes,
The network emulator device, wherein the virtual node transmits information indicating the processing result supplied from the traffic generation unit to the network controller. When the path processing unit is requested by the network controller to set a path between the virtual nodes via the virtual node, the bandwidth used and the usage of the path currently set in the plurality of virtual nodes The network emulator device according to claim 1, wherein processing for the request is performed based on resource information related to a resource in a possible bandwidth. For communication between the plurality of virtual nodes provided in the interface means and the path processing means, and between the plurality of virtual nodes provided in the interface means and the traffic generation means, TCP / The network emulator device according to claim 1, wherein IP (Transmission Control Protocol / Internet Protocol) is used. The network emulator device according to claim 1, wherein the interface unit, the path processing unit, and the traffic generation unit are mounted on a plurality of computers. The network emulator apparatus according to claim 1, wherein each of the plurality of virtual nodes provided in the interface unit includes a delay unit that delays data to be transmitted to the network controller. A failure generation means for virtually generating a failure in the virtual node or a link between the virtual nodes at a timing according to a predetermined failure occurrence model, and outputting information indicating that the failure has occurred;
The interface means stops the function of the virtual node specified by the information indicating that the failure has occurred;
The network emulator apparatus according to claim 1, wherein the path processing unit cancels a path between the virtual nodes connected by the link specified by information indicating that the failure has occurred. In a method for controlling a network emulator device connected to a network controller that controls a network constituted by a plurality of nodes,
The network emulator device includes a plurality of virtual nodes configured virtually corresponding to each of the plurality of nodes, interface means for communicating with the network controller, and communicates with each of the plurality of virtual nodes, A path processing means for performing a process in response to a request for changing a path for virtually connecting the plurality of virtual nodes; Traffic generating means for generating
The traffic generation means supplies the virtual node with information related to traffic that virtually flows between the virtual nodes at a predetermined timing,
The virtual node transmits information on the traffic supplied from the traffic generation means to the network controller, receives the path change request transmitted from the network controller, and sends the path change request. Supplying to the path processing means,
The path processing means performs processing for the path change request, and supplies information indicating a processing result for the request to the plurality of virtual nodes;
A method for controlling a network emulator device, comprising: a step in which the virtual node transmits information indicating the processing result supplied from the traffic generation means to the network controller. In a program for causing a computer to execute processing for controlling a network emulator device connected to a network controller that controls a network constituted by a plurality of nodes,
The network emulator device includes a plurality of virtual nodes configured virtually corresponding to each of the plurality of nodes, interface means for communicating with the network controller, and communicates with each of the plurality of virtual nodes, A path processing means for performing a process in response to a request for changing a path for virtually connecting the plurality of virtual nodes; Traffic generating means for generating
The traffic generation means supplies the virtual node with information related to traffic that virtually flows between the virtual nodes at a predetermined timing,
The virtual node transmits information on the traffic supplied from the traffic generation means to the network controller, receives the path change request transmitted from the network controller, and sends the path change request. Supplying to the path processing means,
The path processing means performs processing for the path change request, and supplies information indicating a processing result for the request to the plurality of virtual nodes;
The virtual node includes a step of transmitting information indicating the processing result supplied from the traffic generation means to the network controller.

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