JP2009164706A - Network simulation system, network simulation method, and network simulation program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a network simulation system that realizes highly accurate network connection verification.
In order to transmit predetermined data to an evaluation device from a requesting terminal via a network model simulation apparatus, and to perform evaluation by network connection verification for the evaluation device, the predetermined data is converted into virtual data. And the generation of traffic for the network model, other load data that gives load, and the behavior of these data as frame data executed by the data link layer protocol are managed. A simulation system for verifying network connection of an evaluation device is provided.
[Selection] Figure 2

Description

The present invention relates to a network simulation system, a network simulation method, and a network simulation program for performing network connection verification on an evaluation device, and in particular, predetermined data is sent to an evaluation device from a request terminal via a simulation apparatus that generates a network model. The present invention relates to an apparatus that transmits data by packet communication and evaluates the evaluation device by network connection verification.

  In recent years, function verification of devices such as printers and multifunction peripherals has become increasingly important not only for stand-alone operation verification but also for network connection verification. Differences in the accuracy of network connection verification greatly affect product reliability and contribute to prevention of rework.

  However, when the network configuration is large or complicated, it is difficult to construct a network based on a real machine in order to perform connection verification, which is not realistic in terms of cost.

  Accordingly, in the packet communication method, a desired virtual network model is generated by a discrete event simulation (Discrete Event Simulation) system interposed between a requesting terminal and an evaluation device, and a virtual packet is generated within the virtual network model. In general, connection verification such as detection of an event of network down is performed by distributing a network and applying a load to a specific object in a model.

  For example, conventionally, when a simulation is performed such that packet communication is performed between the first and second communication terminal apparatuses using a predetermined application, each delay of a plurality of measurement packets generated between the first and second nodes Time is measured in advance and stored in the first storage means, and a plurality of packets are generated between the first and second communication terminal devices using the application, and each generated packet is received and received. A network simulation apparatus and method have been proposed in which each packet is stored and held in the second storage means for each delay time stored in the first storage means (see, for example, Patent Literature 1). 1).

According to the simulation apparatus and method, a large-scale and complex virtual network model can be constructed simply, quickly, and at low cost by the simulation apparatus and method.
JP 2001-251302 (Claim 1)

  By the way, in the packet communication method, a plurality of communication protocols are modeled by forming a hierarchical structure. However, in the virtual network model generated by the conventional technique, which communication protocol is necessarily reproduced to perform the simulation. It was not clear. For example, the execution of packet processing by simulation up to the network layer (third layer of the OSI reference model) or the IP layer (third layer of the TCP / IP protocol) is limited to the data link layer (second layer of the OSI reference model). ) Alternatively, if the frame processing at the network interface layer (the first layer of the TCP / IP protocol) is ignored (or discarded), the fine granularity of data handled in the virtual environment becomes coarse, resulting in the above connection verification. There was an inconvenience that the accuracy dropped.

  In addition to the delay and loss of information due to data (packet) traffic (amount of information), various terminals and devices installed on the network, and these terminals cause some troubles in the actual network. Various data processed by devices and devices also have an effect as a cause of trouble. However, in the above prior art, it is difficult to perform simulation of these terminals and devices existing on an actual network or the various data in the virtual network model.

  Therefore, in view of the above problems, the present invention provides a network simulation system and a network simulation for constructing a virtual environment having a large-scale and complicated network configuration in a simple, rapid and low-cost manner and realizing highly accurate network connection verification. It is an object to provide a method and a network simulation program.

  In order to solve the above-described problem, a network simulation system according to the present invention transmits predetermined data to an evaluation device by a packet communication method from a requesting terminal via a simulation device that generates a network model. A network simulation system for performing evaluation by network connection verification, wherein the simulation device is based on configuration data storage means of a network model used for generating the network model, and configuration data selected from the configuration data storage means Network model generating means for generating a network model in a virtual environment, receiving means for receiving the predetermined data from the requesting terminal, and converting the received data into virtual data that can be distributed in the network model. First conversion means, second conversion means for converting the virtual data into data receivable by the evaluation device, transmission means for transmitting the converted data to the evaluation device, and in addition to the virtual data Load data generation means for generating request data for the evaluation device for the purpose of generating a load in the network model, and network interface means for sending and capturing the virtual data and load data to and from the network model And data management means for setting various parameters of the virtual data and load data distributed in the network model and managing the behavior of these data as events, and the network connection verification of the evaluation device from the behavior of the virtual data Evaluation means for performing the virtual data and Loading data, at least, characterized in that it is a frame data performed by the data link layer protocol.

  According to this configuration, the network simulation system according to the present invention implements the predetermined data transmitted from the requesting terminal to the evaluation device and the load data generated by the load data generation means by the data link layer protocol in the network model. Can be distributed as frame data.

For example, in an actual bridge network, in order to prevent a broadcast storm, a loop in the network is automatically detected by STP (Spaninng tree protocol) belonging to the data link layer, and the loop is cut. At this time, a BPDU (bridge protocol data unit) is transmitted as a broadcast frame. Therefore, in order to evaluate the behavior of the BPDU in the network model, the evaluation means may include an evaluation of the behavior of the BPDU.

  The configuration data storage means includes an object management library storing various node data virtually installed in the network model, and a network setting library including at least topology data, routing control algorithm data, and traffic data. do it. Various node data may be routers, switches, servers installed in the network model, evaluation devices installed in the network model in addition to the evaluation devices to be evaluated, or similar devices, etc. Good.

  The accuracy of the evaluation for the evaluation device by the network connection verification is improved by executing a large number of distributed values using the data transmission timing and frequency, the data size, and the like as random variables. Therefore, in order to obtain probability distribution values for these random variables and improve accuracy, the management means may be provided with random number generation means for randomly generating parameters for distributing load data.

  Data processing in the requesting terminal and the evaluation device operates in real time, and data processing in the network model operates in virtual time. For example, event processing on the OS of the virtual server that is not on the communication path installed in the network model is skipped. Therefore, when the actual event processing is skipped in the network model, the simulation apparatus may be provided with a clock synchronization processing means for setting the time required for the event processing as a standby time and adjusting the time.

  The load data generation means generates various data distributed in an actual network in addition to data for generating traffic in the network model, and the data management means processes these data as necessary, The load may be amplified. The data other than the data that generates the traffic is, for example, past actual measurement data, data in which trouble has occurred in the past, prototype data, competitor data, confidential data, and the like.

In order to solve the above-described problem, a network simulation method according to the present invention transmits predetermined data to an evaluation device by a packet communication method from a requesting terminal through a network model generated as a virtual environment by a simulation device, A network simulation method for performing evaluation by network connection verification on the evaluation device, wherein the simulation apparatus includes various node data installed in the virtual environment, and at least topology data, routing control algorithm data, traffic data, Generating the network model; receiving the predetermined data transmitted from the requesting terminal to the evaluation device by the simulation device; and Converting into virtual data that can be distributed within the network, generating load data for the evaluation device for the purpose of generating a load in the network model, and the converted virtual data and the generated load A step of performing interface processing for sending data into the network model, and setting various parameters as frame data to be executed by the data link layer protocol for the virtual data and load data distributed in the network model. Managing the behavior of the event as an event, and in the network model, when skipping an actual event process, adjusting the time by a clock synchronization process that sets the time required for the event process as a standby time, and Virtual Interface processing for capturing data and generated load data from within the network model, converting the captured virtual data into data receivable by the evaluation device, and converting the converted data to Transmitting to the evaluation device; and performing network connection verification of the evaluation device from the behavior of the virtual data.

The present invention may also be provided as a program that allows a computer to function as the simulation apparatus.

As is apparent from the above description, the network simulation system, the network simulation method, and the network simulation program according to the present invention are configured so that the object to be simulated in the network model is the data link layer (second layer of the OSI reference model) or the network. Since the frame processing of the interface layer (the first layer of the TCP / IP protocol) can be extended, the evaluation items of the evaluation device are increased in series, and there is an effect that the accuracy of connection verification is improved.

  In addition, the data to be input into the network model is data other than data that generates traffic, that is, past actual measurement data, data in which trouble has occurred in the past, prototype data, competitor data, confidential data, etc. From this point of view, the accuracy of connection verification is improved.

Referring to FIG. 1, reference numeral 1 denotes a simulation apparatus constituting a simulation system according to the present invention. In the present embodiment, the simulation apparatus 1 is a personal computer in which a program to be described later is installed to function as a simulation apparatus. However, the present invention is not limited to this form. May be specially manufactured.

In the present embodiment, the form in which data to be evaluated is transmitted from the requesting terminal t to the evaluation device d (for example, a multifunction peripheral) via the simulation apparatus 1 is described. However, the present invention is limited to this form. is not.

When the evaluation device d is a multifunction device, the predetermined data transmitted from the request terminal t is, for example, data for requesting printing of data created by a predetermined application in the request terminal t to a remote multifunction device. .

  The simulation apparatus 1 includes a CPU 11 that controls execution of a program, data reception, calculation, processing, and output, a memory 12 that temporarily stores data to be processed by the CPU 11, a program used for the processing, and the like. As an interface between the OS 131 that provides basic functions commonly used in application programs and the like, the driver 132, and the hard disk 13 that stores the simulation program 133 according to the present invention, and the request terminal t and the simulation apparatus 1. The functioning NIC 14 and the NIC 17 that functions as an interface between the simulation apparatus 1 and the evaluation device d, the data receiving unit 15 that receives data transmitted from the requesting terminal t, and the data transmitted from the simulation apparatus 1 to the multifunction peripheral d Data transmitter It consists of 6.

  Data (for example, an Ethernet frame) transmitted from the requesting terminal t is received by the data receiving unit 15 of the simulation apparatus 1 via a NIC (Network Interface Card) 14 provided in the simulation apparatus 1. The NIC 14 is taken into the simulation apparatus 1 by the network communication driver 132 of the hard disk 13 (for example, “WinPcap” may be used as a Windows (registered trademark) driver).

  This data is received by the data receiving unit 15 and is taken into the simulation process by a predetermined API function provided from the OS 131.

When the predetermined process is completed in the simulation program 133, the data is transmitted from the data transmission unit 16 to the evaluation device d via the NIC 17.

FIG. 2 shows a simulation program 133 of the simulation apparatus 1 as a functional block diagram. For clarity of explanation, a part of the hardware configuration diagram of FIG. 1 is omitted, the same components are denoted by the same reference numerals, and detailed description thereof is omitted.

The data received by the data receiver 15 is converted by the first data converter 1331 as data that can be used in a virtual network model to be described later. This data is sent via a simulation engine interface 1333 to a simulation engine 1335 that provides a network model and manages the data and evaluates the connection of the network to the evaluation device d. After the data is distributed in the network model according to the predetermined routing control, it is captured again by the simulation engine interface 1333 and converted into data that can be received by the evaluation device d by the second data conversion unit 1336. The data is transmitted from the transmission unit 16 to the evaluation device via the NIC 14. Hereinafter, the data from the request terminal t before being converted by the first data converter 1331 and the data before being transmitted from the second data converter 1336 to the evaluation device d are referred to as “actual data”, and the first data conversion Data after the conversion by the unit 1331 and before the conversion by the second data conversion unit 1336 is referred to as “virtual data”.

By the way, in the simulation system, for the virtual data converted by the first data conversion unit 1331, up to the network layer (third layer of the OSI reference model) or the IP layer (third layer of the TCP / IP protocol). The execution of packet processing is limited to simulation, and frame processing at the data link layer (second layer of the OSI reference model) or network interface layer (first layer of the TCP / IP protocol) is ignored (or discarded). As a result, the fine granularity of data to be handled becomes coarse, and the accuracy of network connection verification is reduced.

FIG. 3 illustrates a protocol stack model in TCP / IP. That is, “application” in the application layer, “tpal”, “tcp”, “udp”, “rsvp” in the transport layer, “ip” and “arp” in the Internet layer, “mac” in the network interface layer, etc. It is formed in a shape.

On the data transmission side, data is sequentially transferred to the lower layer with the application layer as the upper layer, and “ip” is encapsulated (ip encapsulation) when transferred to the lower layer. This data is transmitted as a physical signal from the hub to the adjacent hub according to the mac address.

On the other hand, on the data receiving side, the data is transferred from the lower layer to the upper layer, and finally the data is executed by the “application”. It should be noted that the above encapsulation is released when it is transferred to an upper layer.

In this way, in an actual network, each protocol stack cooperates to process data, but in the virtual network model, if only focusing on the behavior of packet data, from “application” to “ip” in FIG. The simulation may be performed in the range of the protocol stack model A. However, on the premise that the evaluation device d is connected to a large-scale network or a complicated network, a highly accurate network simulation is necessary to prevent product reliability and rework. In the model, a faithful reproduction of the protocol stack is required.

Since the simulation apparatus 1 can distribute frame data that can be simulated up to the lower network interface layer (data link layer in the OSI reference model), that is, the protocol stack model B in FIG. The evaluation items of the evaluation device d for performing the process increase in series, and it is possible to improve the accuracy.

For example, in an actual bridge network, in order to prevent a broadcast storm, a loop in the network is automatically detected by an STP (Spaninng tree protocol) (not shown) belonging to the data link layer, and the loop is cut. At this time, a BPDU (bridge protocol data unit) is transmitted as a broadcast frame. Therefore, if the BPDU behavior in the network model is an evaluation target item, the accuracy of network connection verification is improved.

In general, data distributed in an actual network is composed of a header part, a payload part, and a tailor part. However, what is necessary for the simulation in the network model of the virtual environment is header information (destination information) and data length, and the actual data content does not need to be accurately reproduced in the payload portion.

Therefore, as shown in FIG. 4, the virtual data includes actual data R (actual data head portion Rh + actual data payload portion Rp + actual data tailor portion Rt) between the head portion Sh and the tail portion St. What should I do?

In an actual network, not only the actual data transmitted from the requesting terminal t but also data are transmitted from various requesting terminals to the evaluation device d, each of which has some influence on the network characteristics. Therefore, in order to perform highly accurate network connection verification, it is necessary to input these various data to the network model as much as possible.

In the present invention, in order to input the various data into the network model, a load data generation unit 1332 is provided, and the various data generated here are input to the simulation engine 1335 via the simulation engine interface 1333. It is configured. That is, the present invention is configured so that the actual data to be transmitted to the evaluation device d can be generated not only in the request terminal t of the actual machine connected to the simulation apparatus 1 but also in the simulation apparatus 1.

Here, the above-mentioned various data include, in addition to data input to generate traffic in the network model according to the set parameters, for example, past actual measurement data, data in which trouble occurred in the past, prototype Data, competitor data, confidential data, etc. The load data generation unit 1332 can easily generate a large amount of data, for example, by generating these data for the number of devices installed in the network model. Can be generated.

In the present invention, the load data is also frame data that can be simulated up to the network interface layer (data link layer in the OSI reference model), that is, the protocol stack model B in FIG. It can be distributed.

The simulation engine interface 1333 sends and captures the virtual data at the entrance / exit of the simulation engine 1335 as data to be distributed in the simulation model. Specifically, for example, a unique ID is assigned to a node (router or the like) virtually installed at the entrance of the network model provided by the simulation engine 1335, the ID is secured, and an event of virtual data transmission timing is assigned. By accumulating the event list managed by the event management unit 1335b, virtual data transmission and capture acceptance processing is performed.

The simulation engine 1335 performs generation of the network model, management of virtual data and load data, and evaluation of simulation results.

The network model is generated from an object management library 1335d storing various node data virtually installed in the network model and a network setting library 1335e composed of at least topology data, routing control algorithm data, and traffic data. Read and generate data. Here, the various types of node data include routers, switches, servers installed in the network model, evaluation devices installed in the network model in addition to the evaluation device to be evaluated, or the same type of devices. There may be.

The management of virtual data and load data is an event management unit 1335b that manages events (packet queuing, retransmission processing, etc.) that occur in the network model, data transmission timing and frequency, data size, etc. In order to obtain a probability distribution value by executing a large number of distributed values, a random number generator 1335a that randomly generates a parameter for distributing load data, and a simulation time management for repeating this random number process at a simulation time This is performed by the unit 1335c.

The simulation result is evaluated by a statistical processing unit 1335f that performs statistical processing such as a response time variation, a change in line throughput, a change in the number of retransmissions, a verification unit 1335g that performs network connection verification from the statistical processing result, This is implemented by a determination unit 1335h for determining bottlenecks in the network and determining the use status of network lines.

For example, a case where a large number of data flows simultaneously into a certain band is assumed as follows.
Line transmission, communication speed: 64 kbps
Data (packet) length: 8 bytes Number of data (packets): 2000

  At this time, since the data of 8 * 8 * 2000 = 128 kbps exceeds the capacity of the line 64 kbps, it is sent (FIFO) to the connection destination in order from the first received packet, but the remaining 64 kbps is queued as subsequent data. Since the preceding packet is dequeued after being transmitted, the transmission is delayed by several ms from the preceding packet. The amount of delay increases as the packets are accumulated in the second half of the waiting queue. In this case, the statistical processing 1335f records a delay time such as “where and what node or line”.

By the way, the data processing in the requesting terminal t and the evaluation device d operates in real time, and the data processing in the network model operates in virtual time. For example, event processing on the OS of the virtual server installed in the network model is skipped.

Therefore, when such event processing is skipped, inconsistency occurs between the actual operation time and the operation time in the network model, and an accurate simulation cannot be executed.

Therefore, when skipping actual event processing in the network model, the simulation apparatus 1 sets a time required for this event processing as a waiting time (in ms units), and sets a clock synchronization processing unit 1334 that adjusts the time. It may be provided and finely adjusted.

FIG. 5 shows a process flow diagram of the simulation method according to the present invention. Hereinafter, description will be given with reference to FIG.

When the simulation apparatus 1 receives predetermined real data transmitted from the requesting terminal t (S1), the simulation apparatus 1 converts this into virtual data (S2).

  Along with the conversion of the virtual data, data other than the virtual data distributed in the simulation model, that is, load data is generated (S3), and the virtual data and the load data are transmitted to the simulation engine 1335 via the simulation engine interface 1333. (S4).

  The virtual data and load data sent into the network model are subjected to simulation processing by the simulation engine 1335 (S5).

During the simulation process, there is a mismatch between the actual time required for processing actual data in the requesting terminal t and the evaluation device d and the virtual time required for processing virtual data in the network model. Whether or not time correction is necessary (S6). If time correction is necessary, the clock synchronization processing unit 1334 executes clock synchronization processing (S7). If clock synchronization processing is not necessary, it is determined whether time correction is necessary for the next simulation processing.

When the virtual data reaches the exit of the network model by the set routing, it is captured by the simulation engine interface (S8) and converted from virtual data to real data (S9).

  The converted actual data is transmitted to the evaluation device d (S10), and the simulation ends. Based on the data obtained by the simulation process during this time, statistical processing, verification based on the statistical processing result, and determination are performed (not shown).

Hardware configuration diagram of simulation system Functional block diagram of the simulation device Diagram showing the protocol stack model Diagram showing the basic structure of virtual data Diagram showing the processing flow of the simulation method

Explanation of symbols

1 Simulation device 11 CPU
12 Memory 13 Hard disk 14 NIC
15 Data receiver 16 Data transmitter 17 NIC
131 OS
132 driver 133 simulation program 1331 first data conversion unit 1332 load data generation unit 1333 simulation engine interface 1334 clock synchronization processing unit 1335 simulation engine 1336 second data conversion unit

Claims (8)

A network simulation system that transmits predetermined data to the evaluation device by a packet communication method from a requesting terminal through a simulation device that generates a network model, and performs evaluation by network connection verification on the evaluation device,
The simulation apparatus includes a network model configuration data storage unit used for generating the network model, and a network model generation unit that generates a network model under a virtual environment based on the configuration data selected from the configuration data storage unit. Receiving means for receiving the predetermined data from the requesting terminal; first converting means for converting the received data into virtual data that can be distributed in the network model; and receiving the virtual data by the evaluation device The evaluation device for the purpose of generating a load in the network model in addition to the virtual data and the second conversion means for converting the data into the second data; the transmission means for transmitting the converted data to the evaluation device; Load data generating means for generating request data for Network interface means for sending and capturing data and load data to and from the network model, various parameters of the virtual data and load data distributed in the network model are set, and the behavior of these data is managed as events Data management means, and evaluation means for performing network connection verification of the evaluation device from the behavior of the virtual data,
The network simulation system, wherein the virtual data and the load data are at least frame data implemented by a data link layer protocol. The evaluation means is a BPDU (bridge bridge) in STP (Spaninng tree protocol).
2. The network simulation system according to claim 1, which includes an evaluation of a behavior of a protocol data unit).   The configuration data storage means includes an object management library that stores various types of node data that are virtually installed in the network model, and a network setting library that includes at least topology data, routing control algorithm data, and traffic data. The network simulation system according to claim 1 or 2, characterized in that 4. The network simulation system according to claim 1, wherein the management unit includes a random number generation unit that randomly generates a parameter for distributing load data.   The simulation apparatus includes a clock synchronization processing unit that sets a time required for event processing as a standby time and performs time adjustment when skipping actual event processing in the network model. The network simulation system according to any one of claims 1 to 4.   The load data generation means generates various data distributed in an actual network in addition to data for generating traffic in the network model, and the data management means processes these data as necessary, 6. The network simulation system according to claim 1, wherein the network simulation system can amplify the load. A network simulation method for transmitting predetermined data to the evaluation device by a packet communication method from the requesting terminal via the network model generated as a virtual environment by the simulation apparatus, and performing evaluation by network connection verification on the evaluation device Because
The simulation apparatus generates the network model from various node data installed in the virtual environment and at least topology data, routing control algorithm data, and traffic data, and transmits from the requesting terminal to the evaluation device. Receiving the predetermined data by the simulation device, converting the predetermined data into virtual data that can be distributed in the network model, and generating the load in the network model Generating load data for the device; performing interface processing for sending the converted virtual data and the generated load data into the network model; and the virtual data distributed in the network model. Data and load data as frame data implemented by the data link layer protocol, setting various parameters, managing the behavior of these data as events, and skipping actual event processing in the network model A time adjustment by clock synchronization processing that sets the time required for the event processing as a standby time, an interface processing for capturing the virtual data and generated load data from within the network model, Converting the converted virtual data into data receivable by the evaluation device, transmitting the converted data to the evaluation device, and performing network connection verification of the evaluation device from the behavior of the virtual data And have Network simulation wherein the.   A program for causing a computer to function as the simulation apparatus.

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