JP7460933B2 - TOPOLOGY ESTIMATION SYSTEM, PACKET GENERATION DEVICE, TOPOLOGY ESTIMATION DEVICE, TOPOLOGY ESTIMATION METHOD, AND PACKET GENERATION PROGRAM - Google Patents

Description

The present invention relates to a topology estimation system, a packet generation device, a topology estimation device, a topology estimation method, and a packet generation program.

In network operation work, when a failure occurs, it is necessary to quickly identify the failure location and understand the impact based on configuration information including topology information such as information indicating mutual connection relationships among network devices. Furthermore, in order to maintain and operate a dynamically changing configuration due to addition, subtraction, switching, etc. of various components that construct a network, it is necessary to recognize accurate configuration information of the topology. As topology estimation methods, those disclosed in Patent Document 1 and Patent Document 2 are known.

Patent document 1 proposes a topology estimation method that compares time series data of transmitted and received traffic volumes obtained from each communication interface (communication IF) of a network device, and estimates the connection relationships between communication IFs based on the relationship between the packet transmission volume and the packet reception volume between each communication IF.

Patent document 2 proposes a topology estimation method in which data with different traffic volumes is transmitted from a transmitting communication IF, and the connection relationship between communication IFs is estimated based on the correlation with the traffic volume of the data received by the receiving communication IF.

Japanese Patent Application Publication No. 2014-49851 JP 2020-127160 A

However, in the method disclosed in Patent Document 1 mentioned above, since the difference in the traffic amount of each communication IF is compared, it is difficult to estimate the topology with high accuracy between communication IFs with a small amount of traffic, such as in a backup system. difficult. Further, in the method disclosed in Patent Document 2, depending on the upper limit of the band, it may not be possible to accurately allocate the traffic necessary for estimation, and there is a problem that the topology cannot be estimated with high accuracy.

The present invention has been made in view of the above circumstances, and its objectives are to provide a topology estimation system, a packet generation device, a topology estimation device, a topology estimation method, and a topology estimation system capable of estimating topology with high accuracy. Its purpose is to provide a packet generation program.

A topology estimation system according to one embodiment of the present invention is characterized in that it comprises a packet generating device that generates a test packet to which error information is added and outputs the test packet to a network, and a topology estimation device that, when the test packet is transmitted from one of a plurality of communication units connected to the network, acquires information on the test packet and information on a packet received by another communication unit, compares the information on the test packet with the information on the received packet, and estimates the connection relationship between the one communication unit and the other communication unit based on the comparison result.

A packet generation device according to one aspect of the present invention is a packet generation device that generates a topology estimation packet for estimating the topology of a network, and includes a packet setting unit that generates a test packet to which error information is added; The present invention is characterized in that it includes a transmission time setting section that sets information on a transmission time of the test packet in the test packet, and a test packet transmission section that outputs the test packet to the network.

A topology estimating device according to one aspect of the present invention is a topology estimating device that estimates the topology of a network having a plurality of communication units, and the information of a test packet to which error information is added serves as a transmission source of the test packet. The number of errors is calculated based on the information of the communication unit, the input unit that acquires the reception information of the packet received by at least one of the plurality of communication units, and the reception information acquired by the communication unit that received the packet. a maximum value calculation unit that extracts a packet with the maximum number of errors and calculates the reception time of the extracted packet; a comparison unit that compares the transmission time of the test packet with the reception time of the packet with the maximum number of errors; The communication device is characterized by comprising a connection determination unit that determines a connection relationship between communication units in the network based on a comparison result of the comparison unit.

A topology estimation method according to one aspect of the present invention includes the steps of generating a test packet with error information added thereto and outputting the test packet to a network; acquiring information on the test packet and information on a packet received by one of a plurality of communication units connected to the network when the test packet is transmitted from the other communication unit; and comparing the information on the test packet and the information on the received packet and estimating the connection relationship between the one communication unit and the other communication unit based on the comparison result.

One aspect of the present invention is a packet generation program for causing a computer to function as the packet generation device.

According to the present invention, it is possible to estimate the network topology with high accuracy.

FIG. 1 is a block diagram showing the configuration of a topology estimation system according to an embodiment of the present invention. FIG. 2 is an explanatory diagram showing a schematic configuration of a topology estimation system according to an embodiment of the present invention. FIG. 3A is an explanatory diagram showing the format of an IPv4 header. FIG. 3B is an explanatory diagram showing protocol numbers of IPv4. FIG. 4 is an explanatory diagram showing error information obtained from the standard MIB. FIG. 5A is a first partial diagram of a flowchart showing the processing procedure of the topology estimation system according to the embodiment of the present invention. FIG. 5B is a second partial diagram of the flowchart showing the processing procedure of the topology estimation system according to the embodiment of the present invention. FIG. 6 is a block diagram showing the hardware configuration of the packet generation device according to this embodiment.

[Configuration of this embodiment]
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a block diagram showing a configuration of a topology estimation system 100 according to an embodiment of the present invention. Fig. 2 is an explanatory diagram showing a schematic configuration of the topology estimation system according to an embodiment of the present invention.

First, a schematic process of the topology estimation system 100 according to this embodiment will be described with reference to FIG. 2. As shown in FIG. 2, the topology estimation system 100 according to the present embodiment includes communication interfaces (communication IFs) 4a1, 4a2, 4a3 possessed by two network devices (NW devices) 4a, 4b, and communication IFs 4b1, 4b2, 4b3. Estimate the topology showing the connection relationship between Although FIG. 2 shows two NW devices 4a and 4b to simplify the explanation, it is also possible to estimate the topology between three or more NW devices. For example, as shown in FIG. 1, four NW devices 4a to 4d may be provided.

The topology estimation system 100 generates a packet to which error information is intentionally added (hereinafter referred to as a "test packet"), and transmits the test packet from, for example, the communication IF 4a1 of the NW device 4a. Then, if the above test packet is received by the communication IF 4b2 of the NW device 4b at approximately the same time as the time when the test packet is transmitted from the communication IF 4a1, it is determined that the communication IF 4a1 and the communication IF 4b2 are in a connection relationship. do.

That is, the NW device includes a counter that counts the number of error information (hereinafter referred to as "number of errors") in addition to a counter that counts normal packets. During steady state, the number of errors included in transmitted packets hardly changes. In this embodiment, a test packet to which error information is intentionally added is generated. Thereafter, this test packet is transmitted from the communication IF of a NW device installed in the network whose topology is to be estimated, and it is determined whether error information is included in the packet received at another communication IF. Based on this determination result, the connection relationship between the communication IFs is determined. Furthermore, the topology of the entire network is estimated.

That is, if a test packet is received by another communication IF at approximately the same time as the source communication IF sends the packet, and if the number of errors in the received packet and the number of errors in the test packet match or are close to each other, the two communication IFs are determined to be mutually connected. The topology of the network device is estimated by acquiring the connection relationships between multiple communication IFs.

The configuration of the topology estimation system 100 according to this embodiment will be described in detail below with reference to Figure 1. As shown in Figure 1, the topology estimation system 100 includes a topology estimation device 1 and a packet generation device 2 that generates packets for topology estimation. The topology estimation system 100 according to this embodiment is connected to an equipment database (equipment DB) 5, and estimates a topology indicating the connection relationship between multiple communication IFs of each of multiple network devices registered in the equipment DB 5.

The topology estimation system 100 is also connected to the device information collection device 3 and the network 4 whose topology is to be estimated.

The network 4 includes a plurality of (four in the figure) NW devices 4a, 4b, 4c, and 4d. Each of the NW devices 4a to 4d includes a plurality of communication IFs. Note that the number of NW devices is not limited to four.

An IF list, which is a list of each communication IF in each of the NW devices 4a to 4d, is registered in the equipment DB 5. The equipment DB 5 also registers the estimation results when the topology of each communication IF is estimated by the topology estimation device 1.

The device information collection device 3 collects device information received at each communication IF of the network devices 4a to 4d, and outputs it to the IF information storage unit 41 and the packet setting unit 52. When a packet is received, the device information includes various information related to communication, such as the number of errors contained in the packet and the time the packet was received.

The topology estimation device 1 includes an information storage section 10, a processing section 20, and an input/output section 30 including an input section 31 and an output section 32.

The input unit 31 is connected to an input device (not shown) such as a keyboard or a touch panel, and receives input operations from a user. For example, a list of a plurality of communication IFs (hereinafter referred to as "IF list") input by an input device is obtained.

The input unit 31 also receives information on each NW device outputted from the device information collection device 3, that is, information on the test packet to which error information has been added, information on the communication IF (communication unit) that is the transmission source of the test packet, Various device information such as reception information of a packet received by at least one of the plurality of communication IFs is acquired. The acquired device information is output to an IF list storage section 11 and a determination candidate generation section 21, which will be described later.

The output unit 32 outputs topology information stored in the connection result storage unit 13 (described later), that is, topology information estimated by the topology estimation device 1, to the equipment DB 5.

The information storage unit 10 includes an IF list storage unit 11, a determination candidate list storage unit 12, and a connection result storage unit 13. The information storage unit 10 is composed of a RAM (Random Access Memory) (not shown) or the like.

The IF list storage unit 11 stores an IF list of at least one communication IF possessed by a plurality of (four in the figure) NW devices 4a to 4d. The IF list includes information on each communication IF possessed by each NW device 4a to 4d and information on packets received at each communication IF.

The judgment candidate list storage unit 12 stores a judgment candidate list in which pairs of communication IFs that are candidates for connection judgment are registered as judgment candidates.

The connection result storage unit 13 stores a connection list in which connection forms obtained as topology estimation results are registered. That is, information on a set of communication IFs determined to be mutually connected is registered as a connection form in the connection list. For example, in the example shown in FIG. 2, it is registered that the communication IF4a1 and the communication IF4b2 are connected, the communication IF4a2 and the communication IF4b3 are connected, and the communication IF4a3 and the communication IF4b1 are connected.

The processing unit 20 includes a determination candidate generation unit 21, a maximum value calculation unit 22, a comparison unit 23, and a connection determination unit 24.

The determination candidate generation unit 21 extracts a pair of communication interfaces that are candidates for determination, registers them in a determination candidate list, and stores them in the determination candidate list storage unit 12. Specifically, the determination candidate generation unit 21 generates information on pairs of communication interfaces for determining whether or not there is a connection relationship among multiple communication interfaces, and stores the information in the determination candidate list storage unit 12.

The set of communication IFs may be a combination of the communication IF that is the transmission source of the test packet and all other communication IFs, or may be a combination of arbitrary communication IFs. If the connection relationship between the communication IFs is not detected, the determination candidate generation unit 21 deletes the data of this combination from the determination candidate list storage unit 12.

The maximum value calculation unit 22 obtains the number of errors, which is a count value of error information detected in packets of each communication IF collected by the device information collection device 3, from the IF list storage unit 11. For example, in an interface group of a standard MIB (Management Information Base), in addition to traffic volume (octets), various information regarding normal packets and error information can be obtained, as shown in Figure 4. The maximum value calculation unit 22 employs this method to obtain the number of errors in communication between communication IFs.

The maximum value calculation unit 22 also extracts the packet with the maximum number of errors from the packets acquired for each communication IF in time series. For example, if three packets are received at the communication IF 4b1 of the NW device 4b shown in FIG. The packet indicated by code t3 with the largest number of errors is extracted. That is, the maximum value calculation unit 22 extracts the packet with the maximum number of errors based on the packet information acquired by the communication IF where the packet was received. Furthermore, the reception time of the extracted packet is acquired.

The comparison unit 23 compares the time when the packet extracted by the maximum value calculation unit 22, that is, the packet with the maximum number of errors, was received, and the transmission time of the test packet stored in the transmission information storage unit 42, which will be described later. Compare. The comparison unit 23 outputs this comparison result to the connection determination unit 24.

When the comparison unit 23 determines that the packet with the largest number of errors is received within a predetermined time from the transmission time of the test packet, the connection determination unit 24 connects the communication IF that received the packet with the largest number of errors; It is determined whether there is a connection relationship with the communication IF that is the transmission source of the test packet. At this time, the connection determination unit 24 determines whether or not there is a connection relationship with the set of communication IFs stored in the determination candidate list storage unit 12.

2, as an example, a test packet with error information added is transmitted from the packet generating device 2, and each of the communication IFs 4a1, 4a1, and 4a3 of the network device 4a transmits a test packet including information on the time and number of errors indicated by the symbols q1, q2, and q3, respectively. Then, each of the communication IFs 4b1, 4b2, and 4b3 of the network device 4b receives the illustrated packets.

In this case, the communication IF 4b1 receives the maximum number of errors at time 10:30:00 (denoted as "10:30:00" in the figure). On the other hand, as shown by code q3, at time 10:30:00, a test packet with error information added is transmitted from the communication IF 4a3. Therefore, it is determined that the communication IF 4a3 and the communication IF 4b1 are connected to each other.

Similarly, in communication IF4b2, the number of errors received at time 10:00:00 (indicated as "10:00:00" in the figure) is the largest. Also, as shown by symbol q1, at time 10:00:00, a test packet with error information added is sent from communication IF4a1. Therefore, it is determined that communication IF4a1 and communication IF4b2 are connected to each other.

Furthermore, in communication IF 4b3, the number of errors received at the time 10:15:00 (indicated as "10:15:00" in the figure) is the largest. Also, as shown by symbol q2, at the time 10:15:00, a test packet with error information added is sent from communication IF 4a2. Therefore, it is determined that communication IF 4a2 and communication IF 4b3 are connected to each other. That is, when a packet with the largest number of errors is received within a predetermined time from the transmission time of the test packet in comparison unit 23, connection determination unit 24 determines that there is a connection relationship between the communication IF that received the packet with the largest number of errors and the communication IF that is the source of the test packet.

Returning to Figure 1, the packet generating device 2 comprises an information storage unit 40, a processing unit 50, and an input/output unit 60.

The information storage unit 40 includes an IF information storage unit 41 and a transmission information storage unit 42.

The IF information storage unit 41 reads various types of information regarding the equipment DB output from the equipment DB 5. The IF information storage unit 41 also stores information regarding the communication IF included in the read information.

The transmission information storage unit 42 stores error information included in a test packet transmitted from a test packet transmission unit 62, which will be described later. Specifically, information such as information on the communication IF that transmitted the test packet, transmission time, and number of errors is saved.

The processing section 50 includes a transmission time setting section 51, a packet setting section 52, a port number setting section 53, and a header information description section 54.

The transmission time setting unit 51 sets the transmission time of the test packet to which a predetermined number of error information is added. Furthermore, when transmitting a plurality of test packets, the transmission times are set so that the transmission times of each test packet are different.

The packet setting unit 52 sets a test packet including the number of errors required for topology estimation. The packet setting unit 52 also generates each test packet by changing the number of errors for each communication IF that is the transmission source of the test packet.

A method for generating error packets will be described below. For example, an IP packet that adopts IPv4 (Internet Protocol version 4) has an IP payload in which transmission data is described and an IP header in which information about the transmission data is described, as shown in FIG. 3A. Furthermore, the IP header has a "protocol" field in which a protocol number is set, as indicated by p1. There are unused protocol numbers.

FIG. 3B is an explanatory diagram showing the correspondence between protocol numbers and protocols corresponding to each number. For example, protocol numbers "144 to 252" are empty numbers. The packet setting unit 52 generates a predetermined number of error information by intentionally assigning empty numbers to the protocol field.

Returning to FIG. 1, the port number setting unit 53 sets a port number for which the protocol is undefined among the multiple port numbers included in each communication IF. If there are multiple undefined port numbers, any one of these port numbers is set.

The header information description unit 54 specifies the port number selected by the port number setting unit 53 when generating a test packet to which error information is added.

The input/output section 60 includes a port information input section 61 and a test packet transmission section 62.

The port information input unit 61 acquires information on port numbers with undefined protocols in packets transmitted from each communication IF of each of the NW devices 4a to 4d, and outputs the information to the port number setting unit 53 described above.

The test packet transmitting unit 62 transmits the test packet generated by the packet setting unit 52, that is, the test packet to which error information is intentionally added, to at least one of the plurality of NW devices 4a to 4d installed in the network 4. Output in one. The test packet is transmitted from the communication IF of a desired NW device to the communication IF of another NW device. The test packet transmitter 62 also transmits information such as the communication IF that transmitted the test packet, the transmission time, and the number of errors to the transmission information storage section 42 .

[Operation of this embodiment]
Next, the processing procedure of the topology estimation system 100 according to this embodiment will be explained with reference to the flowcharts shown in FIGS. 5A and 5B.

First, in step S11 in FIG. 5A, the IF list registered in the equipment DB 5 is read out and stored in the IF information storage unit 41 under the control of the processing unit 50 of the packet generation device 2. For example, information on the communication IFs 4a1, 4a2, and 4a3 of the NW device 4a and information on the communication IFs 4b1, 4b2, and 4b3 of the NW device 4b shown in FIG. 2 are stored as an IF list in the IF information storage unit 41.

In step S<b>12 , the input unit 31 of the topology estimation device 1 acquires information on the communication IF that is the target of topology estimation, and stores it in the IF list storage unit 11 .

Next, the processing unit 50 generates a test packet to which error information is added. In step S13, the transmission time setting unit 51 sets the transmission time of the test packet. When generating a plurality of test packets, the transmission times are set so that the transmission times are different from each other. For example, when transmitting test packets from the communication IFs 4a1, 4a2, and 4a3 shown in FIG. 2, the transmission times are set with a time difference of 15 minutes.

In step S14, the packet setting unit 52 sets the required number of errors. For example, as shown by symbols q1 to q3 in FIG. 2, the number of errors is set to "100". Further, the packet setting unit 52 generates a test packet to which 100 pieces of error information are added. The error information can be added by specifying an option with "iperf", which is a method of intentionally assigning a blank number to the protocol field in IP packets that use IPv4, or by using "hping". etc. can be adopted. The packet setting unit 52 also generates a test packet to which a predetermined number of error information is added.

In step S15, the port number setting unit 53 selects an undefined port number from among the multiple ports included in the communication IF from which the test packet is sent.

In step S16, the header information description unit 54 specifies the port number selected in the processing of S15.

In step S17, the test packet transmitting unit 62 transmits the test packet to the desired network device (the source network device) among the network devices 4a-4d installed in the network 4. The communication IF of the source network device (e.g., communication IF 4a1 shown in FIG. 2) transmits the test packet to the communication IF of another network device (e.g., communication IF 4b1 shown in FIG. 2). As a result, the test packet is received by the communication IF of the other network device. Information on the packets received by each network device 4a-4d is collected by the device information collecting device 3.

In step S18, the test packet transmitting unit 62 generates a transmission list of test packets with the error information added. A "transmission list" is a list that describes information that corresponds the communication IF name, the transmission time of the test packet, and the number of errors contained in the test packet. For example, it is a list that describes the information shown by symbols q1 to q3 in Figure 2. The generated transmission list is stored in the transmission information storage unit 42.

In step S19 shown in FIG. 5B, the processing unit 20 of the topology estimation device 1 determines, based on the information of the communication IF that transmitted the test packet stored in the transmission information storage unit 42 and the information of the communication IF that received the packet output from the device information collection device 3, whether the communication IF that is the sending side and the communication IF that is the receiving side are included in the list of communication IFs to be estimated stored in the IF list storage unit 11 of the topology estimation device 1.

If so (S19; YES), in step S20, the maximum value calculation unit 22 calculates the time when the number of errors contained in the packet received by the communication IF to be estimated is the maximum. For example, in the communication IF 4b1 shown in FIG. 2, as shown by the symbol t3, it is recognized that the number of errors contained in the packet received at the time "10:30:00" is the maximum.

In step S21, the comparison unit 23 refers to the transmission information storage unit 42 and compares the transmission time of the test packet transmitted from the test packet transmission unit 62 with the reception time of the packet calculated by the maximum value calculation unit 22.

In step S22, the connection determination unit 24 checks whether a combination of a communication IF that will be the sending side and a communication that will be the receiving side is set in the determination candidate list storage unit 12, and if it is set, calculates the connection relationship between the communication IFs based on the comparison result by the processing of S21. For example, as shown by symbol q1 in Figure 2, if a test packet is sent from communication IF 4a1 of NW device 4a at time 10:00:00 and the number of errors contained in the packet received by communication IF 4b2 of NW device 4b is the maximum, it is determined that communication IF 4a1 and IF 4b2 are connected to each other.

In step S23, the connection determination unit 24 stores information on the connection relationship determined in the processing of S22 in the connection result storage unit 13.

In step S24, the output unit 32 outputs the connection relationship information stored in the connection result storage unit 13 to the equipment DB 5 and reflects it in the equipment DB 5. Then, this process is terminated.

On the other hand, if it is determined in the process of S19 that the communication IFs of the sending and receiving sides are not set in the IF list storage unit 11 (S19; NO), in step S25, the determination candidate generation unit 21 deletes the communication IF from the data of the communication IF stored in the determination candidate list storage unit 12. In other words, if the communication IF through which the test packet was received is not the communication IF to be estimated, there is no need to calculate the connection relationship, so the data of this communication IF is deleted. Then, this process is terminated. In this way, the connection relationship between the communication IFs included in the network 4 can be obtained by simple processing.

[Effects of this embodiment]
As described above, the topology estimation system according to the present embodiment includes a packet generation device that generates a test packet with error information added and outputs it to a network, and a plurality of communication units (communication IF) connected to the network. , when the test packet is transmitted from one communication unit, the information of the test packet and the information of the packet received by the other communication unit are acquired, and the information of the test packet and the received packet are obtained. and a topology estimating device that compares information of and estimates a connection relationship between the one communication unit and the other communication unit based on the comparison result.

In this embodiment, the packet generation device 2 intentionally generates a test packet to which a predetermined number of error information is added, and transmits this test packet from one communication IF installed in the network 4. Furthermore, the connection relationship between communication IFs is estimated based on error information included in packets received at other communication IFs.

That is, based on the error information added to a test packet sent from one communication IF and the error information included in a packet received by another communication IF, if the two pieces of information match or are similar, it is determined that there is a connection relationship between them and the topology of the entire network 4 is estimated. Therefore, it is possible to easily estimate the connection relationship between communication IFs, and therefore it is possible to easily estimate the topology of the entire network.

Furthermore, since the connection relationship between communication IFs is estimated by adding error information that rarely occurs in normal times, it is possible to estimate the topology with high accuracy.

Furthermore, the protocol included in the communication IF from which the test packet is sent sets an undefined port number, and the test packet is sent using this port number, making it possible to send the test packet with simple operations.

In addition, the sending time of a test packet sent by one communication IF is compared with the receiving time of the packet received by another communication IF, and if the test packet is received within a certain time from the sending time of the test packet, it is determined that there is a connection between the two, making it possible to estimate the topology with higher accuracy.

Furthermore, when multiple packets are received at any communication IF, the maximum value calculation unit 22 of the topology estimation device 1 extracts the packet with the largest number of errors, and calculates the reception time of the extracted packet and the test packet. The connection relationship between communication IFs is estimated by comparing the transmission times of . Therefore, even if a plurality of packets are received at any communication IF, the packet corresponding to the test packet can be extracted, making it possible to estimate the topology with high accuracy.

[Description of Modifications]
Next, a modified example of the above-mentioned embodiment will be described. In the above-mentioned embodiment, a connection relationship between communication IFs is estimated by comparing the transmission time of a test packet by one communication IF with the reception time of the packet received by another communication IF. In contrast, in the modified example, the connection relationship between one communication IF and another communication IF is estimated by changing the number of errors added to the test packet.

Specifically, a plurality of test packets each having a different number of errors are transmitted from one communication IF. For example, it is assumed that the number of errors added to the test packet transmitted from the communication IF 4a1 shown in FIG. 2 is "100", and the number of errors added to the test packet transmitted from the communication IF 4a2 is "200".

The comparison unit 23 shown in Fig. 1 estimates the connection relationship between the communication IFs based on the number of errors contained in packets received by other communication IFs. For example, if the number of errors contained in a packet received by communication IF4b2 shown in Fig. 2 is "100", it can be estimated that communication IF4a1 and communication IF4b2 are in a connection relationship.

Similarly to the above-described embodiment, the topology estimation device according to the modified example can easily estimate the connection relationship between communication IFs, and in turn can easily estimate the topology of the entire network.

As shown in FIG. 6, the packet generation device 2 and topology estimation device 1 of this embodiment described above include, for example, a CPU (Central Processing Unit, processor) 901, a memory 902, a storage 903 (HDD: Hard Disk Drive, A general-purpose computer system including a solid state drive (SSD), a communication device 904, an input device 905, and an output device 906 can be used. Memory 902 and storage 903 are storage devices. In this computer system, each function of the packet generation device 2 and the topology estimation device 1 is realized by the CPU 901 executing a predetermined program loaded onto the memory 902.

Note that the packet generation device 2 and the topology estimation device 1 may be implemented by one computer, or may be implemented by multiple computers. Furthermore, the packet generation device 2 and the topology estimation device 1 may be virtual machines implemented in a computer.

Note that the program for the packet generation device 2 and the program for the topology estimation device 1 are stored in a computer-readable record such as an HDD, SSD, USB (Universal Serial Bus) memory, CD (Compact Disc), or DVD (Digital Versatile Disc). It can be stored on a medium or distributed over a network.

The present invention is not limited to the above-described embodiments, and many variations are possible within the scope of the invention.

1 Topology estimation device 2 Packet generation device 3 Device information collection device 4 Network 4a to 4d NW device 4a1 to 4a3 Communication IF (communication department)
4b1 to 4b3 Communication IF (communication department)
5 Equipment database (equipment DB)
10 Information storage unit 11 IF list storage unit 12 Determination candidate list storage unit 13 Connection result storage unit 20 Processing unit 21 Determination candidate generation unit 22 Maximum value calculation unit 23 Comparison unit 24 Connection determination unit 30 Input/output unit 31 Input unit 32 Output unit 40 Information storage section 41 IF information storage section 42 Transmission information storage section 50 Processing section 51 Transmission time setting section 52 Packet setting section 53 Port number setting section 54 Header information description section 60 Input/output section 61 Port information input section 62 Test packet transmission section 100 Topology estimation system

Claims (8)

a packet generation device that generates a test packet with error information added and outputs it to a network;
When the test packet is transmitted from one of the plurality of communication units connected to the network, information on the test packet and information on the packet received by the other communication unit are obtained, a topology estimation device that compares information on the test packet and information on the received packet and estimates a connection relationship between the one communication unit and the other communication unit based on the comparison result;
A topology estimation system comprising: The packet generating device includes:
a packet setting unit for generating a test packet to which the error information is added;
a port number setting unit that sets a port number for which a protocol is not defined and is included in the one communication unit;
having
2. The topology inference system according to claim 1, wherein the port number set by the port number setting unit is specified when the test packet is transmitted to a communication unit connected to the network. The packet setting unit changes the number of errors added to the test packet for each communication unit that is a transmission source of the test packet,
The topology estimation system according to claim 2, wherein the topology estimation device estimates a connection relationship between the one communication unit and the other communication unit based on the number of errors. the packet generation device includes a transmission time setting unit that sets a transmission time of the test packet;
The topology estimation system according to any one of claims 1 to 3, characterized in that the topology estimation device estimates a connection relationship of the communication units based on a comparison result between a time when the test packet is transmitted from the one communication unit and a time when the test packet is received by the other communication unit. A packet generating device that generates a topology estimation packet for estimating a topology of a network, comprising:
a packet setting unit for generating a test packet to which error information is added;
a transmission time setting unit that sets information on a transmission time of the test packet in the test packet;
a test packet transmitting unit that outputs the test packet to the network;
A packet generating device comprising: A topology estimation device that estimates a topology of a network having a plurality of communication units, comprising:
an input unit that acquires information on a test packet to which error information has been added, information on a communication unit that is a transmission source of the test packet, and reception information on a packet received by at least one of the plurality of communication units;
a maximum value calculation unit that extracts a packet with a maximum number of errors based on reception information acquired by a communication unit that receives the packet, and calculates a reception time of the extracted packet;
a comparison unit that compares a transmission time of the test packet with a reception time of the packet with the maximum number of errors;
a connection determination unit that determines a connection relationship of communication units in the network based on a comparison result of the comparison unit;
A topology estimation device comprising: generating a test packet with error information added thereto and outputting the test packet to a network;
When the test packet is transmitted from one of a plurality of communication units connected to the network, information on the test packet and information on packets received by the other communication units are acquired;
comparing information of the test packet with information of the received packet, and estimating a connection relationship between the one communication unit and the other communication unit based on a result of the comparison;
A topology estimation method comprising: A packet generation program for causing a computer to function as the packet generation device according to claim 5.

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