Patent ID: 12237976

DESCRIPTION OF EMBODIMENTS

Summary of the Invention

In a situation in which the traffic volumes are constant or the traffic volumes have no characteristic changes (for example, there are a plurality of network devices with a similar tendency of the traffic volume), use of the conventional technique makes it difficult to identify the correct opposing device.

Therefore, as shown inFIG.1, the present invention adds different sizes of packets PA1, PA2, . . . , PB1, PB2, . . . to the interfaces of the adjacent network devices and the like, respectively. This may form a characteristic amount in the traffic volumes, thereby making it possible to correctly understand the connection relationship of the interfaces from the correlation of the traffic volumes.

One embodiment to practice the present invention will be described below using the drawings.

<Example System Configuration>

FIG.2illustrates an example configuration of a topology estimation system1according to this embodiment. As shown inFIG.2, the topology estimation system1is configured by including mainly a topology estimation device10, a traffic addition device50, and a traffic collection device90. In the topology estimation system1, the topology estimation device10estimates how a plurality of network devices A to F included in a predetermined to-be-estimated network N are connected, in other words, the connection relationship (topology) of a plurality of interfaces of the plurality of network devices A to F.

The topology estimation device10as shown inFIG.2is the same as the topology estimation device10shown in FIG. 1 of PTL 2. Note that, in this embodiment, a traffic addition determination unit11is added between a connection form generation unit (23) and a traffic volume calculation unit (24). The parenthetical reference numerals as shown inFIG.2are the same as the reference numerals in [PTL 2]. In addition, among the connecting lines between the function units shown in FIG. 1 in PTL 2,FIG.2only show the main lines in processing in broken lines and omits other connecting lines. InFIG.2, this embodiment is characterized by the dotted function units and the solid connecting lines.

<Example Configuration of Traffic Addition Device>

In the system configuration shown inFIG.2, this embodiment adds the traffic addition device50to the system configuration in PTL 2. Therefore, first, an example configuration of the traffic addition device50will be described.

As shown inFIG.2, the traffic addition device50is configured by including mainly a setting input unit51, a traffic generation unit52, a traffic transmission unit53, a traffic information storage unit54, and a destination interface storage unit55.

The setting input unit51has a function of reading traffic information from the traffic information storage unit54. The setting input unit51also has a function of calculating traffic volumes to be flowed additionally through the interfaces of the plurality of network devices A to F included in the to-be-estimated network N, respectively, according to the traffic volumes of the to-be-estimated network N included in the traffic information.

Specifically, the setting input unit51has a function of calculating, according to the traffic volumes flowing through the plurality of interfaces of the plurality of network devices A to F, additional traffic volumes to be added to the traffic volumes, respectively. In so doing, the setting input unit51calculates such that the additional traffic volumes to be added to the traffic volumes are different at the interfaces.

The traffic generation unit52has a function of generating the traffic volumes different at the interfaces, which are calculated by the setting input unit51. Here, the traffic means data (information) flowing through a network. This embodiment is directed to a network device. So, the traffic generation unit52generates packets of different data sizes at the interfaces. Note that this embodiment may also be directed to a server device other than the network device and thus may change the data size of a segment instead of the packet.

The traffic transmission unit53has a function of transmitting the packets of different data sizes at the interfaces generated by the traffic generation unit52to the plurality of network devices A to F, respectively. The traffic transmission unit53also has a function of allowing the packets to be output from the interfaces of the plurality of network devices A to F.

In other words, the traffic transmission unit53adds to the traffic volumes output from the plurality of interfaces of the plurality of network devices A to F the additional traffic volumes different at the interfaces generated by the traffic generation unit52.

The traffic information storage unit54has a function of storing the traffic information of the to-be-estimated network N such that they may be read out therefrom. Specifically, the traffic information storage unit54stores the traffic and its volume flowing through the plurality of interfaces of the plurality of network devices A to F such that they may be read out therefrom as the traffic information.

The destination interface storage unit55has a function of associating an interface ID of the destination to which the traffic volume is added by the traffic transmission unit53transmitting the packets with the network device ID and storing them as destination information that may be read out therefrom.

An example configuration of the traffic addition device50has been described above. Note that the setting input unit51, the traffic generation unit52, and the traffic transmission unit53correspond to “a traffic volume calculation unit” and “a traffic addition unit” in the claims, respectively.

<Example Configuration of Topology Estimation Device>

Next, an example configuration of the topology estimation device10will be described. As described in PTL 2, the topology estimation device10is a device that estimates, from a correlation of the traffic volumes at a plurality of interfaces of a plurality of network devices, a connection relationship of the interfaces (topology). In this embodiment, the topology estimation device10is configured by further including a traffic addition determination unit11in addition to the configuration described in PTL 2.

The traffic addition determination unit11functions between the connection form generation unit (23) and the traffic volume calculation unit (24). The traffic addition determination unit11has a function of determining whether to add additional traffic volumes to the traffic volumes of the to-be-estimated network N according to changes of the traffic volumes of the to-be-estimated network N before calculating and estimating the topology of the to-be-estimated network N.

Specifically, the traffic addition determination unit11determines whether to add additional traffic volumes to the traffic volumes according to changes of the traffic volumes flowing through the plurality of interfaces of the plurality of network devices A to F.

An example configuration of the topology estimation device10has been described above. Note that although this embodiment is described with respect to the topology estimation device10including the traffic addition determination unit11, the traffic addition device50may include the traffic addition determination unit11. Refer to the description in PTL 2 for other things including the function units except the traffic addition determination unit11.

<Traffic Collection Device>

Next, the traffic collection device90will be described. The traffic collection device90has a function of collecting traffic information from the to-be-estimated network N. Specifically, the traffic collection device90collects the traffic and its volume flowing through the plurality of interfaces of the plurality of network devices A to F, and transmits them to an input unit (31) of the topology estimation device10along with the acquired time (time stamp) of each set of the traffic information.

<Examples of Method of Adding Traffic Volume/Method of Varying Additional Traffic Volume>

Next, examples of a method of adding a traffic volume and a method of varying an additional traffic volume will be described. The traffic generation unit52and the traffic transmission unit53in the traffic addition device50perform the traffic volume addition process and the traffic volume variation process.

As shown inFIG.3, methods of adding a traffic volume to the plurality of adjacent network devices A to F include, for example, the traffic addition device50remote logging in the network device E using Telnet and the like and flowing packets in the adjacent network devices A, C, D, F using the ping and the like.

Methods of varying the additional traffic volume include, for example, changing the additional traffic volume by varying the data size per one packet. The ping may specify any data size of a packet and specify different data sizes at the interfaces calculated by the setting input unit51. InFIG.3, the additional traffic volume may be added to the traffic volume that is output from the network device E to the network device A by performing “ping -l 100 ip. addr_A_sby”. The value of “100” is the data size of a packet. Likewise, the additional traffic volume may be added to the traffic volume that is output from the network device E to the network devices C, D, and E by performing “ping -l 200 ip. addr_C_sby”, “ping -l 300 ip. addr_D_sby”, “ping -l 400 ip. addr_E_sby”, respectively.

This may provide a characteristic amount in the traffic volumes output from the interfaces of the network device E. Note that the traffic volume may be added by a user using an Operation System (OpS) or by the traffic addition device50executing a script of the ping command.

<Example of Method of Calculating Additional Traffic Volume>

Next, an example of a method of calculating an additional traffic volume will be described. The setting input unit51in the traffic addition device50performs the additional traffic volume calculation process.

Here, as shown inFIG.4, the average traffic volume flowing through the interfaces of the non-active devices may not always be the same value. Then, it is necessary to vary the additional traffic volume on the basis of the volume that is flowing steadily. The base values include the average, the maximum, the minimum, and the median, etc.

For example, according to the average of the traffic volume that is flowing steadily through the active devices, calculation is performed to add a traffic volume as any X [%] to the average traffic volume. Specifically, it is assumed that for IF (IF_Y1, IF_Y2. . . ) of the network device Y, the original flowing traffic volume is IF_Yi(t) (i=1, 2 . . . ). In so doing, new IF_Yi(t), which is the traffic volume flowing through the IF when the additional traffic volume is added, may be calculated by formula (1). Note that add_IF_Yiindicates the added traffic volume.
[Formula 1]
new IF_Yi(t)=add_IF_Yi+IF_Yi(t)  (1)where add_IF_Yi=X [%]×mean{new IF_Yi-1(t)} (i>1)add_IF_Yi=0 (i=1)
<Example of Method of Determining Traffic Volume Addition>

Next, an example of a method of determining traffic volume addition will be described. The traffic addition determination unit11in the topology estimation device10performs the process of determining traffic volume addition.

The traffic addition determination unit11determines whether to add a traffic volume according to changes of the traffic volumes of the network input to the topology estimation device10. A non-activated device is automatically switched to an activated device if abnormality occurs in the activated device. It is thus not necessary to flow additional traffic volume after being switched to the activated device. After being switched, it is necessary to add a traffic volume to the non-activated device that has changed to a different device. Thus, as shown inFIG.5, the need to add a packet is determined by, for example, according to the waveform (variation) of the traffic volume. Specifically, if the standard deviation of the traffic volume in a predetermined time is below a threshold, the calculated traffic volume to be added is flowed additionally and if the standard deviation is above the threshold, no traffic volume is added. In addition to the standard deviation or alone, according to the slope of the waveform change of the traffic volume, the additional traffic volume may be added if the slope is positive and the additional traffic volume may not be added if the slope is negative.

<Example Operation of Topology Estimation System>

Next, a traffic volume addition method performed by the topology estimation system1will be described.FIG.6illustrates a process flow of the traffic volume addition method.Step S1: First, the traffic collection device90collects, from the plurality of network devices A to F included in the to-be-estimated network N, the traffic volumes flowing through the plurality of interfaces of the plurality of network devices A to F. Then, the traffic collection device90transmits to the input unit (31) in the topology estimation device10the collected traffic information along with its time stamp.Step S2: Next, if the topology estimation device10receives the traffic information from the traffic collection device90, the traffic addition determination unit11determines whether to add an additional traffic volume to the traffic volumes according to the time change of the traffic volumes flowing through the plurality of interfaces of the plurality of network devices A to F. For example, the traffic addition determination unit11determines to add the traffic volume if the standard deviation of each traffic volume is below a threshold. In addition, the traffic addition determination unit11determines not to add the traffic volume if the standard deviation of each traffic volume is equal to or more than the threshold. In so doing, the topology estimation device10may determine whether to add the traffic volume according to the slope of the waveform change of the traffic volumes. If it is determined not to add the traffic volume, then control skips steps S3to S9and passes to step S10.Step S3: If it is determined to add the traffic volume, then the traffic addition determination unit11transmits the traffic information received from the traffic collection device90to the traffic addition device50. The traffic addition device50stores the traffic information in the traffic information storage unit54.Step S4: Next, the setting input unit51in the traffic addition device50reads and refers to the traffic information from the traffic information storage unit54. The setting input unit51then calculates, according to the traffic volumes flowing through the plurality of interfaces of the plurality of network devices A to F, the additional traffic volumes to be added to the traffic volumes such that different traffic volumes are provided at the interfaces.Step S5: Next, then the traffic generation unit52generates the different traffic volumes at the interfaces calculated at step S4. For example, the traffic generation unit52generates packets of different data sizes at the interfaces.Step S6: Next, the traffic transmission unit53transmits the packets of different data sizes at the interfaces generated at step S5to the plurality of network devices A to F in the to-be-estimated network N and allows the packets to be output from the interfaces of the plurality of network devices A to F.Step S7: Next, then the traffic transmission unit53associates the network device IDs of the destinations to which the packets are transmitted at step S6with the interface IDs and stores them as the destination information in the destination interface storage unit55.Step S8: Next, the traffic collection device90recollects the traffic volumes flowing through the plurality of interfaces of the plurality of network devices A to F from the plurality of network devices A to F included in the to-be-estimated network N.Step S9: Next, the traffic collection device90transmits the traffic information recollected at step S8to the input unit (31) in the topology estimation device10.Step S10: Subsequently, when the topology estimation device10re-receives the traffic information from the traffic collection device90, the traffic volume calculation unit (24) and the like calculates and estimates the topology of the to-be-estimated network N using the re-received traffic information.Step S11: Finally, the output unit (32) of the topology estimation device10displays the topology of the to-be-estimated network N that is calculated and estimated at step S10on a monitor and stores it in a file.

Effects of Embodiment

Finally, the effects of this embodiment will be described. According to this embodiment, the traffic addition device50adds to the traffic volumes output from the plurality of interfaces of the plurality of network devices A to F in the to-be-estimated network N additional traffic volumes different at the interfaces. This may form a characteristic amount in the traffic volumes so that the topology estimation device10may correctly understand the connection relationship of the interfaces from the correlation of the traffic volumes.

Note that the topology estimation device10, the traffic addition device50, and the traffic collection device90described in this embodiment may be provided by a computer that includes components such as a CPU, a memory, an input/output interface, and a communication interface. In addition, a program to allow a computer to function as those devices and a storage medium of the program may also be provided.

REFERENCE SIGNS LIST

1Topology estimation system10Topology estimation device11Traffic addition determination unit50Traffic addition device51Setting input unit52Traffic generation unit53Traffic transmission unit54Traffic information storage unit55Destination interface storage unit90Traffic collection device