Network control device, network control method, and network control program

Abstract

A network control device (10) acquires, for example, from network monitoring information, network monitoring information for a time slot in which the usage rate of a physical interface band is 70% or more (time slot in which traffic is congested). The network control device (10) then acquires, from the acquired network monitoring information, a use band for high-priority traffic in the time slot, the number of simultaneously connected users, and the like. Next, for example, the network control device (10) recalculates the CIR and the PIR on the basis of a band obtained by subtracting, from the usable band of the physical interface, the average high-priority traffic use band in the time slot, and the average of the number of users allocated to the physical interface and the number of simultaneously connected users. Then, the network control device (10) resets the CIR and the PIR of an edge router (20) using the recalculated CIR and the PIR.

Description

Network control device, network control method, and network control program

[0001] The present invention relates to a network control device, a network control method, and a network control program for configuring an edge router with QoS (Quality of Service) control settings.

[0002] Conventionally, there are technologies that achieve fairness (provision of equal communication capacity) in communication among users in best-effort traffic at the physical IF (interface) of an edge router. For example, there is a technology that colors packets of traffic of each user (each VLAN (Virtual LAN)) with green, yellow, or red using trTCM (two rate three color marker) according to the bandwidth used by the traffic of that user, and performs QoS control based on the priority corresponding to the packet color (green, yellow, or red).

[0003] In the above-mentioned trTCM, the traffic packets of each user are colored (Green, Yellow, Red) using the Committed Information Rate (CIR) and Peak Information Rate (PIR) of the traffic of each user. In the prior art, it is assumed that the CIR and PIR values ​​used in the trTCM are values ​​set by an operations manager or the like.

[0004] JP 2012-165221 A

[0005] RFC2859 "A Time Sliding Window Three Color Marker (TSWTCM)", [online], [Retrieved August 14, 2023], Internet <URL: https: / / datatracker.ietf.org / doc / html / rfc2859> Hongjun Su et al., "ItswTCM: A New Aggregate Marker to Improve Fairness in DiffServ", GLOBECOM'01. IEEE Global Telecommunications Conference (Cat. No.01CH37270), Nov. 2001., [online], [Retrieved August 14, 2023], Internet <URL: https: / / ieeexplore.ieee.org / stamp / stamp.jsp?tp=&arnumber=965893>

[0006] However, the CIR and PIR set by the operations manager as described above are not based on observed data of traffic on the physical IF, and therefore are not necessarily appropriate. Therefore, an object of the present invention is to calculate appropriate values ​​of CIR and PIR to be used in the trTCM based on observed data of traffic on the physical IF.

[0007] In order to solve the above-mentioned problems, the present invention is characterized by comprising a first acquisition unit that acquires time series data of the bandwidth used and the number of simultaneously connected users in a physical interface that accommodates traffic from multiple users; a second acquisition unit that acquires, based on the acquired time series data, the bandwidth used in the physical interface, the bandwidth used by traffic with a priority equal to or higher than a predetermined value, and the number of simultaneously connected users during a time period when the bandwidth usage rate of the physical interface is equal to or higher than a predetermined value; a calculation unit that uses a trTCM (two rate three color marker) to color packets of the traffic on a user traffic basis, and calculates a CIR (Committed Information Rate) and a PIR (Peak Information Rate) to be used in the trTCM in an edge router that performs QoS control, based on the bandwidth used in the physical interface of traffic with a priority equal to or higher than a predetermined value during the time period, the number of users assigned to the physical interface, and the number of simultaneously connected users; and an output processing unit that outputs the calculated CIR and PIR.

[0008] According to the present invention, it is possible to calculate appropriate values ​​of CIR and PIR to be used in trTCM based on observed data of traffic on a physical IF.

[0009] FIG. 1 is a diagram showing an example of a process for applying WRED to packets colored by trTCM to perform QoS control. FIG. 2 is a diagram for explaining the available bandwidth of BE traffic. FIG. 3 is a diagram for explaining NW monitoring information acquired by a NW monitoring device. FIG. 4 is a diagram showing an example of a system configuration including a NW control device. FIG. 5 is a sequence diagram showing an example of a processing procedure executed by the system. FIG. 6 is a diagram showing an example of the configuration of a NW control device. FIG. 7 is a flowchart showing an example of a processing procedure executed by the NW control device. FIG. 8 is a flowchart showing an example of a processing procedure executed by the NW control device. FIG. 9 is a diagram showing an example of setting CIR and PIR. FIG. 10 is a diagram showing the distribution of packets of each color in C1 and C2 shown in FIG. 9. FIG. 11 is a diagram showing an example of setting CIR and PIR. FIG. 12 is a diagram showing a computer executing a NW control program.

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a description will be given of an embodiment of the present invention with reference to the drawings, but the present invention is not limited to the embodiment.

[0011] [Prerequisites] First, the prerequisites for the NW control device of this embodiment will be explained using Figure 1. In a network, a forwarding device that directly accommodates user terminals and servers is called an edge router. An edge router has multiple physical interfaces (IFs). Each physical IF accommodates the traffic of multiple users, separated by VLANs.

[0012] The network monitoring device records, for example, information (network monitoring information) about traffic passing through each physical interface of an edge router via a core network, and stores the information in a database (DB).

[0013] Focusing on the BE (best effort) traffic of one physical IF of an edge router, the traffic packets are colored, for example, by VLAN unit using the trTCM as Red (R), Yellow (Y), or Green (G). In addition, one queue for BE traffic is prepared for each physical IF, and QoS control is performed.

[0014] Network operators want to provide equal communication capacity to each user for BE traffic. Therefore, in order to perform QoS control in the queue for BE traffic in each VLAN, the edge router uses trTCM to classify traffic packets into the following three classes based on the traffic bandwidth used by each VLAN, and colors them as Red (R), Yellow (Y), or Green (G).

[0015] ・Green (G) when the bandwidth used is less than CIR ・Yellow (Y) when the bandwidth used is equal to or greater than CIR but less than PIR ・Red (R) when the bandwidth used is equal to or greater than PIR

[0016] For example, if CIR = 8Mbps and PIR = 16Mbps, when downloading the same 100MB file, the packets in the queue will look like this:

[0017] - If you download at less than 8Mbps and take more than 100 seconds, all packets will be green. - If you download at more than 8Mbps but less than 16Mbps, some packets will be colored green and yellow. - If you download at more than 16Mbps and take less than 50 seconds, some packets will be colored green, yellow, and red.

[0018] When traffic on a physical interface becomes congested, the edge router discards packets in the order of Red (R) → Yellow (Y) → Green (G) depending on the length of the queue.

[0019] Next, the bandwidth available for BE traffic will be explained using Figure 2. In addition to BE traffic, traffic of a QoS class with a priority level equal to or higher than a predetermined value (hereinafter referred to as "high-priority traffic") also communicates on the same physical IF. Therefore, the bandwidth available for BE traffic is the bandwidth available on the physical IF minus the bandwidth used by high-priority traffic, as shown in Figure 2.

[0020] Next, we will explain the network monitoring information acquired by the network monitoring device. The network monitoring information includes time-series data on the bandwidth used by the physical IF. For example, as shown in Figure 3, the network monitoring information includes time-series data on the bandwidth usage rate of the physical IF.

[0021] Furthermore, the NW monitoring information includes, for example, the bandwidth usage rate in each time period, as well as the number of simultaneously connected users, the number of simultaneously connected sessions, the ratio of the bandwidth used by high priority traffic, the ratio of the bandwidth used by BE traffic, and so on.

[0022] Since the purpose of the NW control device of this embodiment is to avoid congestion of the physical IF, it is sufficient to process data when the bandwidth of the physical IF is congested. Therefore, the NW control device processes NW monitoring information during a time period when the bandwidth usage rate of the physical IF is 70% or more, for example.

[0023] [System Configuration Example] Next, an example of a system configuration including the NW control device 10 will be described with reference to Fig. 4. For example, as shown in Fig. 4, the system includes a NW monitoring device, a DB, the NW control device 10, and an edge router 20. The NW monitoring device monitors the state of traffic relayed by the edge router 20 via the network, and stores NW monitoring information indicating the monitoring results in the DB.

[0024] Based on an instruction input from a network operator or the like, the NW control device 10 sets the initial values ​​of the CIR and PIR to be used for the trTCM in the edge router 20. Thereafter, the NW control device 10 recalculates the CIR and PIR using the network monitoring information stored in the DB, and updates the CIR and PIR of the edge router 20 with the recalculated CIR and PIR.

[0025] The edge router 20 then uses the trTCM based on the updated CIR and PIR to color packets of each user's traffic on the physical IF as Red (R), Yellow (Y), or Green (G).The edge router 20 then performs QoS control, including packet discarding, based on the packet coloring result (Red (R), Yellow (Y), or Green (G)) and the queue length.The QoS control here is performed using, for example, WRED (Weighted Random Early Detection).

[0026] The NW control device 10 acquires, for example, NW monitoring information from the NW monitoring information when traffic on a physical interface is congested (for example, a time period when the bandwidth usage rate is 70% or more).Then, the NW control device 10 acquires, from the acquired NW monitoring information, information such as the bandwidth used by high-priority traffic when traffic is congested and the number of simultaneously connected users.

[0027] Next, the NW control device 10 calculates the CIR and PIR based on, for example, the bandwidth obtained by subtracting the average bandwidth used by high-priority traffic during times of traffic congestion from the available bandwidth of the physical IF, the average number of users simultaneously connected to the physical IF, and the number of users allocated to the physical IF (the calculation method will be described in detail later).The NW control device 10 then updates the CIR and PIR of the edge router 20 using the calculated CIR and PIR.

[0028] In this way, the NW control device 10 can reconfigure the CIR and PIR of the edge router 20 in response to changes in the number of simultaneously connected users and the bandwidth usage rate of high-priority traffic when the bandwidth of the physical IF is congested.

[0029] [Example of Processing Procedure] Next, an example of the processing procedure executed by the system will be described with reference to Fig. 5. First, the NW monitoring device monitors the status of the edge router 20 (S1), collects NW monitoring information (S2: information collection), and stores it in the DB (S3: information storage). The NW monitoring device executes the above processing at predetermined intervals. As a result, NW monitoring information such as time-series data on bandwidth usage rates at physical IFs is stored in the DB.

[0030] For example, as shown in Figure 4, the DB stores network monitoring information for each monitored physical IF, which corresponds to the monitoring date and time of the physical IF, the number of simultaneously connected users at the monitoring date and time, the bandwidth used, the bandwidth used by high-priority traffic, etc.

[0031] Thereafter, the NW control device 10 periodically acquires NW monitoring information from the DB (S4: Acquire information), and recalculates the CIR and PIR using the NW monitoring information acquired in S4 (S5).The NW control device 10 then resets the CIR and PIR of the edge router 20 using the recalculated CIR and PIR (S6).

[0032] [Configuration Example] Next, a configuration example of the NW control device 10 will be described with reference to Fig. 6. The NW control device 10 includes, for example, an input / output unit 11, a communication unit 12, a storage unit 13, and a control unit 14.

[0033] The input / output unit 11 is an interface that controls the input and output of various data. The input / output unit 11 receives, for example, definition values ​​for when traffic is congested and physical IF information input by the operations manager of the NW control device 10.

[0034] The definition value for traffic congestion is, for example, a utilization rate of the bandwidth of a physical IF of 70% or more. The physical IF information is, for example, information indicating the available bandwidth (capacity) for each physical IF, the number of users assigned to the physical IF (maximum number of users that can be accommodated), etc., as indicated by reference numeral 131 in Fig. 6 .

[0035] The communication unit 12 is an interface for communicating with external devices via a network. For example, the communication unit 12 receives network monitoring information from a database and transmits CIR and PIR setting commands output by the control unit 14 to the edge router 20.

[0036] The storage unit 13 stores data, programs, etc. that are referenced when the control unit 14 executes various processes. The storage unit 13 is realized by a semiconductor memory element such as a random access memory (RAM) or a flash memory, or a storage device such as a hard disk or an optical disk.

[0037] For example, the storage unit 13 stores definition values, physical IF information, etc. received by the input / output unit 11. The storage unit 13 also stores the CIR and PIR setting values ​​of the edge router 20 (previous CIR and PIR setting values).

[0038] The control unit 14 is responsible for overall control of the NW control device 10. The functions of the control unit 14 are realized, for example, by a CPU (Central Processing Unit) executing a program stored in the storage unit 13.

[0039] The control unit 14 includes, for example, an information input receiving unit 141 , a first acquisition unit 142 , a second acquisition unit 143 , a calculation unit 144 , a determination unit 145 , and an output processing unit 146 .

[0040] The information input receiving unit 141 receives input of a definition value for when traffic is congested and physical IF information. The first acquiring unit 142 acquires NW monitoring information (time-series data including the bandwidth used by the physical IF and the number of simultaneously connected users of the physical IF) from the DB. For example, the first acquiring unit 142 accesses the DB at predetermined intervals to acquire the NW monitoring information.

[0041] The second acquisition unit 143 acquires NW monitoring information when traffic on a physical IF is congested from the NW monitoring information acquired by the first acquisition unit 142. For example, the second acquisition unit 143 acquires NW monitoring information for a time period when the bandwidth usage rate of the physical IF is equal to or greater than a predetermined value (e.g., 70% or greater) based on a defined value for when traffic is congested, from the NW monitoring information.

[0042] The calculation unit 144 calculates the CIR and PIR used in the edge router 20 based on the NW monitoring information acquired by the second acquisition unit 143. The CIR and PIR are calculated using a statistical value of the bandwidth used by high-priority traffic and a statistical value of the number of simultaneously connected users. Here, an example will be described in which the statistical value of the bandwidth used by high-priority traffic is the average value of the bandwidth used by high-priority traffic, and the statistical value of the number of simultaneously connected users is the average value of the number of simultaneously connected users.

[0043] For example, first, the calculation unit 144 calculates the average bandwidth used by high-priority traffic and the average number of simultaneously connected users when traffic on the physical IF is congested, from the NW monitoring information acquired by the second acquisition unit 143.

[0044] Next, the calculation unit 144 calculates the CIR based on the following formula (1): The calculation unit 144 also calculates the PIR based on the following formula (2): Note that the capacity of the physical IF and the maximum number of users that can be accommodated by the physical IF are values ​​indicated in the physical IF information.

[0045] CIR = (capacity of physical interface - average bandwidth used by high-priority traffic during traffic congestion) / maximum number of users accommodated...Equation (1)

[0046] PIR = (physical interface capacity - average bandwidth used by high-priority traffic during traffic congestion) / average number of simultaneously connected users during traffic congestion...Equation (2)

[0047] The determining unit 145 determines whether the difference between at least one of the CIR and PIR values ​​calculated by the calculating unit 144 and the previous set values ​​of the CIR and PIR is equal to or greater than a predetermined threshold.

[0048] The output processing unit 146 outputs the currently calculated CIR and PIR when the determination unit 145 determines that the difference between the previous CIR and PIR setting values ​​and at least one of the CIR and PIR calculated by the current calculation unit 144 is equal to or greater than a predetermined threshold. For example, the output processing unit 146 converts the CIR and PIR calculated by the current calculation unit 144 into commands for the edge router, and inputs the settings to the edge router 20.

[0049] Thereafter, the edge router 20 colors the packets of the traffic of each user according to the trTCM using the set CIR and PIR, and performs QoS control using the results of coloring the packets.

[0050] 7, an example of a processing procedure executed by the NW control device 10 will be described. For example, the information input receiving unit 141 of the NW control device 10 receives input of information such as a defined value for when traffic is congested (e.g., 70% of the capacity of the physical IF), thresholds for updating CIP and PIR, the capacity of the physical IF, and the maximum number of users that can be accommodated per physical IF (S11).

[0051] Thereafter, the first acquisition unit 142 acquires time-series data (network monitoring information) from the DB (S12). Then, the second acquisition unit 143 acquires network monitoring information during times of traffic congestion from the acquired network monitoring information.

[0052] Thereafter, the calculation unit 144 calculates the average bandwidth of high-priority traffic during traffic congestion from the NW monitoring information during traffic congestion acquired by the second acquisition unit 143, and calculates the average number of simultaneously connected users during traffic congestion (S13).

[0053] Thereafter, the calculation unit 144 calculates the CIR using the above-mentioned formula (1) using the average bandwidth of high-priority traffic during traffic congestion and the average number of simultaneously connected users calculated in S13, and calculates the PIR using the above-mentioned formula (2) (S14).

[0054] Thereafter, the determination unit 145 determines whether the difference between the CIR and PIR calculated in S14 and the previous CIR and PIR settings is equal to or greater than a threshold (S15: Difference from previous settings is equal to or greater than a threshold?). If the determination unit 145 determines that the difference between the previous CIR and PIR settings for at least one of the CIR and PIR calculated in S14 is equal to or greater than a threshold (Yes in S15), the process proceeds to S16. The output processing unit 146 then converts the CIR and PIR calculated in S14 into a command for the edge router and submits the setting to the edge router 20 (S16). Thereafter, the process returns to S12.

[0055] On the other hand, if the determining unit 145 determines that the difference between the CIR and PIR calculated in S14 and the previous CIR and PIR settings is less than the threshold (No in S15), the process returns to S12.

[0056] By executing the above process, the NW control device 10 can set an appropriate CIR and PIR to the edge router 20 in consideration of observed data on the traffic volume of the physical IF.

[0057] [Other Embodiments] In the above-described embodiment, when calculating the CIR, the calculation unit 144 may calculate the CIR by adding the standard deviation to the average bandwidth used by high-priority traffic during traffic congestion, as shown in the following formula (3).

[0058] CIR = (physical interface capacity - (average + standard deviation of bandwidth used by high-priority traffic during traffic congestion)) / maximum number of users accommodated...Equation (3)

[0059] Furthermore, when calculating the PIR, the calculation unit 144 may calculate the PIR using a value obtained by adding the standard deviation to the average bandwidth used by high-priority traffic when traffic is congested, and a value obtained by adding the standard deviation to the average number of simultaneously connected users when traffic is congested, as shown in the following equation (4).

[0060] PIR = (capacity of physical interface - (average + standard deviation of bandwidth used by high-priority traffic during traffic congestion)) / (average + standard deviation of number of simultaneously connected users during traffic congestion)...Equation (4)

[0061] In this way, when calculating the CIR and PIR, the calculation unit 144 uses values ​​obtained by adding the standard deviation to the average of the bandwidth used and the number of simultaneously connected users of high-priority traffic when traffic is congested, thereby making it possible to set stricter values ​​for the CIR and PIR to be set in the edge router 20. As a result, when the edge router 20 colors the packets of each user's traffic using the trTCM that uses the above-mentioned CIR and PIR and performs QoS control, it is possible to reduce the probability that packets colored green by the trTCM (packets with the highest priority) will be discarded.

[0062] An example of the processing procedure executed by the NW control device 10 will be described with reference to Fig. 8. Since S21 and S22 in Fig. 8 are similar to S11 and S12 in Fig. 7, their description will be omitted and the description will start from S23 in Fig. 8.

[0063] The calculation unit 144 calculates the average and standard deviation of the bandwidth of high-priority traffic during traffic congestion from the NW monitoring information during traffic congestion acquired by the second acquisition unit 143, and calculates the average and standard deviation of the number of simultaneously connected users during traffic congestion (S23).

[0064] Thereafter, the calculation unit 144 calculates the CIR using the average + standard deviation of the bandwidth of high-priority traffic and the average + standard deviation of the number of simultaneously connected users during traffic congestion calculated in S23, using the above-mentioned formula (3), and calculates the PIR using the above-mentioned formula (4) (S24).

[0065] The subsequent processes of S25 and S26 are the same as the processes of S15 and S16 in FIG. 7, and therefore will not be described here.

[0066] By having the NW control device 10 execute the above process, it is possible to set an appropriate CIR and PIR in the edge router 20 in consideration of observed data on the traffic volume of the physical IF.

[0067] When calculating the CIR and PIR, the calculation unit 144 may use, for example, a value obtained by adding two times the standard deviation (σ) (2σ) or three times the standard deviation (σ) (3σ) to the average bandwidth used and number of simultaneously connected users of high-priority traffic during times of traffic congestion.

[0068] Furthermore, although the case where the output processing unit 146 sets the CIR and PIR of the trTCM to the edge router 20 has been described, the present invention is not limited to this. For example, the output processing unit 146 may present the CIR and PIR calculated by the calculation unit 144 to a network operator or the like via the input / output unit 11. This allows the network operator or the like to be provided with information to determine the CIR and PIR to be set to the edge router 20.

[0069] Furthermore, the NW control device 10 calculates the CIR and PIR based on observed data of traffic at the physical IF and sets them in the edge router 20, thereby improving fairness among the traffic of each user in the BE traffic.

[0070] 9, the CIR and PIR values ​​for C2 are values ​​set by the NW control device 10 based on observed traffic data of the physical IF. On the other hand, the CIR and PIR values ​​for C1 are values ​​that are on the safer side than those for C2 (lower than C2).

[0071] Packets are colored by the CIR and PIR shown in C1 and C2 above, and the total amount of inflow traffic and the ratio of packets of each color when packets are discarded by WRED are indicated by reference numeral 101 in Fig. 10. The amount of packets of each color discarded by WRED is indicated by reference numeral 102.

[0072] For example, as shown by reference numeral 102 in Figure 10, Red packets are discarded in roughly equal numbers in both cases C1 and C2. However, as shown by reference numeral 102, C1 has more Red packets than C2 to begin with. In other words, there is a possibility that a single user's traffic contains a large number of Red packets, and the total amount of discarded Red packets is made up entirely of Red packets from one or more specific users. In other words, there is a possibility that fairness in the amount of traffic among each user is not being ensured.

[0073] On the other hand, for example, as shown by reference numeral 1101 in FIG. 11, if the CIR and PIR values ​​are appropriate, most of the Red packets in each user's traffic will be subject to discarding, and as a result, the number of packets discarded will be approximately the same for each user.

[0074] However, for example, if the CIR and PIR values ​​are too strict (too low), as shown by reference numeral 1102, there will be more Red packets than necessary. As a result, although the total number of discarded packets should be the same as in the case of reference numeral 1101, there is a possibility that the discarded packets will be biased towards packets from a particular user's traffic.

[0075] Also, although not shown here, if the CIR and PIR values ​​are too high (or too loose), packets of the same color may flow into the physical interface when the traffic bandwidth of each user is high. In this case, too, there is a possibility that packets of a particular user's traffic will be discarded disproportionately.

[0076] On the other hand, the NW control device 10 calculates the CIR and PIR based on observed data of traffic on the physical IF and sets appropriate values ​​for the CIR and PIR, thereby ensuring fairness in the traffic volume of each user.

[0077] [System Configuration, etc.] The components of each unit shown in the figure are conceptual functional units and do not necessarily have to be physically configured as shown. In other words, the specific form of distribution and integration of each device is not limited to that shown, and all or part of them can be functionally or physically distributed and integrated in any unit depending on various loads, usage conditions, etc. Furthermore, all or any part of the processing functions performed by each device can be realized by a CPU and a program executed by the CPU, or can be realized as hardware using wired logic.

[0078] Furthermore, among the processes described in the above embodiments, all or part of the processes described as being performed automatically can be performed manually, or all or part of the processes described as being performed manually can be performed automatically using a known method.In addition, the information including the processing procedures, control procedures, specific names, various data and parameters shown in the above documents and drawings can be changed as desired unless otherwise specified.

[0079] [Program] The NW control device 10 can be implemented by installing a program (NW control program) as package software or online software on a desired computer. For example, by executing the program on an information processing device, the information processing device can function as the NW control device 10. The information processing device referred to here includes mobile communication terminals such as smartphones, mobile phones, and PHS (Personal Handyphone Systems), as well as terminals such as PDAs (Personal Digital Assistants).

[0080] 12 is a diagram showing an example of a computer that executes a network control program. The computer 1000 includes, for example, a memory 1010 and a CPU 1020. The computer 1000 also includes a hard disk drive interface 1030, a disk drive interface 1040, a serial port interface 1050, a video adapter 1060, and a network interface 1070. These components are connected by a bus 1080.

[0081] The memory 1010 includes a read-only memory (ROM) 1011 and a random access memory (RAM) 1012. The ROM 1011 stores a boot program such as a basic input / output system (BIOS). The hard disk drive interface 1030 is connected to a hard disk drive 1090. The disk drive interface 1040 is connected to a disk drive 1100. A removable storage medium such as a magnetic disk or optical disk is inserted into the disk drive 1100. The serial port interface 1050 is connected to a mouse 1110 and a keyboard 1120, for example. The video adapter 1060 is connected to a display 1130, for example.

[0082] The hard disk drive 1090 stores, for example, an OS 1091, an application program 1092, a program module 1093, and program data 1094. That is, the programs that define the processes executed by the NW control device 10 are implemented as program modules 1093 in which computer-executable code is written. The program modules 1093 are stored, for example, in the hard disk drive 1090. For example, the program modules 1093 for executing processes similar to those of the functional configuration of the NW control device 10 are stored in the hard disk drive 1090. The hard disk drive 1090 may be replaced by an SSD (Solid State Drive).

[0083] Data used in the processing of the above-described embodiment is stored as program data 1094, for example, in the memory 1010 or the hard disk drive 1090. The CPU 1020 then reads the program module 1093 or the program data 1094 stored in the memory 1010 or the hard disk drive 1090 into the RAM 1012 as necessary and executes them.

[0084] The program module 1093 and program data 1094 may not necessarily be stored in the hard disk drive 1090, but may also be stored in a removable storage medium and read by the CPU 1020 via the disk drive 1100 or the like. Alternatively, the program module 1093 and program data 1094 may be stored in another computer connected via a network (such as a local area network (LAN) or a wide area network (WAN)). The program module 1093 and program data 1094 may then be read by the CPU 1020 from the other computer via the network interface 1070.

[0085] REFERENCE SIGNS LIST 10 NW control device 11 Input / output unit 12 Communication unit 13 Storage unit 14 Control unit 141 Information input reception unit 142 First acquisition unit 143 Second acquisition unit 144 Calculation unit 145 Determination unit 146 Output processing unit

Claims

1. A network control device comprising: a first acquisition unit that acquires time series data on the bandwidth used in a physical interface accommodating traffic of multiple users and the number of simultaneously connected users; a second acquisition unit that acquires, based on the acquired time series data, the bandwidth used in the physical interface, the bandwidth used by traffic with a priority equal to or higher than a predetermined value, and the number of simultaneously connected users during a time period when the bandwidth usage rate of the physical interface is equal to or higher than a predetermined value; a calculation unit that uses a trTCM (two rate three color marker) to color packets of the traffic on a user traffic basis, and calculates a CIR (Committed Information Rate) and a PIR (Peak Information Rate) to be used in the trTCM in an edge router that performs QoS control, based on the bandwidth used in the physical interface of traffic with a priority equal to or higher than a predetermined value during the time period, the number of users assigned to the physical interface, and the number of simultaneously connected users; and an output processing unit that outputs the calculated CIR and PIR.

2. The network control device according to claim 1, characterized in that the CIR is a bandwidth obtained by subtracting the average bandwidth used by traffic whose priority is equal to or higher than a predetermined value during said time period from the available bandwidth of the physical interface, and the PIR is a bandwidth obtained by subtracting the average bandwidth used by traffic whose priority is equal to or higher than a predetermined value during said time period from the available bandwidth of the physical interface, and the PIR is a bandwidth obtained by dividing the average number of users simultaneously connected to the physical interface during said time period.

3. A network control method executed by a network control device, comprising the steps of: acquiring time series data on the bandwidth used in a physical interface accommodating traffic of multiple users and the number of simultaneously connected users; acquiring, based on the acquired time series data, the bandwidth used in the physical interface, the bandwidth used by traffic with a priority of a predetermined value or higher, and the number of simultaneously connected users during a time period when the bandwidth usage rate of the physical interface is equal to or higher than a predetermined value; coloring the packets of the traffic using a two rate three color marker (trTCM) on a user traffic basis, and calculating a Committed Information Rate (CIR) and Peak Information Rate (PIR) to be used in the trTCM in an edge router that performs QoS control, based on the bandwidth used in the physical interface of traffic with a priority of a predetermined value or higher during the time period, the number of users assigned to the physical interface, and the number of simultaneously connected users; and outputting the calculated CIR and PIR.

4. A network control program for causing a computer to execute the steps of: acquiring time series data on the bandwidth used in a physical interface accommodating traffic from multiple users and the number of simultaneously connected users; acquiring, based on the acquired time series data, the bandwidth used in the physical interface, the bandwidth used by traffic with a priority of a predetermined value or higher, and the number of simultaneously connected users during a time period when the bandwidth usage rate of the physical interface is equal to or higher than a predetermined value; coloring the packets of the traffic using a two rate three color marker (trTCM) on a user traffic basis, and calculating a Committed Information Rate (CIR) and a Peak Information Rate (PIR) to be used in the trTCM in an edge router that performs QoS control, based on the bandwidth used in the physical interface for traffic with a priority of a predetermined value or higher during the time period, the number of users assigned to the physical interface, and the number of simultaneously connected users; and outputting the calculated CIR and PIR.

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