JP2012028878A - Data recording system, data recording device, management device, and communication volume control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a data recording system, a data recording device, a management device, and a communication volume control method which perform communication at a communication speed at which a transmission packet is never discarded.SOLUTION: The data recording system having a data transmission device 8 and a data recording device 17 networked with this acquires, using an SNMP management function mounted on the data recording device 17 or a device 20 on the network, packet discard information in communication between the data transmission device and the data recording device, and controls the volume of the data communication between the data transmission device and the data recording device based on the packet discard information.

Description

  The present invention relates to a data recording system that controls the amount of communication between devices on a network, and in particular, a data recording system that controls the amount of communication based on “discarded number of transmitted packets” information acquired using an SNMP management function. The present invention relates to a data recording device, a management device, and a communication amount control method.

In recent years, for example, an image recording system such as an image monitoring system that includes a monitoring camera, an image recording device, a network switch, and an image display device and monitors image data and records image data in the image recording device has been operated.
Patent Document 1 discloses an image distribution system having a function of accumulating image signals on a network, and particularly discloses a function of displaying an image distribution status.

JP 2008-148347 A

  However, in the above-described image recording system using a network, when a communication with a certain amount or more is performed, for example, a transmission packet may be discarded in a network switch unit responsible for data transfer. Also, the above-described Patent Document 1 does not describe how to deal with the discard of the transmission packet.

  An object of the present invention is to provide an image recording system, an image recording apparatus, a management apparatus, and a communication amount control method that perform communication at a communication speed at which a transmission packet is not discarded.

  In order to solve the above problems, a data recording system of the present invention is a data recording system including a data transmission device and a data recording device connected to the data transmission device via a network, the data recording device or the data recording device Using an SNMP management function installed in a device on the network, packet discard information in communication between the data sending device and the data recording device is acquired, and the data sending device and the data are acquired based on the packet discard information. Controlling the amount of communication with the recording apparatus.

  The data recording system further includes a network switch to which the data transmission device is connected and which converges and outputs data input from the data transmission device, and the data recording device or the device on the network includes A packet discard information of the network switch is acquired using an SNMP management function, and a transmission data amount of the data transmission device is controlled based on the packet discard information.

  In the data recording system, the data recording apparatus or the apparatus on the network controls until the acquired packet discard information becomes 0 or a predetermined value or less.

  Further, in the data recording system, the data recording device or the device on the network increases the transmission data amount of the data transmission device by a predetermined value when the acquired packet discard information is 0 for a predetermined period, When the packet discard information exceeds 0, the immediately previous transmission data amount is controlled as the transmission data amount of the data transmission device.

  Further, in the data recording system, the data recording device or the device on the network acquires the input data amount and output data amount information of the network switch, and the network switch has the output data amount smaller than the input data amount as the packet. It is characterized by being subject to acquisition of discard information

  In order to solve the above problems, a data recording apparatus according to the present invention is a data recording apparatus that communicates with a data transmission apparatus via a network, has an SNMP management function, and uses the SNMP management function. Packet discard information in communication with a data device is acquired, and the amount of communication with the data transmission device is controlled based on the packet discard information.

  In order to solve the above problem, the management device of the present invention is a management device that manages the amount of communication on the network between the data transmission device and the data recording device, and is provided on the network, Packet discard information in communication between the data transmission device and the data recording device is acquired using an SNMP management function, and the communication amount between the data transmission device and the data recording device is determined based on the packet discard information. It is characterized by controlling.

  In order to solve the above problem, a communication data amount control method of the present invention is a communication amount control method for controlling a communication amount on a network between a data transmission device and a data recording device, and the data transmission device Packet discard information in communication between the data recording apparatus and the data recording apparatus using an SNMP management function, and based on the acquired packet discard information, the amount of communication data between the data sending apparatus and the data recording apparatus It is characterized by controlling.

  Using the SNMP management function used in the communication network, obtain “discarded transmission packet number” information in communication between devices, adjust the communication amount step by step based on this information, and this “discarded transmission packet” By bringing “number” close to zero, communication with the optimum amount of communication is automatically realized without manual adjustment by the user.

1 is a block diagram showing an example of the configuration of an image recording system according to an embodiment of the present invention. The block diagram which shows the structure of the network switch which concerns on one Embodiment of this invention. Explanatory drawing which shows an example of the data transmission timing in the network switch which concerns on one Embodiment of this invention. Explanatory drawing which shows an example of the data transmission timing in case the transmission packet in the network switch which concerns on one Embodiment of this invention is discarded. 6 is a flowchart showing an example of a traffic shaping control process in the image recording system according to the embodiment of the present invention. FIG. 4 is an explanatory diagram illustrating a state in which a transmission packet is prevented from being discarded by traffic shaping control in the network management table and the traffic shaping control management table held in the recording apparatus of the image recording system according to the embodiment of the present invention. Similarly, in the network management table and the traffic shaping control management table held in the recording apparatus of the image recording system according to the embodiment of the present invention shown in FIG. 6, the transmission packet is discarded by the stepwise traffic shaping control. Explanatory drawing which shows a mode that it avoided. Explanatory drawing which shows a mode that the transmission packet was avoided by traffic shaping control in the image recording system which concerns on one Embodiment of this invention. 7 is a flowchart showing an example of a traffic shaping control process when automatically selecting a network switch to be monitored in traffic shaping control according to another embodiment of the present invention. The block diagram which shows an example of a structure of the image recording system which concerns on other one Embodiment of this invention. Description showing a state in which a transmission packet is avoided from being discarded by traffic shaping control in a network management table and a traffic shaping control management table held in a management apparatus of an image recording system according to another embodiment of the present invention. Figure. 9 is a flowchart showing an example of a traffic shaping control process in an image recording system according to another embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram illustrating an example of a configuration of an image recording system according to an embodiment of the present invention. FIG. 2 is a block diagram illustrating a configuration of a network switch of the image recording system according to an embodiment of the present invention. 3 is an explanatory diagram showing an example of data transmission timing in the network switch of the image recording system according to the embodiment of the present invention. FIG. 4 is a diagram showing transmission packets in the network switch of the image recording system according to the embodiment of the present invention. It is explanatory drawing which shows an example of the data transmission timing in the case of discarding.

  As shown in FIG. 1, the image recording system according to an embodiment of the present invention has, as an example, an edge switch 1 and a plurality of cameras 8, 9, 10 connected thereto in the first monitoring area. In the second monitoring area, the edge switch 2 and a plurality of cameras 11, 12, 13 connected thereto are provided. In the third monitoring area, the edge switch 3 and a plurality of cameras connected thereto are provided. Cameras 14, 15 and 16 are provided.

  Furthermore, this image recording system has an edge switch 6 and a plurality of recording devices 17, 18, 19 and a management device 20 connected thereto in the recording area. Further, this image recording system has an edge switch 7 and a plurality of display devices 21, 22, and 23 connected thereto in the monitor area. These monitoring area, recording area, and monitoring area are connected via a center switch 4 and a center switch 5.

  Further, at least the edge switch 1, the center switch 4, and the center switch 5 respectively have SNMP (Simple Network Management Protocol) processing units 64, 65, and 66, respectively. In addition, at least the recording device 17 has an SNMP management unit 67. However, the present invention is not limited to this, and the edge switches 2, 3, 7 may also have SNMP processing units, and the recording devices 18, 19 may also have SNMP management units.

  This SNMP management unit has an SNMP manager (NMS: Network Management Station) function, and grasps the status of network devices in order to control network traffic and maintain stable communication quality. The SNMP processing unit has an SNMP agent function, and holds management information called MIB (Management Information Base). In this MIB, information related to the hardware interface possessed by the device is managed in a portion called an interface group. As one piece of the management information, there is information indicating “ifOutDiscard: number of discarded transmission packets”.

  In the recording area recording devices 17, 18, and 19, cameras 8,... 16 connected to the monitoring area are registered, and connected to the corresponding cameras via a network, and image data is recorded at a pre-registered frame rate. Is acquired and an image is recorded. The management device 20 manages information such as the IP addresses of the cameras 8,..., 16 and the recording devices 17, 18, and 19 and the display device of the entire system in a database and performs fault monitoring. Here, the recording device 17 records the images of the cameras 8 to 10, the recording device 18 records the images of the cameras 11 to 13, and the recording device 19 records the images of the cameras 14 to 16.

  The display devices 21, 22 and 23 in the monitor area are connected to a target camera via a network, acquire a live image, and display the image on the display unit of the own device. Also, when confirming the recorded image of an arbitrary camera, specify “camera name etc.”, “recorded image date / time”, “recorded image playback control”, etc., and connect to the target recording device via the network. And the recorded image is displayed on the display unit of the own device.

  Next, the internal configuration of the edge switches 1, 2, 3 and the center switch 4 described above will be described with reference to FIGS. In FIG. 2A, it is assumed that the camera 24... Camera 27 corresponding to the above-described cameras 8... 16 is connected to the physical ports 28 to 31 of the edge switches 1, 2 and 3. The physical port 32 and the physical port 33 are used as uplink ports to the center switch 4 which is an adjacent network switch. Here, the physical ports 28 to 31 are 24 ports in total, and the physical ports 32 and 33 are 2 ports in total. Packet data input / output from each physical port is exchanged via the input / output buffers 34 to 39 and the backplane 40. Now, if the transfer rate of the physical ports 32 and 33 is defined as 1000 Mbps and the transfer rate of the physical ports 28 to 31 is defined as 100 Mbps, the backplane is required to have a transmission rate of at least 8.8 Gbps. Therefore, the transmission rate for the backplane 40 in the normal network switch has the capability of enabling transfer at a transfer rate higher than the total transfer rate of the data amount input / output from the physical port.

  Further, in FIG. 2B, the above-mentioned edge switches 1,..., 3 (and other edge switches may be connected) are connected to the physical ports 28 ′ to 31 ′ of the center switch 4. Assume that the port is connected. Here, the total number of physical ports 28 ′ to 31 ′ is 24 ports. Packet data input / output from each physical port is exchanged via the input / output buffers 34 ′ to 37 ′ and the backplane 40 ′. If the transfer rate of the physical ports 28 'to 31' is defined as 1000 Mbps, the backplane is required to have a transmission rate of at least 48 Gbps. Therefore, the transmission rate for the backplane 40 ′ in the normal network switch has the capability of enabling transfer at a transfer rate higher than the total transfer rate of the data amount input from the physical port.

Here, in FIG. 3, when the data from the cameras connected to the physical ports 28 to 31 is output at an arbitrary timing, the transmission packet is transferred from the uplink of the physical port 33 to the adjacent network switch. Indicates the state of the number. When the packet transfer timings of data input from the physical ports 28 to 31 are different, the packet data output from the uplink of the physical port 33 because the number of packets has not reached the threshold at which the number of transmitted packets is discarded. Are transferred without being destroyed.
The same applies to the center switch 4.

  On the other hand, FIG. 4 shows the number of packets transferred from the uplink of the physical port 33 to the adjacent network switch when data from the cameras connected to the physical ports 28 to 31 are output at the same timing. Indicates the state. When the packet transfer timings of data input from the physical ports 28 to 31 overlap, the packet data output from the uplink of the physical port 33 is discarded if it exceeds the threshold of the number of packets that can be transmitted. It becomes. This phenomenon is because the transmission rate of the backplane 40 is larger than the transfer rate obtained by adding up the amount of data inputted / outputted from each physical port. It will occur as a difference. For this reason, input / output buffers 34 to 39 are provided for each physical port, and packet data flowing from the backplane 40 in a burst (large amount) by this buffer is output from the physical port while adjusting the output timing. I'm in charge.

  However, there is a physical size limit on the input / output buffer, and if a large number of packets are input to the input / output buffer, the amount of packets that exceed the buffer limit will be discarded. . When such a transmission packet is discarded, the discarded packet is retransmitted, the substantial communication speed is reduced, and further network traffic is generated.

  Next, traffic control in the image recording system according to the embodiment of the present invention will be described in detail below using the flowchart of FIG. 5, the management table of FIGS. 6 and 7, and the data transmission timing explanatory diagram of FIG. As described below, the traffic control in the image recording system according to the embodiment of the present invention is based on the traffic shaping value according to the “number of discarded transmission packets” information acquired by the SNMP management unit 67. Is controlled step by step. FIGS. 6A, 6B, 7C, and 7D and 7E sequentially show the results of a series of stepwise control of one traffic process, and FIG. 6C shows (d) ).

  Here, it is assumed that the recording device 17 holds a network switch management table as shown in FIG. The purpose of this management table is “the number of discarded transmission packets” at the corresponding physical port (hardware interface number) in the network switch of the IP address shown in the management table by the SNMP management unit 67 installed in the recording device 17. Is to manage. In this table, the “IP address” of the edge switch 1 (SW1 in the table) and the uplink physical port “hardware interface number: 25”, as well as the “IP address” of the center switch 4 (SW4 in the table) and It is assumed that the uplink physical port “hardware interface number: 25”, the “IP address” of the center switch 5 (SW5 in the table), the uplink physical port “hardware interface number: 1”, and the like are registered. Alternatively, the network switch information may be added or updated by detecting the topology or device on the network.

  At the same time, the recording device 17 holds a traffic shaping control management table for the network camera as shown in FIG. The purpose of this management table is to perform traffic shaping on the data sent from the camera by registering “recording frame rate” and “bit rate value depending on image quality and frame rate” determined for each camera. It is.

  First, the recording device 17 requests an image from the network camera, the network camera transfers image data to the recording device 17, and the recording device 17 receives the image data and records it at the set frame rate (S1). ). The SNMP management unit 67 acquires the “number of discarded packets” information from the MIB held by the SNMP processing unit of each network switch by the SNMP command, and updates the network switch management table (S2). The SNMP management unit 67 determines a traffic shaping value for the camera based on the acquired “number of discarded packets” information, and updates the traffic shaping control management table (S3). Here, based on the “number of discarded packets” information, for example, if the “number of discarded packets” is large, the reduction width of the traffic shaping value is large, and if it is small, the reduction width is small. However, at this time, the traffic shaping value is always the limit value (lower limit) of the “bit rate value depending on image quality and frame rate” for the network camera. These conditions are the same when the traffic shaping value is set in the subsequent steps. The camera transfers the data using the traffic shaping value determined in S3 as the transfer rate, acquires the “number of discarded packets” information again, and updates the network switch management table (S4).

  Next, it is determined whether or not the “number of discarded packets” acquired in S4 is “0”. If it is not “0” (NO), the process of S3 is executed again, and the “number of discarded packets” is determined. Repeat until “0”. On the other hand, if the “number of discarded packets” is “0” (YES), the camera transfers data based on the determined traffic shaping value, and periodically acquires the “number of discarded packets” information. The network switch management table is updated (S6).

  Here, for efficient data transfer, it is further determined whether the “number of discarded packets” acquired in S6 continues for “0” for a predetermined period (S7), and “0” continues. (YES), it is determined that there is still a margin in the transfer rate, and the traffic shaping value for the camera is slightly increased to transfer the data, and the “number of discarded packets” information is acquired (S8), and is repeated until it is no longer “0”. . At this time, the range of the traffic shaping value to be increased is an arbitrary value. On the other hand, if the “number of discarded packets” is no longer “0” (NO), the previous value is determined to be the optimum value of the traffic shaping value (transfer rate) for the camera, and the traffic shaping control management table is updated. The camera transfers data with the most recent traffic shaping value as the optimum transfer rate.

  Here, how the traffic shaping value is determined according to the number of discarded packets will be described. For example, in FIG. 5B, when the number of discarded transmission packets of SW (switch) 1 is “118”, traffic shaping is performed with the traffic shaping value as “4800 kbps”. As a result, as shown in (c), the number of discarded transmission packets of SW1 is “42” and does not become “0”. Therefore, the traffic shaping value corresponding to this “42” is −2000. Traffic shaping is performed as “2800 kbps”. As a result, as shown in (d), the number of transmission packets discarded by SW1 is “9” and does not become “0”. Further, the traffic shaping value corresponding to this “9” is set to −300. Traffic shaping is performed as “2500 kbps”. As a result, as shown in (e), the number of discarded transmission packets of SW1 is “0”, and it is determined that all the transmission packets have been transmitted. Thereafter, the data is transferred at a transfer rate of 2500 kbps.

  Here, the switch 1 has been described as an example, but the SNMP processing unit is also provided in the switch 2 and the switch 3, and at the same time, the “number of discarded transmission packets” is acquired and connected to each switch. It is desirable that traffic shaping is performed on the cameras, and it is possible to operate the system so as to control network traffic and maintain stable communication quality in the entire network monitoring system.

  In addition, although the determination in S5 and S7 is “0” here, it is also possible to use a value determined by the user or a value derived from traffic information as a threshold value, and whether or not it is a predetermined threshold value or less.

  Also in the center switch 4, a form in which traffic shaping is similarly performed on data input from the connected edge switches 1 to 3 is also conceivable.

  As shown in FIG. 8, these network traffic control effects apply traffic shaping to data sent from cameras connected to physical ports 28 to 31 of edge switch 1 (SW1 in the table). It can be understood by the state of the number of packets in the case of. In other words, the packet data output from the uplink of the physical port 33 by the network traffic control (traffic shaping process) has a threshold value for the number of packets that can be transmitted even when the data from the camera is output at the same timing. Without exceeding, stable network communication can be realized with an optimal communication amount.

  Accordingly, it is possible to provide an image recording system, an image recording apparatus, a management apparatus, and a communication amount control method with an optimal transfer rate that does not cause a transmission packet to be discarded.

  As another embodiment of the present invention, how a network switch to be monitored is selected will be described in detail with reference to FIG. FIG. 9 is a flowchart illustrating an example of a traffic shaping control process when a network switch to be monitored is automatically selected. This embodiment differs from the first embodiment described with reference to the flowchart of FIG. 5 in S12 and S13, and the other points are the same and will be omitted as much as possible.

  The recording device 17 requests an image from the network camera and receives data (S11: corresponding to S1 in FIG. 5). Next, the SNMP management unit 67 measures the input data amount on the input side and the output data amount on the uplink port side of each switch 1, 2, 3, 4, 5, 6, 7, etc., and determines the relationship. Then, the network switch management table and the traffic shaping control management table are updated with the network switch whose input data amount is larger than the output data amount being monitored (S12). Here, as to which switch is to be a monitoring target switch, the SNMP management unit 67 may initially measure the amount of data and add it. However, all the switch information is acquired in advance. When the input data amount is less than or equal to the output data amount, it may be excluded from the monitoring target. When the network switch to be monitored is determined in S12, the SNMP management unit 67 acquires the “number of discarded packets” information from the MIB held by the SNMP processing unit of the network switch to be monitored by the SNMP command (S13). ). Thereafter, the same processing as that of the first embodiment described in FIG. 5 is performed (S14 to S20: corresponding to S3 to 9 in FIG. 5).

  According to the present embodiment, since only the network switch to be monitored can be monitored, less information is managed, and the network can be managed more simply and easily.

  The case where traffic shaping is performed by the SNMP management unit 67 installed in the recording devices 17, 18, and 19 has been described above. However, as shown in FIG. 10, an SNMP management unit 70 is installed in the management device 20, holds a network switch management table as shown in FIG. Even if an operation for performing traffic shaping is adopted, similarly, it becomes possible to perform smooth network communication by avoiding discard of a transmission packet. The traffic shaping control in this case will be described below.

  The edge switch 1, edge switch 2, edge switch 3, center switch 4, and center switch 5 have SNMP (Simple Network Management Protocol) processing units 64, 65, and 66, respectively. The management device 20 has an SNMP management unit 70. The SNMP management unit 70 of the management apparatus 20 has the network switch management table shown in FIG. 11, manages information such as the IP address, hardware interface number, and the number of discarded transmission packets of each network switch. A state in which the management apparatus collectively manages the traffic shaping control management table of the apparatus will be described.

  The SNMP management unit 70 of the management device 20 has a network switch management table for managing each network switch on the network shown in FIG. 11, and the recording devices 17 to 19 are networks managed by each recording device. Each has a traffic shaping control management table for the camera.

  The SNMP management unit 70 of the management apparatus 20 acquires “discarded packet number” information from the MIB held by the SNMP processing unit of each network switch by the SNMP command, and “discarded packet number” in the network switch management table. Information is updated (S22). The SNMP management unit 70 determines the traffic shaping value for the network camera managed by the recording devices 17 to 19 according to the “number of discarded transmission packets” information of each network switch, and updates each traffic shaping control management table (S23). The recording devices 17 to 19 control each network camera to transfer data with the determined and updated traffic shaping values (S24).

  Then, the SNMP management unit 70 of the management apparatus 20 acquires the “number of discarded packets” information of each network switch again, updates the network switch management table, and determines whether or not the number of discarded transmission packets is “0”. (S25). If the “number of discarded packets” is not “0” (NO), the process of S23 is performed again, and the process is repeated until the “number of discarded packets” becomes “0”. On the other hand, when the “number of discarded packets” is “0” (YES), the recording devices 17 to 19 transfer data to the respective network cameras with the determined and updated traffic shaping values. The network switch management table is updated by periodically acquiring the “number of discarded packets” information (S26).

  Here, for efficient data transfer, it is further determined whether or not the “number of discarded packets” acquired in S26 continues for “0” for a predetermined period (S27), and “0” continues. (YES), the SNMP management unit 70 of the management device 20 determines that there is still a margin in the transfer rate, slightly increases the traffic shaping value for each camera, updates the traffic shaping management tables of the recording devices 17 to 19 respectively, and records them. The devices 17 to 19 control each network camera to transfer data with the determined and updated traffic shaping values, and acquire the “number of discarded packets” information again (S28). Repeat until “number of packets received” is no longer “0”. At this time, the range for increasing the traffic shaping value is an arbitrary value. On the other hand, when the “number of discarded packets” is no longer “0” (NO), the immediately preceding traffic shaping value is determined to be the optimum value of the traffic shaping value (transfer rate) for each camera, and the SNMP management of the management apparatus 20 is performed. The unit 70 updates the traffic shaping control management tables of the recording devices 17 to 19, and the recording devices 17 to 19 determine and update the respective traffic cameras with the most recent traffic shaping value as the optimum transfer rate. Control is performed so as to transfer data with the traffic shaping value thus set (S29).

  In the present embodiment, the configuration in which each recording device has the traffic shaping control management table has been described. However, the management device may collectively manage the traffic shaping control management table.

  In this case, the SNMP management unit 70 of the management apparatus 20 includes a network switch management table for managing each network switch on the network illustrated in FIG. 11 and a traffic shaping control management table for the network camera managed by each recording apparatus. This is achieved by changing the control subject of S23, S24, S26, S28, and S29 in the flowchart shown in FIG. 12 from the recording devices 17 to 19 to the management device 20.

  In this embodiment, it goes without saying that the network switches to be monitored may be limited as in the second embodiment.

  According to the embodiment described above, it is possible to perform the smooth network communication by avoiding the discard of the transmission packet as in the first and second embodiments, and further, the management device can collectively manage the table. This makes it possible to manage the network more easily and uniformly.

  A plurality of the various embodiments described above can be implemented at the same time. With these descriptions, those skilled in the art can realize the present invention, but various modifications of these embodiments can be conceived. It is easy for a person skilled in the art and can be applied to various embodiments without inventive ability. Therefore, the present invention covers a wide range consistent with the disclosed principle and novel features, and is not limited to the above-described embodiments.

  1, 2, 3 ... edge switch, 4, 5 ... center switch, 6, 7 ... edge switch, 8, 9, 10, 11, 12, 13, 14, 15, 16, 24, 25, 26, 27 ... network Camera, 28, 29, 30, 31 ... physical port, 32, 33 ... physical port (uplink), 34, 35, 36, 37, 38, 39 ... I / O buffer, 40 ... backplane, 64, 65, 66 , 68, 69... SNMP processing unit, 67, 70... SNMP management unit.

Claims (4)

A data recording system having a data transmission device and a data recording device connected to the data transmission device via a network,
Using the SNMP management function installed in the data recording device or the device on the network, obtains packet discard information in communication between the data sending device and the data recording device, and based on the packet discard information, A data recording system for controlling a communication amount between a data transmission device and the data recording device.   A data recording device that communicates with a data transmission device via a network, equipped with an SNMP management function, acquires packet discard information in communication with the data transmission device using the SNMP management function, and A data recording apparatus for controlling a communication amount with the data transmission apparatus based on packet discard information. A management device that manages the amount of communication on the network between the data transmission device and the data recording device,
By being provided on the network, packet discard information in communication between the data sending device and the data recording device is acquired using an SNMP management function, and the data sending device and the data are collected based on the packet discard information. A management device that controls the amount of communication with a data recording device. A communication amount control method for controlling a communication amount on a network between a data transmission device and a data recording device,
Packet discard information in communication between the data sending device and the data recording device is acquired using an SNMP management function,
A communication amount control method, comprising: controlling a communication amount between the data transmission device and the data recording device based on the acquired packet discard information.

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