WO2018056399A1

WO2018056399A1 - Congestion suppression device, congestion suppression method, and program

Info

Publication number: WO2018056399A1
Application number: PCT/JP2017/034297
Authority: WO
Inventors: 泰明住吉
Original assignee: 日本電気株式会社
Priority date: 2016-09-23
Filing date: 2017-09-22
Publication date: 2018-03-29

Abstract

The present invention comprises: a data specification unit that specifies, on the basis of identification information for a requesting device, delivery data transmitted from one or a plurality of delivery devices to the requesting device; and a suppression start determination unit that determines, on the basis of the results of a comparison made between the data volume of delivery data among the delivery data already transmitted to the requesting device but not acknowledged as having been received, and a suppression start threshold that is set in the reception buffer of a relay device provided along the communication path between a congestion suppression device and the requesting device within the communication path between the delivery device(s) and the requesting device, whether or not to start the suppression control for the transmission volume per unit time to the relay device.

Description

Congestion suppression device, congestion suppression method, and program

The present invention relates to a congestion suppression device, a congestion suppression method, and a program.

Patent Documents 1 and 2 are disclosed as techniques for managing the state of communication data in a communication network. Both Patent Document 1 and Patent Document 2 show techniques for controlling the amount of buffer in the relay apparatus.

International Publication No. 2006/006208 JP 2010-081438 A

By the way, when a requesting device for information such as a terminal acquires distribution information from a distribution device such as a server in recent years, the terminal establishes a session with a plurality of different distribution devices based on the acquisition of the distribution information at the same time. A large amount of data may be received from each of a plurality of different distribution apparatuses. For example, in recent years, a terminal such as a smartphone receives data distributed from a web page or a social networking service (SNS) server on which a large number of photos, videos, and the like are displayed. When a plurality of link destinations are described in such distribution data, large-capacity data of several hundred KB (kilobyte) to several MB (megabyte) such as photos and videos to be the link destinations is simultaneously and in parallel. There are many situations in which data is received from a plurality of devices with different distribution sources. In such a situation, for example, due to congestion such as buffer overflow in the relay device in the wireless section, the delay is increased and the staying time is extended, thereby leading to the determination of the communication timeout in the distribution device that distributes a large amount of data. As a result, a distribution device such as a plurality of different servers performs processing for retransmitting large-capacity data, and further, the degree of communication congestion is increased in a relay device such as a base station device located at the boundary between a wireless network and a wired network. It is a factor of.

Therefore, an object of the present invention is to provide a congestion suppression device, a congestion suppression method, and a program that can suppress the degree of congestion.

According to the first aspect of the present invention, the congestion suppressing device, based on the identification information of the requesting device, a data specifying unit for specifying distribution data transmitted from one or a plurality of distribution devices to the requesting device; Of the distribution data that has already been transmitted to the requesting device, the amount of distribution data that has not received reception confirmation from the requesting device, and the congestion suppression device and the request on the communication path between the distribution device and the requesting device Whether to start suppression control of the transmission amount per unit time to the relay device based on the comparison result with the suppression start threshold set in the reception buffer of the relay device provided on the communication path with the device A suppression start determination unit for determining.

According to the second aspect of the present invention, the congestion suppression method specifies distribution data transmitted from one or a plurality of distribution apparatuses to the request apparatus based on identification information of the request apparatus, and the request apparatus Of the distribution data that has not been received from the requesting device and the communication between the requesting device and the own device on the communication path between the distributing device and the requesting device It is determined whether or not to start suppression control of the transmission amount per unit time to the relay device based on a comparison result with a suppression start threshold set in a reception buffer of the relay device provided on the path.

According to the third aspect of the present invention, the program specifies distribution data to be transmitted from one or a plurality of distribution devices to the requesting device based on the identification information of the requesting device. Of the distribution data transmitted to the device, the amount of distribution data that has not received reception confirmation from the requesting device, and the own device and the requesting device on the communication path between the distribution device and the requesting device It is determined whether or not to start suppression control of the transmission amount per unit time to the relay device based on a comparison result with a suppression start threshold set in the reception buffer of the relay device provided on the communication path, Execute the process.

According to the present invention, the degree of congestion of the relay device between the distribution device and the request device can be suppressed.

1 is a first diagram illustrating a congestion suppression system including a congestion suppression device according to an embodiment of the present invention. It is a 2nd figure which shows the congestion suppression system containing the congestion suppression apparatus by one Embodiment of this invention. It is a figure which shows the image of the communication system without a congestion suppression apparatus. It is a functional block diagram of the congestion suppression apparatus by one Embodiment of this invention. It is a hardware block diagram of the congestion suppression apparatus by one Embodiment of this invention. It is a figure which shows the communication image of the congestion suppression system by one Embodiment of this invention. It is a 1st figure which shows the processing flow of the congestion suppression apparatus by one Embodiment of this invention. It is a 2nd figure which shows the processing flow of the congestion suppression apparatus by one Embodiment of this invention. It is a figure which shows the minimum structure of the congestion suppression apparatus by one Embodiment of this invention.

Hereinafter, a congestion suppressing apparatus according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a first diagram showing a congestion suppression system including a congestion suppression device according to the embodiment.
As shown in the figure, in the congestion suppression system, a distribution device 1, a request device 2, a relay device 3, and a congestion suppression device 10 are connected via a communication network. Specifically, the distribution device 1 and the requesting device 2 are connected to a first communication network such as the Internet network 20 via a second communication network 30 such as a wireless transmission path. A congestion suppression device 10 and a relay device 3 are provided on a relay path between the distribution device 1 and the requesting device 2. The congestion suppression device 10 receives distribution data from the distribution device 1 via the first communication network 20 and transfers it to the relay device 3. The relay device 3 transfers the distribution data received from the congestion suppression device 10 to the requesting device 2 via the second communication network 30. The first communication network 20 is a communication network having a wider bandwidth than the second communication network 30.

In the congestion control system as shown in FIG. 1, the requesting device 2 requests the distribution device 1 for distribution data. The distribution apparatus 1 transmits distribution data to the request apparatus 2 based on the request from the request apparatus 2. For example, this distribution data is web page data including a link element for accessing information such as photos and moving images distributed by a plurality of different distribution apparatuses 1. Upon receiving such distribution data, the requesting device 2 requests distribution of data indicated by the link element to a plurality of different distribution devices 1 based on the link element.

FIG. 2 is a second diagram showing the congestion suppression system including the congestion suppression apparatus according to the embodiment.
As described above, when the requesting device 2 accesses an access destination based on a link element for accessing information such as a photo and a moving image, a plurality of different distribution devices 1 transmit distribution data to the requesting device 2. . The requesting device 2 receives the distribution data of the access destination indicated by the link element from the plurality of different distribution devices 1 at the same timing. As shown in FIG. 2, when the requesting device 2 makes distribution requests to a plurality of distribution devices 1, the distribution data transmitted from the respective distribution devices 1 via the congestion suppression device 10 and the relay device 3 are different. The request device 2 is reached by the session.

FIG. 3 is a diagram illustrating an image of a communication system in which no congestion suppression device is present.
When a plurality of distribution devices 1 (distribution device group) as shown in FIG. 2 simultaneously transmit distribution data to the request device 2, the relay device 3 sends a large amount of data to the request device 2 in a short period of time. Must be transferred. As the number of the plurality of distribution devices 1 increases and the total amount of distribution data of the distribution device 1 increases, the distribution data exceeds the amount of received data per unit time that the reception buffer of the relay device 3 can tolerate. Sent. As a result, the relay device 3 cannot receive the distribution data per unit time transmitted from the distribution device 1 by the reception buffer within the unit time, and discards a part of the distribution data that could not be received. In the case where the congestion suppression device 10 does not exist, many such phenomena have occurred. The present invention suppresses such a congestion state.

FIG. 4 is a functional block diagram of the congestion suppression apparatus.
As illustrated in FIG. 4, the congestion suppression apparatus 10 includes functions of a relay control unit 11, a data specifying unit 12, a suppression start determination unit 13, and a suppression control unit 14 by executing a program after activation.
The relay control unit 11 performs control of other functional units and standard data relay control.
The data specifying unit 12 specifies distribution data transmitted from one or a plurality of distribution devices 1 to the requesting device 2 based on the identification information of the requesting device 2 included in the data to be transferred.
The suppression start determination unit 13 determines the amount of distribution data that has not been received from the requesting device 2 among the distribution data that has already been transmitted to the requesting device 2, and the suppression start threshold set in the reception buffer of the relay device 3. Based on the comparison result, it is determined whether or not to start suppression control of the transmission amount per unit time to the relay device 3.
After it is determined that the suppression control is started, the suppression control unit 14 calculates a transmission suppression amount per unit time in which the data amount of the reception buffer of the relay device 3 does not exceed the upper limit set in the reception buffer. Then, the suppression control unit 14 transmits distribution data received from one or a plurality of distribution apparatuses 1 to the relay apparatus 3 according to the calculated transmission suppression amount.

FIG. 5 is a hardware configuration diagram of the congestion suppression apparatus.
As shown in this figure, the congestion suppression apparatus 10 is a computer having hardware such as a CPU (Central Processing Unit) 51, a storage unit 52, and a communication unit 53. The storage unit 52 may be a ROM (Read Only Memory), a RAM (Random Access Memory), or the like. The communication unit 53 includes a reception buffer 15 and a transmission buffer 16.

FIG. 6 is a diagram showing a communication image of the congestion suppression system according to the present embodiment. As shown in FIG. 6, in the congestion suppression system, a distribution apparatus 1, a request apparatus 2, a relay apparatus 3, and a congestion suppression apparatus 10 are connected via a communication network.
FIG. 7 is a first diagram illustrating a processing flow of the congestion suppression apparatus.
FIG. 8 is a second diagram illustrating a processing flow of the congestion suppression apparatus.
Next, the processing flow of the congestion suppression apparatus 10 will be described in order according to FIGS.
As shown in FIG. 2, it is assumed that distribution data is transmitted from one or a plurality of distribution apparatuses 1 to the request apparatus 2 based on a distribution request from the request apparatus 2. The relay control unit 11 of the congestion suppression device 10 transfers the received distribution data to the relay device 3. In this transfer, the data specifying unit 12 specifies the identification information of the requesting device 2 included in the header of the distribution data (step S1). The identification information may be an IP (Internet Protocol) address or another network address. Based on this identification information, the data specifying unit 12 determines whether a plurality of pieces of distribution data are being transferred to the same requesting device 2.

The suppression start determination unit 13 determines whether a plurality of pieces of distribution data are transferred to the requesting device 2 based on the identification information of the requesting device 2 (step S2). When a plurality of pieces of distribution data are transferred to the same requesting device 2 (YES in step S2), the suppression start determination unit 13 specifies the identification data of the requesting device 2 serving as a distribution destination. Then, the subsequent suppression start determination process is performed. When a plurality of distribution data is not transferred to the same requesting device 2 (NO in step S2), the suppression start determination unit 13 determines to perform standard transfer processing (step S10) for the distribution data. To do.

In the subsequent suppression start determination process, the suppression start determination unit 13 determines whether the total data amount CL (Content Length) of the distribution data can be specified (step S3). Usually, the distribution apparatus 1 stores the total amount of distribution data in the distribution data header or the like and transmits the distribution data. When the distribution data distributed by the distribution apparatus 1 is streaming data or encrypted data, the total data amount of the distribution data may not be confirmed. When the total data amount CL of the distribution data cannot be specified (NO in step S3), the suppression start determination unit 13 proceeds to the process in step S5. On the other hand, when the total data amount CL of the distribution data can be specified (YES in step S3), the suppression start determination unit 13 sets the total data amount CL of the distribution data in the reception buffer 15 of the relay device 3. It is determined whether it is larger than the total data amount threshold value X (first suppression start threshold value (first threshold value)) (step S4). When the total data amount CL of the distribution data is larger than the total data amount threshold value X (YES in step S4), the suppression start determination unit 13 performs a subsequent suppression start determination process for the distribution data. On the other hand, when the total data amount CL of the distribution data is equal to or less than the total data amount threshold value X (NO in step S4), the suppression start determination unit 13 performs standard transfer processing (step S10) for the distribution data. decide.

In the subsequent suppression start determination process, the suppression start determination unit 13 calculates the sum SUM (CW) of the data amount indicated by the Congestion Window in each session of distribution data for the same requesting device 2. SUM (CW) corresponds to the current free capacity of the reception buffer of the relay device 3. The suppression start determination unit 13 determines whether the value of SUM (CW) is larger than the reception buffer threshold Y (second suppression start threshold (second threshold)) of the relay device 3 (step S5). The reception buffer threshold Y indicates the upper limit value of the reception buffer of the relay device 3, for example. When the value of SUM (CW) is larger than the reception buffer threshold Y of the relay device 3 (YES in step S5), the suppression start determination unit 13 performs subsequent suppression start determination processing on the distribution data. When the value of SUM (CW) is equal to or less than the reception buffer threshold Y of the relay device 3 (NO in step S5), the suppression start determination unit 13 determines to perform standard transfer processing (step S10) for the distribution data. To do.

In the subsequent suppression start determination process, the suppression start determination unit 13 calculates an average data transfer amount AVE (TP) per unit time of all distribution data sessions for the same requesting device 2. The suppression start determination unit 13 calculates an average data transfer amount per unit time for each session based on the data amount transmitted from the transmission buffer 16, averages the calculated data amount, and calculates the average data transfer amount AVE ( TP) is calculated. The suppression start determination unit 13 determines that the average data transfer amount AVE (TP) per unit time of all distribution data sessions for the same requesting device 2 is a preset average data transfer amount threshold value Z (third suppression start threshold value). It is determined whether it is larger than (third threshold)) (step S6). When the average data transfer amount AVE (TP) per unit time of all distribution data sessions for the same requesting device 2 is larger than the average data transfer amount threshold Z (YES in step S6), the suppression start determining unit 13 Subsequent suppression start determination processing is performed on the distribution data. On the other hand, when the average data transfer amount AVE (TP) per unit time of the session of all distribution data for the same requesting device 2 is equal to or less than the average data transfer amount threshold Z (NO in step S6), the suppression start determination unit 13 The distribution data is determined to be subjected to standard transfer processing (step S10). The average data transfer amount threshold Z is a value estimated or calculated according to the size of the reception buffer of the relay device 3. Specifically, the average data transfer amount threshold Z is estimated to increase the possibility that the reception buffer of the relay device 3 will overflow if the average data transfer amount transmitted to the relay device 3 is equal to or greater than the average data transfer amount threshold Z. Or a calculated value.

In the next suppression start determination process, the suppression start determination unit 13 calculates the total amount SUM (IF) of the distribution data that has not been received from the request device 2 among the distribution data that has already been transmitted to the request device 2. Whether or not the reception confirmation has been received is specified by whether or not an ACK (acknowledgement) in HTTP (Hypertext Transfer Protocol) communication is returned from the requesting device 2 to the distribution device 1. It can be seen that the data (packet) for which the ACK is returned from the requesting device 2 has reached the requesting device 2 after being transferred from the congestion suppressing device 10 to the relaying device 3. On the other hand, there is a possibility that data (packets) for which ACK is not returned from the requesting device 2 is still left in the buffer of the relay device 3. The suppression start determination unit 13 calculates the amount of data that is transferred from the congestion suppression device 10 toward the relay device 3 and has not yet reached the requesting device 2 by calculating SUM (IF). The suppression start determination unit 13 compares the SUM (IF) with the data amount indicating 90% of the reception buffer threshold Y of the relay device 3, and the SUM (IF) calculates 90% of the reception buffer threshold Y of the relay device 3. It is determined whether or not the data amount is larger (step S7). When the SUM (IF) is larger than the data amount indicating 90% of the reception buffer threshold Y of the relay device 3 (YES in Step S7), the suppression start determination unit 13 determines the transmission amount per unit time to the relay device 3. It determines with starting suppression control (step S8). On the other hand, when the SUM (IF) is equal to or less than the data amount indicating 90% of the reception buffer threshold Y of the relay device 3 (NO in step S7), the suppression start determination unit 13 performs standard transfer processing ( It is decided to carry out step S10).

In addition, before the process of step S7 is finally performed, distribution data that is candidates for suppression control is reduced in step S2, step S4, step S5, and step S6. With such a reduction, it is possible to narrow down the distribution data to be finally subjected to suppression control. Thereby, the load of the congestion suppression apparatus 10 by performing processes other than standard transfer control can be reduced. Note that one or more of the processes of step S2, step S4, step S5, and step S6 may not be performed. In step S4, step S5, step S6, and step S7, the suppression start determination unit 13 determines to perform standard transfer processing when the target value is equal to or less than the threshold value or a value based on the threshold value. However, in each of these steps, the suppression start determination unit 13 may determine that the standard transfer process is performed when the target value is less than the threshold value or a value based on the threshold value.

When it is determined that the standard transfer process is performed on the distribution data in the above process, the relay control unit 11 performs the standard transfer process on the distribution data with respect to the relay device 3 (step S10). This transfer process is controlled to distribute as much data as possible. The relay control unit 11 determines whether the transfer processing of the total amount of distribution data from the start of transmission of distribution data to the end of transmission has been completed (step S11). When completed (Yes in step S11), the process for the distribution data is terminated. The congestion suppression device 10 performs standard transfer processing until the transfer of the total amount of one piece of distribution data transmitted from one distribution device 1 is completed, and also performs the processing from step S3 on the distribution data. It may be performed repeatedly at the same time. When it is determined that the suppression control is started (Yes in step S7), the standard transfer process may be terminated for the distribution data and the suppression control may be performed.

According to the above-described processing, when there are five distribution devices 1 that are transmitting distribution data to the requesting device 2, the requesting device 2 is similar in order for the distribution data from each of the five distribution devices 1. Repeat the process. As a result, the delivery data transferred from the delivery device 1 to the congestion suppression device 10 and transferred to the relay device 3 earliest has a larger amount of data per unit time. On the other hand, the distribution data transferred to the relay device 3 after reaching the congestion suppression device 10 after the amount of data in the reception buffer of the relay device 3 approaches the reception buffer threshold Y is a unit compared to the previously transferred distribution data. The amount of data transferred per hour is small. When SUM (IF) becomes larger than the data amount indicating 90% of the reception buffer threshold Y of the relay device 3 (YES in step S7), suppression control is started.

Next, according to the flowchart of FIG. 8, the transmission amount suppression control per unit time to the relay device 3 (step S8) will be described.
When it is determined that the suppression start determination unit 13 starts the suppression control, the suppression control unit 14 performs suppression control on the distribution data (step S8). Specifically, the suppression control unit 14 sets an upper limit value L (Send Socket Buffer Memory Size) of the transmission buffer 16 of the congestion suppression device 10. The upper limit value L is an upper limit value of the transmission amount per unit time and is a transmission suppression amount. The suppression control unit 14 calculates the upper limit value L of the transmission buffer 16 by subtracting the SUM (IF) value per unit time from the reception buffer threshold value Y (the upper limit value of the reception buffer) of the relay device 3 per unit time. (Step S81). SUM (IF) is the amount of data that is transferred from the congestion suppression device 10 toward the relay device 3 and has not yet reached the requesting device 2. This amount of data is the amount of data that may still be stored in the relay device 3 as a buffer. Therefore, the suppression control unit 14 can calculate the amount of data that does not overflow the reception buffer of the relay device 3 by subtracting SUM (IF) from the reception buffer threshold Y (the upper limit value of the reception buffer). The suppression control unit 14 sets the calculated data amount to the upper limit value L of the transmission buffer 16 of the congestion suppression device 10 (step S82). Then, the suppression control unit 14 performs distribution data transfer processing so that the transmission amount per unit time becomes the upper limit value L (step S83). This prevents data from overflowing and being discarded in the reception buffer of the relay device 3.

On the other hand, when a large amount of data is still transmitted from the distribution apparatus 1 by the suppression control as described above, the amount of data staying in the reception buffer 15 in the congestion suppression apparatus 10 increases. However, it is assumed that the reception buffer 15 of the congestion suppression device 10 has a sufficiently large capacity compared to the amount of data that can be stored in the reception buffer of the relay device 3. Alternatively, the suppression control unit 14 may request the distribution apparatus 1 to reduce the transmission amount of distribution data per unit time.

The suppression control unit 14 determines whether or not the transfer of the total amount of distribution data has been completed (step S9). When the transfer processing of the total amount of distribution data is completed (YES in step S9), the suppression control processing for the distribution data is terminated. When the transfer of the total amount of distribution data has not been completed (NO in step S9), the suppression control unit 14 determines whether the value of SUM (IF) per unit time has changed (step S84). When the value of SUM (IF) fluctuates (YES in step S84), the suppression control unit 14 repeats the processes in steps S81 to S9. That is, the suppression control unit 14 subtracts a new SUM (IF) value per unit time from the reception buffer threshold Y (reception buffer upper limit value) of the relay device 3 and sets the value to the upper limit value L. Repeat the process.

In the above-described processing, the congestion suppression device 10 identifies each session of one or a plurality of distribution data for each IP address of the requesting device 2, and the upper limit of the initial window size is crossed between the plurality of sessions. Take control. Thereby, it is possible to increase the transmission efficiency of the distribution data distributed from the distribution device 1 by suppressing the overflow of the reception buffer of the relay device 3 located downstream (on the requesting device 2 side) on the communication path.
In addition, based on the total data amount of one session of distribution data, the congestion suppression device 10 controls the transmission amount per unit time for the distribution data indicated by the session when the total data amount is smaller than the threshold. Don't do it. Thereby, transmission efficiency can be improved by not performing suppression control about the delivery data with comparatively small total data amount. In other words, the congestion suppression device 10 does not impose restrictions on distribution data sessions that do not have a detrimental effect such as buffer overflow in the relay device 3 and have a small file capacity and a small number of communication such as one round-trip communication. Partition delivery. This promotes resource release. On the contrary, the congestion suppression device 10 confirms the existence of a parallel delivery session for the delivery data of a large file with a residence risk, and stays within the delivery upper limit of the total amount of delivery data indicated by the parallel number. Control the amount of data. As a result, retransmission and reproduction timeout can be avoided and transmission efficiency can be improved.

Further, the processing of the congestion suppression device 10 described above is based on the amount of staying data (Inflight) that has not reached the requesting device 2 out of the data amount transmitted from the congestion suppression device 10 to the relay device 3 for each session (communication path). The amount of data per unit time that the congestion suppression device 10 transmits to the relay device 3 is controlled using (IF) amount, amount of unacknowledged reception confirmation data) as determination criteria. When judging only by the accumulation of the congestion window size, the memory size of the socket that is the sending interface, etc., even if there is no stagnation, it is suppressed by the number of sessions. You may be invited. The congestion suppression apparatus 10 can avoid this adverse effect.

Further, according to the above-described processing, the congestion suppression apparatus 10 relays distribution data between routes having different network characteristics. Then, in order to improve the transmission efficiency in this transmission relay, the congestion suppression apparatus 10 performs the transmission protocol termination process for the distribution data received from the broadband network, and changes the state of the transmission efficiency on the low band side (narrow band side). Monitor and control the delivery amount of each session in consideration of the retention rate and the data transmission status for the same destination. As a result, the overflow of the reception buffer in the relay apparatus 3 having a small-capacity buffer that becomes a resource bottleneck is mitigated or avoided. Further, when the data capacity of the distribution data to be transferred is small (specifically, about 10 KB), the transmission time (TAT: Turn Around Time) by the relay device 3 is short even if the delay rate starts to increase, so that the efficiency due to the stay is increased. The influence of the decrease can also be reduced.

FIG. 9 is a diagram illustrating a minimum configuration of the congestion suppression device according to the embodiment.
As shown in this figure, the congestion suppression device 10 includes at least a data specifying unit 12 and a suppression start determination unit 13.

Each of the above devices has a computer system inside. A program for causing each device to perform each process described above is stored in a computer-readable recording medium of each device, and the program is read and executed by the computer of each device. Is done. Here, the computer-readable recording medium means a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like.
Alternatively, the computer program may be distributed to the computer via a communication line, and the computer that has received the distribution may execute the program.

Further, the program may be a program for realizing a part of the functions of each processing unit described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

This application claims priority based on Japanese Patent Application No. 2016-185260 filed in Japan on September 23, 2016, the entire disclosure of which is incorporated herein.

DESCRIPTION OF SYMBOLS 1 ... Distribution apparatus 2 ... Request apparatus 3 ... Relay apparatus 10 ... Congestion suppression apparatus 11 ... Relay control part 12 ... Data specification part 13 ... Suppression start determination part 14 ... · Suppression control unit 15 ··· reception buffer 16 ··· transmission buffer 20 ··· first communication network 30 ··· second communication network

Claims

A data specifying unit for specifying distribution data transmitted from one or a plurality of distribution apparatuses to the request apparatus based on the identification information of the request apparatus;
Of the distribution data that has already been transmitted to the requesting device, the amount of distribution data that has not received reception confirmation from the requesting device, and the congestion suppression device and the request on the communication path between the distribution device and the requesting device Whether to start suppression control of the transmission amount per unit time to the relay device based on the comparison result with the suppression start threshold set in the reception buffer of the relay device provided on the communication path with the device A suppression start determination unit for determining,
Congestion suppression apparatus comprising:
After determining to start the suppression control, calculate a transmission suppression amount per unit time that the data amount of the reception buffer of the relay device does not exceed the upper limit set in the reception buffer, and according to the transmission suppression amount A suppression control unit that transmits the distribution data received from the one or more distribution devices to the relay device;
The congestion suppression apparatus according to claim 1, comprising:
The suppression start determination unit determines whether the total amount of data from the transmission start to the transmission end of the distribution data transmitted to the requesting device received from the one or more distribution devices is equal to or greater than a first threshold, The congestion suppression device according to claim 1 or 2, wherein when the total amount of data is equal to or greater than the first threshold, it is determined whether or not the suppression control is to be started.
The suppression start determination unit determines whether a transmission amount per unit time of the distribution data transmitted to the requesting device is equal to or larger than a second threshold, and the transmission amount per unit time is equal to or larger than the second threshold. In this case, it is determined whether or not the suppression control is started. The congestion suppression device according to any one of claims 1 to 3.
The suppression start determination unit determines whether an average value of a transmission amount per unit time of the distribution data transmitted to the requesting device is greater than or equal to a third threshold, and the average value is the third threshold The congestion suppression apparatus according to any one of claims 1 to 4, wherein if it is the above, it is determined whether or not the suppression control is started.
Based on the identification information of the requesting device, identify the distribution data transmitted from the one or more distribution devices to the requesting device,
Of the distribution data that has already been transmitted to the requesting device, the amount of distribution data that has not received reception confirmation from the requesting device, and the own device and the requesting device on the communication path between the distribution device and the requesting device To determine whether or not to start suppression control of the transmission amount per unit time to the relay device based on the comparison result with the suppression start threshold set in the reception buffer of the relay device provided on the communication path Congestion suppression method.
On the computer,
Based on the identification information of the requesting device, identify the distribution data transmitted from the one or more distribution devices to the requesting device,
Of the distribution data that has already been transmitted to the requesting device, the amount of distribution data that has not received reception confirmation from the requesting device, and the own device and the requesting device on the communication path between the distribution device and the requesting device To determine whether or not to start suppression control of the transmission amount per unit time to the relay device based on the comparison result with the suppression start threshold set in the reception buffer of the relay device provided on the communication path To
A program that executes processing.