JP4704147B2 - Traffic control device, traffic control method, and computer program - Google Patents

Description

  The present invention relates to a traffic control device, a traffic control method, and a computer program.

Conventionally, a traffic control method called a token bucket is known (for example, see Non-Patent Document 1). The token bucket includes a token buffer that accumulates tokens, and controls traffic flow according to the amount of tokens accumulated in the token buffer. The token bucket control parameters include a “token rate” that is a rate at which tokens are input to the token buffer and a “token bucket size” that is the size of the token buffer. The token rate defines the average rate of traffic flow. The token bucket size defines the maximum burst length of traffic flow.
A. Parekh, R. Gallerger, “A generalized processor sharing approach to flow control in integrated services network: the single node case”, IEEE / ACM transaction on Networking vol.1, no.3, Jun-93.

  However, in the traffic control using the above-described conventional token bucket, only local traffic control using the average rate and the maximum burst length can be realized, and there is a problem of lack of flexibility. In other words, by limiting the average rate, the amount of traffic flowing into the network is limited to a certain level or less when viewed on average over a long period of time, and the amount of traffic flowing into the network instantaneously by limiting the maximum burst length Can be limited to below a certain level. However, it cannot meet various user requirements such as usability of interactive applications.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a traffic control device and a traffic control method capable of improving the flexibility of traffic control using a token bucket. is there.

  Another object of the present invention is to provide a computer program for realizing the traffic control device of the present invention using a computer.

In order to solve the above problems, a traffic control device according to the present invention has a buffer size (token bucket size) that defines the maximum burst length of traffic flow, and a rate (token rate) that defines an average rate of traffic flow. ) and token buffer for storing tokens that are input in a packet buffer for storing packets input, said to read out the packets from the packet buffer according to the amount of tokens accumulated in the token buffer, read A plurality of token buckets having a buffer reading means for outputting packets, a classifier that classifies input packets into a plurality of predetermined classes, outputs packets by class, and a transmitter that outputs flow-limited packets to the network and, equipped with, before The packet output from the classifier by class is input to the token bucket corresponding to each class, the packet output from the token bucket of each class is input to the token bucket for integration, and output from the token bucket for integration. The received packet is input to the transmitter .

The traffic control method according to the present invention has a buffer size (token bucket size) that defines the maximum burst length of traffic flow, and accumulates tokens that are input at a rate (token rate) that defines an average rate of traffic flow. and token buffer, a packet buffer for storing packets input to read out the packets from the packet buffer according to the amount of tokens accumulated in the token buffer, and a buffer read means for outputting the read packet A plurality of traffic flow restriction processes for restricting traffic flow using token buckets , classifying input packets into a plurality of predetermined classes, outputting packets by class, and outputting packets output by class Traffic corresponding to a class The packet output from the traffic flow restriction process of each class is input to the traffic flow restriction process for integration, and the packet output from the traffic flow restriction process for integration is output to the network. to, characterized in that.

A computer program according to the present invention has a buffer size (token bucket size) that defines the maximum burst length of traffic flow, and stores tokens that are input at a rate (token rate) that defines an average rate of traffic flow It has a buffer, a packet buffer for storing packets input to read out the packets from the packet buffer according to the amount of tokens accumulated in the token buffer, and a buffer read means for outputting the read packet a plurality of traffic flow restriction function for traffic flow restriction using token bucket, classifies the input packet to a predetermined plurality of classes, and a classifier function of outputting a packet by class, the flow restriction packets to the network And the packet output from each class from the classifier function is input to the traffic flow restriction function corresponding to each class, and the packet output from the traffic flow restriction function of each class is input to the traffic flow restriction for integration. And a function of inputting a packet output from the traffic flow restriction function for integration into the transmitter function .

  According to the present invention, it is possible to improve the flexibility of traffic control using a token bucket.

Hereinafter, embodiments of the present invention will be sequentially described with reference to the drawings.
[First Embodiment]
FIG. 1 is a block diagram showing a configuration of a traffic control device 1a according to the first embodiment of the present invention. In the first embodiment, a plurality of token buckets are connected in series.
In FIG. 1, the traffic control device 1 a has two token buckets 10-1 and 10-2 (hereinafter referred to as “token bucket 10” unless otherwise distinguished). The token buckets 10-1 and 10-2 are connected in series.

The token bucket 10 includes a packet buffer 11, a token buffer 12, and a buffer reading unit 13.
The packet buffer 11 accumulates the packet Pa input to the token bucket 10.
The token buffer 12 stores tokens. A token is input to the token buffer 12 at a token rate r. In addition, a token bucket size b which is the size of the token buffer 12 is set. The token rate r and the token bucket size b can be individually set for each of the token buckets 10-1 and 10-2.
The buffer reading unit 13 reads the packet Pa from the packet buffer 11 according to the amount of tokens accumulated in the token buffer 12, and outputs the read packet Pa.

  The packet Pa input to the traffic control device 1a in FIG. 1 is first subjected to traffic flow restriction in the first-stage token bucket 10-1. The packet Pa after the output of the token bucket 10-1 is input to the second-stage token bucket 10-2, and is output after being restricted in traffic flow in the second-stage token bucket 10-2.

  According to the first embodiment described above, first, the traffic flow rate of input traffic is limited by the first-stage token bucket 10-1. Next, for the traffic restricted by the first stage, the traffic flow rate is further restricted by the second-stage token bucket 10-2. As a result, two-level traffic control using the token rate r (average rate of traffic flow) and token bucket size b (maximum burst length of traffic flow) can be performed, and more flexible traffic control can be performed. It becomes.

  In the configuration example of FIG. 1 described above, the serial two-stage configuration of the token bucket 10 is given as an example, but a further series multi-stage configuration (three or more stages) is also possible.

[Second Embodiment]
FIG. 2 is a block diagram showing the configuration of the traffic control device 1b according to the second embodiment of the present invention. In FIG. 2, the same reference numerals are given to portions corresponding to the respective portions in FIG. In the second embodiment, a plurality of token buckets are connected in parallel.
In FIG. 2, the traffic control device 1 b includes two token buckets 10-1 and 10-2, a classifier 21 and a transmitter 22. The token buckets 10-1 and 10-2 are connected in parallel via a classifier 21 on the input side and a transmitter 22 on the output side.

The classifier 21 classifies the packet Pa input to the traffic control device 1b into individual QOS (Quality Of Service) classes. Then, the classified packet Pa is distributed to the token buckets 10-1 and 10-2 associated with each QoS class and output.
The transmitter 22 collectively outputs the packets Pa output from the token buckets 10-1 and 10-2 in one system.

  According to the second embodiment described above, the token buckets 10-1 and 10-2 can be selectively used according to the QoS class, and traffic flow restriction suitable for each QoS class can be performed.

In the configuration example of FIG. 2 described above, the parallel two-stage configuration of the token bucket 10 is given as an example, but a further parallel multi-stage configuration (three or more stages) is also possible.
In the above-described example, the classifier 21 performs classification based on the QOS class. However, other classification such as for each application may be performed.

[Third Embodiment]
FIG. 3 is a block diagram showing a configuration of a traffic control device 1c according to the third embodiment of the present invention. 3, parts corresponding to those in FIGS. 1 and 2 are denoted by the same reference numerals, and the description thereof is omitted. In the third embodiment, a plurality of token buckets are connected in series and in parallel.
In FIG. 3, the traffic control device 1 c includes three token buckets 10-1 to 10-3, a classifier 21, and a transmitter 22.

  The packets Pa classified by the classifier 21 are input to the corresponding token buckets 10-1 and 10-2, respectively. Each of the token buckets 10-1 and 10-2 performs individual traffic flow restriction on the input packet Pa. The packet Pa after output of the token buckets 10-1 and 10-2 is input to the token bucket 10-3. The token bucket 10-3 performs a unique traffic flow restriction on the input packet Pa. The packet Pa after output of the token bucket 10-3 is input to the transmitter 22.

  Further, a part of the packet Pa classified by the classifier 21 is input to the transmitter 22 without passing through the token buckets 10-1 to 10-3.

  According to the third embodiment described above, the traffic control function according to the classification of the QoS class or the like by the parallel connection configuration of the token buckets 10-1 and 10-2, and the token buckets 10-1, 10-2 and 10-3. It is possible to have a two-stage traffic control function by the serial connection configuration. Thereby, the further flexibility improvement of traffic control is realizable.

  In the configuration example of FIG. 3 described above, a two-stage configuration is given as an example for both the serial and parallel token buckets 10, but a multi-stage configuration (three or more stages) is also possible. Further, the number of stages of series connection and parallel connection may be different.

[Fourth Embodiment]
FIG. 4 is a block diagram showing a configuration of a traffic control device 1d according to the fourth embodiment of the present invention. In FIG. 4, parts corresponding to those in FIG. 1 are given the same reference numerals, and explanation thereof is omitted. In FIG. 4, the classifier 21 that classifies the input packet of the traffic control device 1d is omitted.

  In the first to third embodiments described above, individual traffic control is performed for each token bucket 10, but in the fourth embodiment, traffic control using a plurality of token buckets is integrated.

  In FIG. 4, the traffic control device 1 d includes three token buckets 100-1 to 3 (hereinafter referred to as “token bucket 100” unless otherwise distinguished) and a control unit 31. In the token buckets 100-1 to 100-3, the token buckets 100-1 and 100-2 are arranged in parallel, and the token buckets 100-1 and 100- 2 and 100-3 are connected in series.

  The token bucket 100 has the same configuration as the token bucket 10 of the first to third embodiments described above, but the buffer reading unit 13 reads a packet from the packet buffer 11 in accordance with an instruction from the control unit 31.

  The control unit 31 performs packet read control from the packet buffers 11 of the token buckets 100-1 to 100-3 by combining the token amounts stored in the token buffers 12 of the token buckets 100-1 to 100-3. Then, a read control instruction as a result of the read control is output to the buffer read unit 13 of each token bucket 100-1 to 100-3.

  According to the above-described fourth embodiment, it is possible to perform traffic control by integrating the amount of tokens accumulated in the token buffer 12 of each token bucket 100-1 to 100-3. As a result, various traffic controls can be realized.

  In the configuration example of FIG. 4 described above, a two-stage configuration is given as an example for both the serial and parallel token buckets 100, but a multi-stage configuration (three or more stages) is also possible. Further, the number of stages of series connection and parallel connection may be different.

  Also, the control unit 31 reads out the packet from the packet buffer 11 of each token bucket 100 by summing the amount of tokens stored in the token buffer 12 of all or part of the token bucket 100 in the traffic control device 1d. Control may be performed.

[Fifth Embodiment]
FIG. 5 is a block diagram showing a configuration of a traffic control device 1e according to the fifth embodiment of the present invention. In FIG. 5, parts corresponding to those in FIG. 4 are denoted by the same reference numerals, and description thereof is omitted. In FIG. 5, the classifier 21 that classifies the input packets of the traffic control device 1e and the transmitter 22 that outputs the output packets of the traffic control device 1e in a single system are omitted.

  In the fifth embodiment, a modification is shown in the case where traffic control by a plurality of token buckets is integrated.

  In FIG. 5, the traffic control device 1e includes a combination of a packet buffer 11-1 and a buffer reading unit 13-1, a combination of a packet buffer 11-2 and a buffer reading unit 13-2, and three token buffers 12-1 to 12-1. 3 and a control unit 31.

The packet buffers 11-1 and 11-2 are respectively input with the corresponding system packet Pa.
The token buffer 12-1 is used for read control from the packet buffer 11-1. The token buffer 12-2 is used for read control from the packet buffer 11-2. The token buffer 12-2 is used for both read control from the packet buffer 11-1 and read control from the packet buffer 11-2.

  The control unit 31 performs read control from the packet buffer 11-1 according to the amount of tokens accumulated in the token buffers 12-1 and 12-3. Further, reading from the packet buffer 11-1 is controlled according to the amount of tokens accumulated in the token buffers 12-2 and 12-3.

  According to the fifth embodiment described above, each of the packet buffers 11-1 and 11 depends on the token rate r (average rate of traffic flow) and the token bucket size b (maximum burst length of traffic flow) related to the token buffer 12-3. -2 can be integrated and controlled.

In the configuration example of FIG. 5 described above, the parallel two-stage configuration of the packet buffer 11 is given as an example, but a further parallel multi-stage configuration (three or more stages) is also possible.
In the configuration example of FIG. 5 described above, a parallel multi-stage configuration is used, but the present invention can be similarly applied to a series multi-stage configuration.

  Further, the control unit 31 may control the packet reading from each packet buffer 11 by summing up the amount of tokens accumulated in all or some of the token buffers 12 in the traffic control device 1e.

  The plurality of token buffers 12 may include a token buffer 12 corresponding to each of the packet buffers 11 and a token buffer 12 corresponding to all or some of the packet buffers 11. For example, the token buffers 12-1 and 12-2 are provided corresponding to the packet buffers 11-1 and 11-2, respectively, but the token buffer 12-3 includes only one packet buffer 11 (for example, only the packet buffer 11-1). ) Packet read control.

[Sixth Embodiment]
FIG. 6 is a block diagram showing a configuration of a traffic control device 1f according to the sixth embodiment of the present invention. In FIG. 6, parts corresponding to those in FIG. 5 are denoted by the same reference numerals, and description thereof is omitted. In FIG. 6, the classifier 21 that classifies the input packet of the traffic control device 1f is omitted.

  In the sixth embodiment, another modification example in which traffic control by a plurality of token buckets is integrated is shown.

  In FIG. 6, the traffic control device 1 f includes one packet buffer 11, its buffer reading unit 13 a, three token buffers 12-1 to 12-1, and a control unit 31.

Two packets Pa-1 and Pa-2 are input to the packet buffer 11.
The token buffer 12-1 is used for reading control of the packet Pa-1 from the packet buffer 11. The token buffer 12-2 is used for reading control of the packet Pa-2 from the packet buffer 11. The token buffer 12-2 is used for both read control of the packet Pa-1 from the packet buffer 11 and read control of the packet Pa-2 from the packet buffer 11.

  The control unit 31 performs reading control of the packet Pa-1 from the packet buffer 11 according to the amount of tokens accumulated in the token buffers 12-1 and 12-3. Further, reading control of the packet Pa-2 from the packet buffer 11 is performed according to the amount of tokens accumulated in the token buffers 12-2 and 12-3.

  The buffer reading unit 13a reads packets Pa-1 and Pa-2 from the packet buffer 11 in accordance with instructions from the control unit 31.

  According to the sixth embodiment described above, individual traffic control for the two systems of packets Pa-1 and Pa-2 classified by the QoS class or the like can be realized in a configuration including only one packet buffer 11. .

  In the configuration example of FIG. 6 described above, the input system of the packet to the packet buffer 11 is two systems, but further multiple systems (three systems or more) are also possible.

  Further, the control unit 31 may control reading of packets from the packet buffer 11 by summing up the amount of tokens accumulated in all or part of the token buffer 12 in the traffic control device 1f.

  The plurality of token buffers 12 may include a token buffer 12 corresponding to each packet input system and a token buffer 12 corresponding to all or a part of the packet input systems. For example, the token buffers 12-1 and 12-2 are provided corresponding to the packets Pa-1 and Pa-2, respectively, but the token buffer 12-3 is a packet of only one packet Pa (for example, only the packet Pa-1). It may be used for read control.

[Seventh Embodiment]
FIG. 7 is a block diagram showing a configuration of a traffic control device 1g according to the seventh embodiment of the present invention. In FIG. 7, parts corresponding to those in FIGS. 1 and 3 are denoted by the same reference numerals, and description thereof is omitted. In FIG. 7, the classifier 21 that classifies the input packet of the traffic control device 1g is omitted.

  In the first to sixth embodiments described above, the token rate r (average rate of traffic flow) of the token buffer 12 is fixed, but in the seventh embodiment, the token rate r is variable.

  In FIG. 7, the traffic control device 1g has substantially the same configuration as the traffic control device 1c of FIG. However, the traffic control device 1g of FIG. Further, the token rate changing unit 42 is provided in the token buckets 10-1 and 10-2 of the traffic control device 1g.

The token rate control unit 41 controls the token rate r of the token buckets 10-1 and 10-2 based on the state value x of the token bucket 10-3. For example, a predetermined function f (x) is defined, and the value of the function f (x) is a token rate r. As an example of the function f (x),
f (x) = ax ^b + c,
Is available. However, a, b, and c are constants that can be arbitrarily set.
Moreover, as the state value x of the token bucket 10,
(1) the amount of tokens stored in the token buffer 12,
(2) the number of bytes of the packet stored in the packet buffer 11,
(3) the number of packets stored in the packet buffer 11,
Etc. are available.

  In addition, when the maximum value or minimum value of the token rate r is set, and the value of the function f (x) exceeds the range specified by the maximum value or minimum value, the token rate is set so as to fall within the range. The value of r may be corrected.

  The token rate control unit 41 determines the token rate r of the token buckets 10-1 and 10-2 based on the state value x of the token bucket 10-3, and uses the determined token rate r as the token buckets 10-1 and 10−. 2 is instructed.

  The token rate changing unit 42 of the token buckets 10-1 and 10-2 changes the token rate r according to the instruction of the token rate r from the token rate control unit 41. Thereby, the token rate r of the token buffer 12 of the token buckets 10-1 and 10-2 is updated.

  According to the seventh embodiment described above, traffic control in which the state of a certain token bucket 10 is reflected in the token rate r (the average rate of traffic flow) of other token buckets 10 can be realized. This makes it possible to dynamically change the traffic flow limit.

  The token bucket 10 that refers to the state value can be arbitrarily selected. The number of selections may be at least one, and the state values of a plurality of token buckets 10 may be referred to.

  Further, another token bucket 10 that reflects the state of a certain token bucket 10 can be arbitrarily selected. The number of selections may be one or more.

  In addition, it is possible to combine the 1st-7th embodiment mentioned above suitably.

Moreover, the program for implement | achieving the function of the traffic control apparatus shown in any of FIGS. 1-7 is recorded on a computer-readable recording medium, and the program recorded on this recording medium is read into a computer system, You may perform a traffic control process by performing. Here, the “computer system” may include an OS and hardware such as peripheral devices.
Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used.
The “computer-readable recording medium” means a flexible disk, a magneto-optical disk, a ROM, a writable nonvolatile memory such as a flash memory, a portable medium such as a CD-ROM, a hard disk built in a computer system, etc. This is a storage device.

Further, the “computer-readable recording medium” means a volatile memory (for example, DRAM (Dynamic DRAM) in a computer system that becomes a server or a client when a program is transmitted through a network such as the Internet or a communication line such as a telephone line. Random Access Memory)), etc., which hold programs for a certain period of time.
The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.
The program may be for realizing a part of the functions 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.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design changes and the like within a scope not departing from the gist of the present invention.

It is a block diagram which shows the structure of the traffic control apparatus 1a which concerns on 1st Embodiment of this invention. It is a block diagram which shows the structure of the traffic control apparatus 1b which concerns on 2nd Embodiment of this invention. It is a block diagram which shows the structure of the traffic control apparatus 1c which concerns on 3rd Embodiment of this invention. It is a block diagram which shows the structure of the traffic control apparatus 1d which concerns on 4th Embodiment of this invention. It is a block diagram which shows the structure of the traffic control apparatus 1e which concerns on 5th Embodiment of this invention. It is a block diagram which shows the structure of the traffic control apparatus 1f which concerns on 6th Embodiment of this invention. It is a block diagram which shows the structure of the traffic control apparatus 1g which concerns on 7th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a-1g ... Traffic control apparatus 10,100 ... Token bucket, 11 ... Packet buffer, 12 ... Token buffer, 13 ... Buffer reading part, 21 ... Classifier, 22 ... Transmitter, 31 ... Control part, 41 ... Token rate control part 42 ... token rate changing unit, b ... token bucket size, r ... token rate, Pa ... packet

Claims (3)

A token buffer that has a buffer size (token bucket size) that specifies the maximum burst length of traffic flow, stores tokens that are input at a rate (token rate) that specifies the average rate of traffic flow, and an input packet A plurality of token buckets having a packet buffer to be accumulated, and a buffer reading means for reading packets from the packet buffer according to the amount of tokens accumulated in the token buffer and outputting the read packets,
A classifier that classifies input packets into a plurality of predetermined classes and outputs packets by class,
A transmitter for outputting a flow-limited packet to the network,
Packets output by class from the classifier are input to the token bucket corresponding to each class, packets output from the token bucket of each class are input to the token bucket for integration, and output from the token bucket for integration The received packet to the transmitter,
A traffic control device. A token buffer that has a buffer size (token bucket size) that specifies the maximum burst length of traffic flow, stores tokens that are input at a rate (token rate) that specifies the average rate of traffic flow, and an input packet Traffic flow restriction using a token bucket having a packet buffer to be accumulated and a buffer reading means for reading the packet from the packet buffer according to the amount of token accumulated in the token buffer and outputting the read packet Have multiple traffic flow restriction processes,
The input packets are classified into a plurality of predetermined classes, the packets are output for each class, the packets output for each class are input to the traffic flow restriction process corresponding to each class, and the traffic flow restriction process for each class The packet output from is input to the traffic flow restriction process for integration, and the packet output from the traffic flow restriction process for integration is output to the network.
A traffic control method characterized by the above. A token buffer that has a buffer size (token bucket size) that specifies the maximum burst length of traffic flow, stores tokens that are input at a rate (token rate) that specifies the average rate of traffic flow, and an input packet Traffic flow restriction using a token bucket having a packet buffer to be accumulated and a buffer reading means for reading the packet from the packet buffer according to the amount of token accumulated in the token buffer and outputting the read packet With multiple traffic flow restriction functions,
Classifier function that classifies input packets into a plurality of predetermined classes and outputs packets by class,
A transmitter function that outputs the flow-limited packets to the network;
Packets output by class from the classifier function are input to the traffic flow restriction function corresponding to each class, and packets output from the traffic flow restriction function of each class are input to the traffic flow restriction function for integration. A function of inputting packets output from the traffic flow restriction function for integration to the transmitter function;
A computer program for causing a computer to realize the above.

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