KR100745682B1 - I/o packet control device and method of line card in packet exchange system - Google Patents

Abstract

The present invention relates to an input / output packet control apparatus and a method of a line card for controlling a packet traffic amount by applying a rate limit function to a packet input and output to a line card of a packet switching system. According to the present invention, a packet classification unit for classifying each input packet according to a set input / output traffic limit ratio, and controls the input traffic amount of the classified packets, and is provided from an output port of at least one line card in a packet switching system. When a packet having the same information is input according to the output bandwidth excess traffic information, when a packet including the first traffic restriction unit for controlling the throughput of the packet and the identification information necessary for output rate restriction is input from the destination line card, Limited output band by judging whether the set bandwidth is exceeded for the traffic of the input packet And a second traffic limiter for providing output bandwidth exceeded traffic information to the first traffic limiter of at least one or more line cards in a packet switched system for traffic exceeding width.

Packet switching system, line card, ingress restriction, egress restriction.

Description

I / O PACKET CONTROL DEVICE AND METHOD OF LINE CARD IN PACKET EXCHANGE SYSTEM}

1 is a block diagram showing the structure of a general packet switching system;

FIG. 2 is a block diagram illustrating a structure of a line card according to the prior art having a traffic rate limit function for input / output packets in the general packet switching system shown in FIG. 1;

3 is a block diagram showing a structure of an input / output packet control apparatus of a line card in a packet switching system according to an embodiment of the present invention.

4 is a flowchart illustrating an operation of a line card for input control in a packet switching system according to an embodiment of the present invention;

5A and 5B are flow charts illustrating the operation of a line card for output control in a packet switched system in accordance with an embodiment of the invention.

<Explanation of symbols for the main parts of the drawings>

100: line card 200: switching fabric

300: control card 110: packet classification unit

120: ingress limit unit 121, 141: monitoring module

122: treatment module 130: packet forwarding unit

140: egress restriction unit 140: output packet processing unit

The present invention relates to an input and output packet control apparatus and method for a line card, and more particularly, to input and output packets to and from the line card by applying a rate limit (Rate Limit) function to control the amount of packet traffic A packet controller and a method thereof are provided.

The rate limit function limits the amount of packets of a particular traffic input and output through the packet switch, allowing other more important traffic to use the communication bandwidth. By controlling the traffic by using the rate limit function, it is possible to efficiently use the communication network and equipment, and to realize the differentiated charging policy according to the communication bandwidth.

In general, classification criteria for traffic to which the rate limit function is applied may be based on a physical input / output port through which a packet is input or output, or based on information of a packet header. Information in the packet header may include source / destination IP address, protocol number, source / destination port number of Transmission Control Protocol (TCP) or User Datagram Protocol (UDP), VLAN tag ( Virtual Local Area Network Tag) and MPLS Label Information (Multi-Protocol Label Switching Label Information). The information of the packet header can be set individually or a combination of the target traffic to limit the bandwidth.

The rate limiting operation for the specific traffic classified as a result of packet classification is based on the input rate limit for the purpose of limiting the specific traffic coming into the input terminal of the system and the specific traffic output to the outside through the output terminal of the system. It can be divided into two types of output rate limit.

For example, when a packet switcher is located at the edge of a network, the input rate limit is intended to prevent traffic from a particular source from entering the network at a rate higher than the preset bandwidth. It is used to prevent traffic destined for a specific destination from leaking out of the network at a higher rate than the preset bandwidth.

Such a general packet switching system will be described with reference to the accompanying drawings.

1 is a block diagram showing the structure of a general packet switching system.

Referring to FIG. 1, the packet exchange system may include a plurality of line cards 100, a switching fabric 200, and a control card 300.

The line card 100 directly processes data packets inputted and outputted to the system, and the switching fabric 200 inputs the line card to which the output terminal to which the packet inputted to the input terminal of a certain line card 100 belongs. Forwards the data packet.

And the control card 300 is to manage the path selection information for the delivery of packets by the switching fabric 200 and various variables that should be set for the line card 100 and the switching fabric 200 to operate normally. . Here, a detailed configuration and operation of the line card in the packet switching system will be described with reference to FIG. 2. In this case, since other components are not highly related to the present invention, detailed description thereof will be omitted.

FIG. 2 is a block diagram illustrating a structure of a line card according to the related art having a traffic rate limit function for input / output packets in the general packet switching system illustrated in FIG. 1.

Referring to FIG. 2, the line card 100 includes a packet classification unit 110, an ingress limiting unit 120, a packet forwarding unit 130, an egress limiting unit 140, and the like. An output packet processing unit 150 is included. Here, the ingress limiter 120 may include a monitoring module 121 and a treatment module 122, and the egress limiter 140 may also include a monitoring module 142 and a treatment module 141.

The packet classifier 110 classifies a packet input to the line card 110 into a packet requiring an input rate or an output rate limit according to a preset classification criterion. Here, by selecting or marking specific numbers of the selected packets, it is possible to know the processing criteria according to the classification criteria of the corresponding packets later.

Meanwhile, the packet classifier 110 outputs the traffic selected by the input rate limit to the monitoring module 121 of the ingress limiter 120, and the traffic that does not need to limit the input rate to the ingress limiter 120. It is output to the packet forwarding unit 130 without passing through.

The monitoring module 121 of the ingress limiting unit 120 determines whether the preset bandwidth limit is exceeded for the traffic output from the packet classifying unit 110, and when it is determined that the packet exceeds the set bandwidth, the treatment module 121. Discard the traffic at 122. If the packet inputted as a result of the determination by the monitoring module 121 is not a packet exceeding a preset bandwidth, the ingress limiter 122 provides the packet to the packet forwarding unit 130.

Traffic passing through the ingress limiter 120 and the traffic not passing through the ingress limiter 120 are transmitted through the packet forwarding processor 130 and the switching fabric 200 shown in FIG. 1. Sent to the destination line card.

On the other hand, if a packet having a number or indication corresponding to the output rate limit in the destination line card is input through the packet forwarding unit 130, the monitoring module 142 and the treatment module 141 of the egress limit unit 140 The packet is processed in the same manner as the operations of the monitoring module 121 and the treatment module 122 of the ingress limiting unit 120 and output to the source line card through the output packet processing unit 150.

As described above, according to the packet rate limit scheme according to the related art, the packet exceeding the bandwidth is discarded by the egress limiting unit 140 for the output rate limiting traffic, and thus the packet exceeding the bandwidth is transmitted to the egress limiting unit 140. There is a problem in that it consumes processing and memory resources inside the system and burdens the switching fabric 200 until it arrives.

In addition, the traffic subject to the output rate limit is output to the output port of one line card, but may be input through multiple line cards in the use of a packet switch. Therefore, the conventional rate limiting technique imposes a restriction on the packets that are aggregated at the output stage. Therefore, there is a problem in that it is impossible to impose a restriction on the individual traffic input to each line card.

Accordingly, an object of the present invention is to provide a rate limit function for a particular traffic input or output to a communication network packet switch, without wasting resources of the system, and to ensure the fair discarding of traffic exceeding the output rate. The present invention provides a packet controller and a method thereof.

According to an aspect of an input / output packet control apparatus for a line card according to the present invention for achieving the above object, a packet classification unit for classifying the input packets according to the set input and output traffic limit rate, and the input traffic of the classified packets A first traffic limiter for controlling the amount and controlling the amount of processing of the packet when a packet having the same information is input according to the output bandwidth excess traffic information provided from the output port of at least one line card in the packet switching system; And, when a packet including identification information necessary for output rate limiting is input from the destination line card, it is determined whether the bandwidth set for the traffic of the input packet is exceeded and the output bandwidth exceeding traffic for the traffic exceeding the limited output bandwidth. Information in at least one line card in the packet switching system. It may include a second traffic restriction provided to the first traffic restriction.

The packet classification in the packet classification unit is classified according to physical ports to which an input or output of a packet is input or classified according to header information of the packet.

Packet classification according to the packet header information is classified individually or in combination according to source / destination IP address, protocol number, source / destination port number of TCP or UDP, VLAN tag, and MPLS label information.

The output bandwidth excess traffic information includes at least one of traffic identifier information and bandwidth excess rate information.

The second traffic limiter includes a buffer that temporarily stores the input packet to mitigate the bandwidth excess when the traffic for the input packet temporarily exceeds the set bandwidth.

The first traffic limiter of the at least one line card discards the packet according to an excess rate exceeding the output bandwidth. Here, the discarded packet can be randomly selected.

Discarding the packet at the first traffic limiter is continued until no output bandwidth excess traffic information is received at the second traffic limiter of the at least one linecard, and the second of the at least one linecard. The provision of output bandwidth excess traffic information from the traffic restriction section to the first traffic restriction section of the at least one line card is provided only at a set period or when an output bandwidth excess phenomenon occurs.

On the other hand, according to an aspect of the input and output packet control method in a packet switching system having at least one line card according to the present invention, the step of classifying each of the packets input to the line card according to the set I / O traffic limit, Controlling the amount of input traffic of the classified packets to be transmitted to the destination line card, and when a packet including identification information necessary for output rate limitation is input from the destination line card, the amount of the bandwidth set for the traffic of the input packet is input. Determining whether excess is exceeded and providing output bandwidth excess traffic information to at least one line card in a packet switching system for traffic exceeding a limited output bandwidth; Same as the output bandwidth exceeded traffic information If the packet having the input may include the step of controlling the traffic volume of the packet.

In the step of providing the output bandwidth excess traffic information to at least one or more line cards in a packet switching system, if the traffic for the incoming packet temporarily exceeds a set bandwidth, temporarily storing it in a buffer to mitigate the bandwidth excess. And then outputting further.

Hereinafter, a preferred embodiment of an input / output packet control apparatus and a method of a line card according to the present invention will be described in detail.

As shown in FIG. 1, the packet switching system includes a plurality of line cards that transmit / receive traffic in association with a switching fabric. With reference to the accompanying drawings, a structure of a line card as an apparatus for controlling an input / output packet according to an embodiment of the present invention for a plurality of such line cards will be described.

3 is a block diagram illustrating a structure of an input / output packet control apparatus of a line card in a packet switching system according to an exemplary embodiment of the present invention.

Referring to FIG. 3, the line card 100 includes a packet classifier 110, a traffic limiter 120 and 140, a packet forwarding unit 130, and an output packet processor 150. Here, the packet classification unit 110 and the traffic restriction unit 120 and 140 which are directly related to the present invention will be described in detail. Other packet forwarding unit 130 and the output packet processing unit 150 will be described in the related art. Since the same configuration and operation as the detailed description thereof will be omitted. The traffic limiter will hereinafter refer to the first traffic limiter 120 as an ingress limiter, and the second traffic limiter 140 will hereinafter be referred to as an egress limiter.

The packet classifier 110 classifies the input packets into packets requiring the input rate or output rate limit according to a preset packet classification criterion. Here, the packet classification 110 is classified based on the physical port or packet header information to which the packet is input or output, the classification according to the packet header information is the source / destination IP address, protocol number, source of TCP or UDP Sort by destination port number, VLAN tag, and MPLS label information individually or in combination. By marking an identifier assigned to individual traffic requiring rate limiting for the packet classified by the packet classification unit 110, the classification criteria imposed on the packet and the corresponding processing criteria can be identified later. You can do that. It is assumed that the information contained in the relationship between the classification criteria and the processing criteria and the identifier is set in advance in the system.

The ingress limiting unit 120 includes a monitoring module 121 and a treatment module 122, and the egress limiting unit 140 includes a monitoring module 141.

The monitoring module 121 of the ingress limiter 120 measures the packet input rate for the traffic requiring the input rate restriction output from the packet classifier 110 to determine whether it exceeds the preset bandwidth limit. To judge. In addition, the monitoring module 121 of the ingress limiter 120 may have a buffer therein, and may have a function of mitigating the bandwidth excess by temporarily delaying a packet that exceeds the bandwidth by using the buffer.

The treatment module 122 of the ingress limiting unit 120 discards the excess bandwidth packets that cannot be handled by the monitoring module 121, that is, packets that violate the input rate limit.

 The monitoring module 141 of the egress limiting unit 140 determines whether a limit of a preset bandwidth for a corresponding traffic of a packet having a number or an indication corresponding to an output rate limit is exceeded. In addition, the monitoring module 141 may have a buffer therein, similar to the monitoring module 121 in the ingress limiter 120, and may mitigate the bandwidth exceeding by temporarily delaying a packet that exceeds the bandwidth by using the monitoring module 141. .

A method for controlling a packet input and output from a line card of a packet switching system having such a structure will be described in detail with reference to the accompanying drawings.

The packet classifying unit 110 of the line card 100 classifies the input packets into packets requiring an input rate or an output rate limit according to a preset classification criterion.

The packet classifier 110 outputs the traffic selected by the input rate limit to the monitoring module 121 of the ingress limiter 120, and the traffic that does not need to limit the input rate of the ingress limiter 120. Output to the packet forwarding unit 130 through the treatment module 122. Here, as a result of the classification, there may be a packet that receives both an input rate limit and an output rate limit, and there may be a packet that is not subject to any restriction. In the present invention, only a packet requiring rate limiting will be described, and processing for a packet that is not restricted will be omitted.

As such, after classifying the packet in the packet classifier 110, all traffic requiring rate limiting is output to the ingress limiter 120 without distinguishing the input rate limit and the output rate limit.

First, the operation of the line card in the case of limiting the input rate will be described.

4 is a flowchart illustrating an operation of a line card for input control in a packet switching system according to an embodiment of the present invention.

Referring to FIG. 4, in step 1010, the line card 100 provides traffic to the monitoring module 121 in the ingress restriction unit 120 that requires the input rate restriction classified by the packet classification unit 110. . Then, in operation 1020, the monitoring module 121 in the ingress limiter 120 receives the traffic output from the packet classifier 110 and measures the packet input rate.

In step 1030, the monitoring module 121 determines whether the measured input rate and a preset bandwidth limit, that is, a threshold value, are exceeded. As a result of the determination, if the bandwidth limit is not exceeded, the process proceeds to step 1050 to transmit the packet to the packet forwarding unit 130.

On the other hand, if it is determined in step 1030, if the bandwidth is exceeded, in step 1040, the monitoring module 121 discards all the excess packets as packets that violate the input rate limit. If the bandwidth is exceeded, the excess bandwidth may be temporarily stored in a buffer to delay the packet. However, if an excess bandwidth that cannot be handled by the monitoring module occurs, all excess packets are discarded.

Then, in step 1050, the traffic that passed the input rate limit or the traffic that does not need the input rate limit is transmitted to the packet forwarding unit.

Next, the operation of the line card to limit the output rate will be described.

5A and 5B are flowcharts illustrating an operation of a line card for output control in a packet switching system according to an embodiment of the present invention. For example, the line card will be described as an example of a line card corresponding to a destination of packets transmitted from a line card or an interlocking line card that transmits packets that have passed the input restriction by the operation described with reference to FIG. 4.

5A is a flowchart illustrating an operation of a destination line card, and FIG. 5B is a flowchart illustrating an operation of at least one line card that receives a message transmitted from a destination line card.

Referring to FIG. 5A, in operation 1110, the line card 100 transmits a packet having a number or an indication corresponding to an output restriction from the packet forwarding unit 130 through the monitoring module 141 of the egress restriction unit 140. If the traffic is input, the controller determines whether the traffic exceeds the preset bandwidth limit (threshold value) in step 1120. As a result, when the traffic exceeds the bandwidth, in step 1130, the monitoring module 141 of the egress limiting unit 140 sends the exceeding bandwidth limit notification message to the treatment module 122 of the ingress limiting unit 120 of all line cards. To send). Here, the exceeding bandwidth limit notification message includes information on an identifier of traffic exceeding a limited output bandwidth and an excess rate (% of how much exceeding a prescribed output bandwidth). At this time, the transmission of the notification message exceeding the bandwidth limit, that is, reporting on the traffic exceeding the output rate limit may be made periodically, or may be reported only when the output rate exceeded phenomenon occurs. In addition, instead of specifying and reporting the excess rate separately, a method of reporting only the identifier of the excess traffic when the excess rate is larger than a predetermined value may be applied.

On the other hand, when it is determined in step 1120, if the bandwidth limit is not exceeded, in step 1140, the line card 100 transmits the packet of the traffic generated to the source line card through the output packet processor 150 without output limitation. Thereafter, in step 1150, a result of packet control is received from at least one line card or the source line card that has received the notification of exceeding the bandwidth limit.

In such an operation, the monitoring module 141 in the egress limitation unit 140 may have a buffer therein, and may use the buffer to mitigate the bandwidth excess by temporarily delaying a packet that exceeds the bandwidth. Therefore, in this case, the monitoring module 141 temporarily stores the packet that exceeds the bandwidth and then delays and transmits the packet. However, when traffic exceeding the buffer occurs, the monitoring module 141 transmits the exceeding bandwidth limit notification message.

Then, at least one line card 100 receiving the bandwidth limit exceeding notification message transmitted from the destination line card 100 discards some packets of the output bandwidth exceeded traffic. The operation of the line card 100 will be described with reference to FIG. 5B.

Referring to FIG. 5B, in operation 1210, the line card 100 receives the notification of exceeding the bandwidth limit from the destination line card, and in step 1220, the received bandwidth limit notification message is received by the ingress controller 120. Interpret and identify the identifier and excess rate of traffic beyond the output limit.

In step 1230, the line card 100 randomly randomly selects packets of the identified excess rate among the packets having the identifier of the identified traffic in the ingress controller 120, and then discards the packets selected in step 1240. Thereafter, in step 1250, the result of the packet control is transmitted to the destination line card.

Then, in step 1260, the line card 100 checks whether another bandwidth limit exceeded notification message, that is, an excess phenomenon is reported, and if there is no report for a certain time, ends the operation, and if there is a report, the process proceeds to step 1220 again. Repeat these steps.

In the packet switching system according to the embodiment of the present invention as described above, the line card supports the rate limit function for the traffic of the packet input or output to the packet switch, so that not only the restriction on the specific traffic input but also the specific traffic output By controlling at the input side, it is possible to eliminate unnecessary load on the packet processing device and switching fabric due to packets exceeding the limit.

Therefore, in the present invention, although the output rate limiting traffic is output to one output port, in the case of flowing through a plurality of line cards, the output is discarded at the input stage based on the measurement of the output stage. It can prevent the system from wasting resources. Furthermore, the present invention can impose a fair restriction on excess traffic for each line card since the discarding for excess output rate is made at the same rate for each line card. In other words, by controlling not only the restriction on the specific traffic input but also the specific traffic output, the unnecessary load on the packet processing device and the switching fabric due to the packets exceeding the limit can be eliminated. Equivalent processing of the packet may be made.

As described above, the present invention supports a rate limiting function for specific traffic input or output to the line switch of the packet switching system, thereby preventing the system from wasting resources due to the excess output rate traffic. It has the effect of ensuring fair disposal for

Claims (17)

A packet classification unit for classifying the input packets according to the set I / O traffic limit rate, Controlling the input traffic amount of the classified packets, and controlling the throughput of the corresponding packet when a packet having the same information is input according to output bandwidth exceeding traffic information provided from an output port of at least one line card in a packet switching system. A first traffic limiter, When a packet including identification information necessary for output rate limiting is input from the destination line card, it is determined whether the bandwidth set for the traffic of the input packet is exceeded, and the output bandwidth exceeding traffic information for the traffic exceeding the limited output bandwidth is determined. And a second traffic limiting unit providing the first traffic limiting unit of at least one line card in a packet switching system. The method of claim 1, The packet classification in the packet classification unit is classified according to the physical port that is input or output of the packet or classified according to the header information of the packet. The method of claim 2, The packet classification according to the packet header information may be classified individually or in combination according to source / destination IP address, protocol number, source / destination port number of TCP or UDP, VLAN tag, and MPLS label information. I / O packet control device of card. The method of claim 1, The output bandwidth excess traffic information includes at least one of traffic identifier information and bandwidth excess rate information. The method of claim 1, The second traffic restriction unit, And a buffer for temporarily storing the input packet to mitigate the bandwidth excess and outputting the traffic when the traffic for the input packet temporarily exceeds the set bandwidth. The method of claim 4, wherein And the first traffic limiting unit of the at least one line card discards the packet according to an excess rate exceeding an output bandwidth. The method of claim 6, And a packet discarded by the first traffic limiting unit is randomly selected and discarded. The method of claim 6, Discarding the packet in the first traffic limiting unit, the input and output packet control device of the line card, characterized in that the continuous until the output bandwidth excess traffic information is not received in the second traffic limiting unit of at least one or more line card . The method of claim 8, The output bandwidth exceeding traffic information from the second traffic limiting unit of the at least one line card to the first traffic limiting unit of the at least one line card is provided only at a set period or when an output bandwidth exceeding phenomenon occurs. Input / output packet control device for line card. An input / output packet control method in a packet switching system having at least one line card, Classifying packets input to the line card according to the set I / O traffic limit, Controlling the amount of input traffic of the classified packets to be transmitted to a destination line card; When a packet including identification information necessary for output rate limitation is input from the destination line card, the output bandwidth exceeding traffic information for the traffic exceeding the limited output bandwidth is determined by determining whether the bandwidth set for the traffic of the input packet is exceeded. Providing at least one line card in a packet switching system, And controlling a traffic amount of a corresponding packet when a packet having the same information is input according to output bandwidth exceeding traffic information provided from an output port of at least one line card in the packet switching system. I / O packet control method in. The method of claim 10, wherein the classifying the packets input to the line card comprises: I / O packet control method in a packet switching system characterized in that the classification according to the physical port to the input or output of the packet or the header information of the packet. The method of claim 11, The packet classification according to the packet header information is classified according to source or destination IP address, protocol number, source / destination port number of TCP or UDP, VLAN tag, and MPLS label information individually or in combination. I / O packet control method in switched system. The method of claim 10, The output bandwidth excess traffic information includes at least one of traffic identifier information and bandwidth excess rate information. The method of claim 10, In the step of providing the output bandwidth excess traffic information to at least one or more line card in the packet switching system, if the traffic for the input packet temporarily exceeds the set bandwidth, it is temporarily stored in a buffer to mitigate the bandwidth excess And outputting a post-output packet. The method of claim 13, The controlling of the traffic volume of the corresponding packet includes discarding the corresponding packet according to an excess rate exceeding an output bandwidth. The method of claim 15, The discarded packet is randomly selected and continuously discarded until output bandwidth excess traffic information is not received from the output port of at least one or more line cards. The method of claim 16, The output bandwidth excess traffic information provided from the output port of the at least one line card is provided in a set period or only when the output bandwidth excess phenomenon occurs, characterized in that the I / O packet control method in a packet switching system.

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