KR100739492B1 - Quality of service management device for ip network and method thereof - Google Patents

Abstract

The present invention relates to an apparatus and method for managing quality of service in an IP network.

In the apparatus for controlling a quality of service, the input buffer temporarily stores data packets input from the IP network. The quality of service manager classifies the data packet received from the input buffer for each flow and controls the output of the data packet for each flow. The output queue schedules and transmits the data packet received from the service quality management unit.

Flow classification, quality of service management

Description

QUALITY OF SERVICE MANAGEMENT DEVICE FOR IP NETWORK AND METHOD THEREOF

1 is a block diagram illustrating a service quality management apparatus according to a first embodiment of the present invention.

2 is a schematic diagram showing packet processing in a bandwidth controller of a service quality management apparatus according to a first embodiment of the present invention.

3A is a schematic diagram illustrating a latency control process in a rate control unit of a service quality management apparatus according to a first embodiment of the present invention.

3B is a schematic diagram illustrating a continuity control process in a rate controller of the apparatus for controlling quality of service according to the first embodiment of the present invention.

4 is a schematic diagram showing packet processing in a WRED control unit of a service quality management apparatus according to a first embodiment of the present invention.

5 is a block diagram illustrating a service quality management apparatus according to a second embodiment of the present invention.

6 is a block diagram illustrating a service quality management apparatus according to a third embodiment of the present invention.

7 is a flowchart illustrating a method for managing quality of service for each flow according to a first embodiment of the present invention.

The present invention relates to an apparatus and method for controlling service quality in an IP (internet protocol) network.

In the existing asynchronous transfer mode (ATM) network, the quality of service can be collectively managed between the receiving end and the transmitting end. Although communication resources can be used efficiently in an IP network, transmission capacity is not exclusively assigned to each communication resource. Therefore, when the traffic of users increases, packets are queued in the transmission process, causing a long time delay. .

Currently, the IP network is neutral to all applications and all traffic is treated equally in the IP network, so it is difficult to give priority to the characteristics of the generated traffic. In particular, if the preceding traffic monopolizes bandwidth, the processing of important data is delayed. Therefore, the dependence on the network or the location of providing customer service through the network greatly decreases the overall work efficiency. . In order to solve this problem, there is a growing interest in introducing a quality of service (QoS) technique that can allocate an appropriate bandwidth to important data or traffic and ensure priority processing.

In ATM network, even if a certain length of cell is transmitted and it goes through several network equipments, it is possible to continuously monitor the network state through OAM (Operation, Administration and Maintenance) cell or control cell. Uniform quality of service management can be achieved. An expensive network processor or software method is used in the IP network in order to obtain the same efficiency as the service quality management performed in the ATM network.

In particular, since there is no dedicated hardware capable of providing high quality services, a software processing scheme mainly through a CPU is currently used. However, due to the limitation of the CPU capacity, the transmission speed of the data packet cannot be guaranteed. As a result, not only a perfect level of service quality management is performed but also the same level of service quality as that of an ATM network in an IP network is required. Expensive network processor equipment has to be used, but service quality management through such a method raises the cost of the system. Therefore, there is a problem of requiring dedicated hardware for this purpose.

An object of the present invention is to provide an apparatus and method for managing a quality of service capable of guaranteeing a different quality of service for each user in an IP network.

Another technical problem to be achieved by the present invention is to provide a service quality management apparatus and method for ensuring the priority or quality of services according to the type of service.

In order to solve this problem, according to an aspect of the present invention, an input buffer for temporarily storing data packets input from an IP network, data packets received from the input buffer are classified for each flow, and A service quality management apparatus in an IP network including a service quality control unit for controlling an output and an output queue for scheduling and transmitting a data packet received from the service quality management unit.

The service quality management unit may include a flow classification unit classifying a flow of data packets received from the input buffer, at least one first control unit configured to pass, warn, and discard data packets for each of the flows, and the output queue. At least one second control unit for controlling the output of the data packet by discarding the data packet received from the first control unit according to the state. The first control unit may include at least one of a bandwidth control unit or a rate control unit. When the input data packet should be discarded, the second control unit may preferentially discard the data packets marked with the warning to control the output.

According to another feature of the present invention, the received data packet is classified according to flow, the passing, warning display, discard setting of the data packet for each flow, and the warning displayed according to the state of the output queue selected for each flow. Provided is a method for controlling quality of service in an IP network, the method comprising controlling the output of a data packet by first discarding the packet.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification. In addition, when a part is said to "include" a certain component, this means that it may further include other components, except to exclude other components unless otherwise stated.

1 is a block diagram illustrating a service quality management apparatus according to a first embodiment of the present invention. As shown in FIG. 1, the apparatus 100 for controlling quality of service in an IP network according to the first embodiment of the present invention includes an input buffer 110, a service quality managing unit 120, an internal memory unit 130, and an output queue. 140.

The input buffer 110 temporarily stores the data packet input from the transmitter to serve as a buffer while the service quality management unit 120 processes the data packet.

The service quality management unit 120 classifies the flow with reference to the header information of the received data packet, and performs control suitable for the quality of service required for each flow with reference to the internal memory unit 130.

The internal memory unit 130 stores data tables necessary for data packet processing in the service quality management unit 120 and provides the stored information to the service quality management unit 120 under the control of the service quality management unit 120 or an external CPU. do. The internal memory 130 may store a quality of service table (QoS table), a weighted random early detection table (WRED) table, and the like, to which a predetermined service quality is matched for each flow.

The output queue 140 stores the data packets output through the packet flow control in the service quality management unit 120 in the form of a virtual output queue and outputs the data packets according to the scheduling order for each queue according to the scheduling algorithm.

Hereinafter, the service quality management unit 120 according to the first embodiment of the present invention will be described in detail with reference to FIGS. 1 to 4. As shown in FIG. 1, the first control unit of the service quality management unit 120 according to the first embodiment of the present invention includes a bandwidth control unit 122 and a rate control unit 123, and the second control unit includes a WRED control unit ( 124).

First, the flow classification unit 121 analyzes the header information of the data packet received by the service quality management unit 120 to determine the flow characteristic. The header information may include a MAC address, an IP address, or a port number, and the flow classifier 121 classifies packet flows by MAC addresses included in the header information, classifies packet flows by IP addresses, or port numbers. Classify the packet flow using. Through this flow classification process, different service quality can be guaranteed for each user in data transmission in the IP network, and even the same user can be guaranteed a differentiated service quality according to the type of service actually used.

When the flow characteristic is determined by the flow classifying unit 121, the bandwidth controller 122, the rate control unit 123, and the WRED control unit 124 of the subsequent stage are pre-matched and stored in the internal memory unit 130 according to the flow characteristic. Reference to these controls the transmission of subsequent data packets for each flow. In the embodiment of the present invention, the MAC address, the IP address, or the port number has been described as being used for flow determination, but various header information such as an IP protocol type and destination TCP / UDP port information may be used.

Next, the bandwidth controller 122 and the rate controller 123 determine a packet to pass, a packet to discard, and a packet to drop marking according to the quality of service set for each flow. That is, a packet that satisfies the condition required for the quality of service set for each flow is passed without other processing, and a packet that does not satisfy the condition required for the quality of service is passed after being discarded or warned. At this time, the alerted packet may be preferentially discarded by the WRED controller 124 according to the condition of the output queue 140.

FIG. 2 is a schematic diagram illustrating a range of packets passing, warning, and discarded among data packets input per unit time to the bandwidth controller 122, and FIGS. 3A and 3B are packets input to the rate controller 123, respectively. FIG. 3 is a diagram illustrating a latency control method and a continuity control method for determining packets to be passed or warning by using the intervals between them as control variables. 4 is a diagram illustrating a process in which the WRED control unit 124 discards the packets that have been warned by the bandwidth control unit 122 and the rate control unit 123 according to the state of the output queue 140.

The bandwidth controller 122 performs data packet control for each flow based on the guaranteed bandwidth and the maximum bandwidth information. At this time, the guaranteed bandwidth and the maximum bandwidth may be stored in the QoS table of the internal memory unit 130 for each flow. Here, the guaranteed bandwidth refers to a bandwidth that can accommodate packets input within a unit time without additional processing, and the maximum bandwidth means a bandwidth defined to discard incoming packets exceeding this within a unit time.

As shown in FIG. 2, the bandwidth controller 122 passes all the input data packets when the cumulative bandwidth plus the total length of the data packets input up to a specific point in time does not exceed the guaranteed bandwidth Sus_bw. If the cumulative bandwidth exceeds the maximum bandwidth Max_BW, the data packet inputted after the time point exceeding the maximum bandwidth Max_BW is discarded. When the cumulative bandwidth exceeds the guaranteed bandwidth Su_BW but does not exceed the maximum bandwidth Max_BW, the bandwidth controller 122 drops the corresponding data packets and then drops the marking. To send. Here, the warning mark is a mark indicating that the object to be discarded preferentially in the subsequent processing.

However, when the characteristic of the flow determined by the flow classifying unit 121 is a real-time service having a characteristic in which the quality of service is sharply degraded due to the discarding of the packet, the bandwidth controller 122 determines that the accumulated amount of data packets is the maximum bandwidth. Even if it exceeds (Max_BW), it can transmit to the rate control unit 123 without discarding the data packet.

As shown in FIGS. 3A and 3B, the rate controller 123 identifies the interval between the packet and the packet, and warns the packet that falls outside the allowable range of the preset packet interval for each flow to the WRED controller 124. send. The rate control unit 123 processes the data packet according to the input rate of the data packet flow in one of latency control and burst control. The rate controller 123 manages the quality of service by using four types of parameters, CT, BT, ET, and GT, which are preset for each flow and stored in the internal memory 130. CT represents a control type. As shown in FIG. 3A, the latency control is performed when CT is 0, and packet control is performed through continuity control when CT is 1 as shown in FIG. 3B. ET denotes the expected arrival time of the trailing packet, BT denotes the maximum transmission delay allowance from the ET, and GT denotes the input time difference between the preceding data packet and the trailing data packet.

Latency control (when CT = 0) is a rate control scheme when the interval between data packets is too long. As shown in FIG. 3A, in latency control, a range obtained by adding BT to ET calculated in consideration of the interval between preset packets is set as an allowable range (ET + BT) for the packet interval. After the preceding data packet is input, the following data packet passes and passes to the WRED controller 124. However, the rate control unit 123 displays a warning (DROP) for the following data packet input at a time elapsed beyond the allowable range (ET + BT) and transmits it to the WRED control unit 124. The hatched area shown in the lower part of FIG. 3A indicates a time range in which data packets which are displayed as warning because they do not satisfy the allowable range are input.

The continuity control (CT = 1) is a rate control method when the interval between data packets is too short. When the input of the packet flow is instantaneously congested and the input rate of the packets is too high, the appropriate level required for each flow is required. This is to prevent service quality management from being performed. As shown in FIG. 3B, in contrast to the case of latency control, a time interval in which the time domain is subtracted from BT from the ET calculated in consideration of the interval between the preset packets according to a condition required to satisfy the service quality. It is set to the allowable range for ET-BT. That is, if the time GT before the subsequent data packet is input after the preceding data packet is input is within the allowable range (ET-BT) or exceeds the ET, the trailing data packet is passed as it is and the WRED controller ( 124). However, the rate control unit 123 displays a warning (DROP) for the following data packet input in a time domain shorter than the allowable range (ET-BT) and transmits it to the WRED control unit 124. The hatched area shown in the lower part of FIG. 3B indicates a time range in which data packets that are not displayed within the allowable range and are displayed as warnings are input.

The WRED control unit 124 monitors the state of the output queue 140 to control the transmission of data packets to the output queue 140. That is, the WRED control unit 124 transmits data packets by selecting a queue corresponding to the priority of which the quality of service can be managed at a level suitable for the flow characteristic among the plurality of prioritized queues. At this time, by reading the amount of data packets accumulated in the queue from the register that recorded the information of the queue, the status of the queue is read, and the output queue 140 is referred to by referring to the WRED table stored in the internal memory unit 130. Control the amount of data packets sent. The WRED control unit 124 uses an EP (early point), an MP (max point) and a slope set for a specific cue as control parameters.

As shown in FIG. 4, when the amount of data packets accumulated in the output queue 140 does not exceed EP, all data packets input to the WRED controller 124 are transmitted to the output queue 140 and the MP is transmitted. If exceeds, all subsequent packets are discarded. On the other hand, from the moment when the amount of data packets transmitted and accumulated in the output queue exceeds the EP, the packets at the ratio of the discard rate preset for each flow are preferentially given to the data packets that are warned by the bandwidth controller 122 and the rate controller 123. Discard it.

At this time, if the warning packet is not marked on the discarded data packet, the packet is transmitted to the output queue, and the data packet marked with the warning signal input at the closest time thereafter is discarded instead of the packet without the warning mark previously output. . However, for a data packet flow having a characteristic that the quality of service is drastically degraded due to the discarding of the packet, when the queue selected by the WRED control unit 124 cannot accept any more data packets, Change the priority to send data packets to a less congested queue.

Through such a configuration, the IP network manages and guarantees the quality of service according to each flow, ensuring that no time delay or packet loss occurs in the transmission of multimedia data such as IPTV / VoIP, and requiring emergency such as security or fire on the home network. To process the data first.

In the first embodiment of the present invention, the data packet is discarded or warned by the bandwidth control and the rate control before the packet is delivered to the WRED controller 124. However, the present invention is not limited thereto. That is, the order of bandwidth control and rate control may be changed, and other control methods may be used in addition to bandwidth control and rate control, which may set pass, warning, and discard conditions according to the quality of service.

5 is a block diagram illustrating an apparatus for managing quality of service in an IP network according to a second embodiment of the present invention. As shown in FIG. 5, the quality of service management unit in the IP network according to the second embodiment of the present invention has the same structure as the first embodiment except that the network address translation unit 125 is added. In this case, the internal memory unit 130 may additionally include data tables for network address translation.

The internal memory unit according to the second embodiment of the present invention may include a network information translation (NAT) information table and a network translation table (NAT translation table).

The network address conversion unit 125 determines whether the transmitting end of the data packet is internal or external from the network address translation reference step and converts the network address by referring to the internal memory unit 130.

In other words, when the packet transmitting end is a port inside the reference end, the internal port number is used to look up from the data table and converted into a predefined external port number corresponding to the source port number. Similarly, if the packet transmitting end is an internal IP address, the packet is converted into a predefined representative IP address. If the packet transmitting end is determined to be an internal MAC address, the packet is converted into a predefined external MAC address. Convert to the MAC address of the external switch.

In addition, when the packet transmission end is a port outside the reference end, it looks up from the data table using the external port number and converts it into a predefined internal port number corresponding to the destination port. At this time, since the internal port number corresponds to the internal IP address, the destination IP address and the destination MAC address are converted with reference to the internal memory unit 130, and the external IP address is converted into the internal MAC address of the service quality management apparatus. Convert. Since the header part of the input data packet is changed through this series of processes, the checksum included in the header part is also recalculated and recorded.

Through this configuration, the security effect of preventing the IP address of the internal network using the quality of service management device from being exposed to the external network can be achieved, and the IP shortage problem can be solved by dividing the internal network by port number using only one representative IP address. It can be solved.

6 is a block diagram illustrating an apparatus for managing quality of service in an IP network according to a third embodiment of the present invention. The service quality management unit in the IP network according to the third embodiment of the present invention has the same structure as the first embodiment except that the charging control unit 126 is added.

The charging controller 126 counts the data packets output to the output queue 140 by a predetermined time unit without being discarded in the control process by the bandwidth controller 122, the rate controller 123, and the WRED controller 124 for each flow. Perform billing for service use.

7 is a flowchart illustrating a service quality management method in an apparatus for managing quality of service in an IP network according to a first embodiment of the present invention.

First, the input buffer 110 receives the data packets through the IP network and transfers them to the flow classifier 121 (S810). The amount of data packets that can be processed by the quality of service management unit 120 may be transmitted through buffering in the input buffer 110 for the input data packet flow.

The flow classifying unit 121 analyzes the header of the received data packet to determine the characteristics of the flow, and classifies the data packet for each flow (S820). At this time, according to the flow classification result, the parameters used for the subsequent processing of the data packet are set to manage the quality of service. The parameters set here control four types of parameters, CT, BT, ET, and GT, which control the packet interval in the packet flow, and control the data packet transmitted to the output queue to ensure proper quality of service according to the characteristics of the flow. Parameters for the early point (EP) and the maximum point (MP) and slope (slope) may be included. Through this process, the data packet can arrive at the destination while guaranteeing the service of the reserved level for each flow.

The bandwidth controller 122 determines whether the amount of data packets input and accumulated in a unit time exceeds a guaranteed bandwidth, which is a limited bandwidth capable of accommodating a preset data packet, so that the accumulated bandwidth exceeds the guaranteed bandwidth. If it is determined not to pass the data packet as it is input without any other processing (S830). In this case, a process of network address translation in the network address translation unit 125 may be added before the bandwidth control process for security.

If it is determined that the cumulative bandwidth of the data packet input per unit time exceeds not only the guaranteed bandwidth but also the maximum bandwidth (S831), then all data packets input thereafter are discarded (S862). However, if the data packet flow has the characteristics of a real-time service, the data packet input exceeding the maximum bandwidth is also passed without discarding in order to prevent degradation of service quality. On the other hand, if the cumulative bandwidth has a value between the guaranteed bandwidth and the maximum bandwidth, the data packet inputted in this time domain is not discarded but is displayed as a warning and passed (S832).

The rate control unit 123 receives the packets passing through the bandwidth control unit 122 and the packets marked with the warning as they are input without any processing, and determines the interval between the packets. If the interval between the data packets does not go out of the preset packet interval allowance according to the flow characteristics (S840), passes through the packets as it is, if the deviation is out of the allowable range after passing a warning mark to the following data packet ( S841).

The WRED control unit 124 monitors the state of the output queue 140, which is given priority for each data packet for each flow, to determine the occupancy rate of the device output port, and outputs the data packets according to the determination result. 140) or discard. If the amount of data packets accumulated in the output queue 140 does not exceed EP, which is a preset threshold value for each queue, the data packets are transmitted to the output queue as they are (S850). However, if it exceeds the EP, it is determined whether the amount of the accumulated packet exceeds the MP, and if it exceeds, discards all data packets subsequently input (S851, S862), and the amount of the accumulated packet exceeds the MP. If not, it is possible to guarantee a predetermined level of quality of service for each flow by adjusting the amount of output data packets by discarding subsequent warning-marked data packets that are input later (S851 and S861). In this case, the charging control unit 126 may count the amount of packets that are output without being discarded and used for the service for a predetermined time and may be used as a reference for charging the service user.

The apparatus for controlling a quality of service according to an embodiment of the present invention described above may be implemented in hardware in a communication chip implemented in a high speed chip form, for example, in the form of a very large scale integration (VLSI) or an application-specific integrated circuit (ASIC). It can be implemented as.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

As described above, according to the exemplary embodiment of the present invention, since a series of service quality management processes are all performed based on flows, precise service quality management of packets or bytes may be performed for each flow. In addition, by performing network address translation together in the service quality control device, information such as the user's IP address is not exposed to the outside, and even the same user can guarantee the priority or quality of the service according to the type of service actually used. have.

Claims (20)

delete An input buffer for temporarily storing data packets input from an IP (internet protocol) network; A service quality management unit classifying the data packet received from the input buffer for each flow and controlling the output of the data packet for each flow; And Output queue for scheduling and transmitting the data packet received from the service quality management unit Including; The service quality management unit, A flow classification unit for classifying data packets received from the input buffer for each flow; For each flow, passing the data packet when the cumulative bandwidth for the data packet is smaller than the first bandwidth, discarding the data packet when the cumulative bandwidth is larger than the second bandwidth, and the cumulative bandwidth is the first bandwidth. At least one first control unit including a bandwidth control unit configured to perform a warning display process on the data packet when it is between a first bandwidth and the second bandwidth; And A second control unit for controlling output of the data packet by determining whether to discard the warning display processed data packet received from the first control unit according to the state of the output queue; Quality of service device comprising a. The method of claim 2, The bandwidth control unit determines the cumulative bandwidth by the amount of data packets input per unit time. delete The method of claim 2, The at least one first control unit, And a rate control unit for controlling an output of the data packet by determining an interval between successive input data packets. The method according to any one of claims 2, 3 or 5, The first bandwidth is the lowest bandwidth that is preset for each flow, And the second bandwidth is a maximum bandwidth preset for each flow. The method of claim 5, The rate control unit, And a warning display process for a subsequent data packet input at a time point outside a preset allowable range for each flow for a preceding data packet. The method of claim 7, wherein And the rate control unit sets an area between an expected time of arrival of the following data packet and a time point at which the maximum transmission time is added to the expected time of arrival as the allowable range. The method of claim 7, wherein And the rate control unit sets an area between the estimated time of arrival of the following data packet and the time of subtracting the maximum allowable transmission time from the estimated time of arrival as the allowable range. The method according to any one of claims 2, 3 or 5, The flow classification unit classifies a flow by analyzing a header of the received data packet. The method according to any one of claims 2, 3 or 5, The second control unit includes a weighted random early detection (WRED) control unit that discards the first displayed warning data packet when the amount of data packets accumulated in the output queue exceeds a preset threshold. Device. The method according to any one of claims 2, 3 or 5, The service quality management unit further comprises a network address translation unit for analyzing the header of the data packet inputted to translate the network address of the data packet input terminal. The method according to any one of claims 2, 3 or 5, The service quality management unit further comprises a charging control unit for performing a charge for the user by counting the data packet transmitted to the output queue for a predetermined period of time. The method according to any one of claims 2, 3 or 5, And an internal memory unit configured to store at least one data table for flow classification of the data packet and output control of the data packet. In the service quality management method for providing differentiated service quality for each data packet flow input from the IP network, Classifying the received data packet by flow; For each flow, passing the data packet when the cumulative bandwidth for the data packet is smaller than the first bandwidth, discarding the data packet when the cumulative bandwidth is larger than the second bandwidth, and the cumulative bandwidth is the first bandwidth. Alerting the data packet when it is between a first bandwidth and the second bandwidth; And And controlling the output of the data packet by first discarding the alerted packet according to the state of the output queue selected for each flow. The method of claim 15, The cumulative bandwidth is determined by the data packet input per unit time, And the first bandwidth is a minimum bandwidth preset for each flow, and the second bandwidth is a maximum bandwidth preset for each flow. The method of claim 15, And displaying a warning mark on the trailing data packet input at a time when the interval between the data packets is out of a predetermined allowable range. The method according to any one of claims 15 to 17, Controlling the output of the data packet, And when the amount of data packets accumulated in the output queue exceeds a preset threshold and subsequently discards the data packet to be input, discarding the first displayed alerted data packet. The method of claim 15, And analyzing a header of the received data packet to translate a network address of the data packet input terminal. The method of claim 15, After controlling the output of the data packet, And counting the data packets outputted without being discarded for a predetermined period of time.

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