KR100265068B1 - Real-time traffic monitoring and control method in asynchronous transmission mode switching node - Google Patents

Abstract

PURPOSE: A method for monitoring and controlling a real-time traffic in a switching node of an ATM(Asynchronous Transfer Mode) is provided to correctly decide the observance of a traffic parameter negotiated in the setup of cell connection, and to enable efficient usage of a network resource by statistical multiplexing of a data cell. CONSTITUTION: A VPI/VCI(Virtual Path Identifier/Virtual Channel Identifier) field and a CLP(Cell Loss Priority) are extracted from a 5-byte cell header of a 53-byte ATM(Asynchronous Transfer Mode) cell. A cell header effective value of a look-up table(20) for the extracted VPI/VCI field is checked, to decide the effectiveness of a received cell. If the received cell is an effective cell, monitoring information and control information are compared, to check whether a traffic parameter is violated. If violated, whether a present user connection violates a negotiation parameter is checked using a traffic control information value and a CLP field value in the look-up table(20). The cell is compressed/tagged/discarded, according to the violation of the negotiation parameter. A cell control result decided for the effective call is delivered to a physical layer performing actual cell processing. Cell monitoring information is reported to an upper control tablet, and cell control information is reset on the basis of the cell monitoring information.

Description

Real-time traffic monitoring and control method in asynchronous transmission mode switching node

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a traffic monitoring and control technique that must be preceded for traffic management in an Asynchronous Transfer Mode (ATM) switching node, and in particular, to monitor and control ATM traffic in real time. The present invention relates to a real time traffic monitoring and control method in an ATM switching node.

Traffic entering the ATM network has various bandwidth requirements and burst characteristics, and an excellent traffic control method and bandwidth management method to efficiently use network resources and to provide quality of service (QOS) required by users. This is necessary.

On the other hand, the traffic source of the ATM network can use the network resources beyond the traffic negotiation parameters if there is no traffic monitoring and control function in the switch node. Therefore, if the traffic management and control function does not operate correctly due to the fluctuation of the traffic input into the network, the ATM network may be congested due to the occurrence of VBR (Variable Bit Rate) traffic and operate properly. There is a high probability of not losing. Accordingly, the ATM Forum recommended the Generic Cell Rate Algorithm (GCRA) to control ATM traffic. The GCRA is known as 'Virtual Scheduling Algorithm' or 'Continuous-state Leaky Bucket Algorithm', and has been proposed to control peak cell rate, cell delay variation, average cell rate and burst tolerance. In both of the above schemes, the data cell rate input to the switch is controlled by using the buffer limit and the increment value of the counter determined for each traffic. The GCRA is a simple and high performance algorithm for investigating whether a user cell's negotiation parameter is violated, but there is no reason to use the algorithm as a UPC (Usage Parameter Control) method when designing a switch. That is, if QOS support of a call that transmits a cell in compliance with a negotiation parameter is possible, no problem arises with any UPC algorithm.

Originally, the GCRA is an algorithm for controlling the cells by investigating whether the user cell is in violation of the negotiation parameter as described above, and no standard is specified for other functions. However, as a system designer, there is no function to monitor the arrival rate of the cell except for the GCRA, so that a slight change is made to monitor the user traffic flowing into the switching node and use it to measure the bandwidth utilization of all user calls. There is also a trend. Regardless of which ATM service is currently defined, the traffic flowing through the network must be monitored for cell rate control, QOS guarantees, and network performance. By operating the GCRA and resource management (RM) cell for feedback control, it is possible to investigate the load state of traffic in the network, but these algorithms are VBR (Variable Bit Rate) since the primary purpose is not to monitor traffic. Accurate monitoring of traffic is not possible.

When the above-mentioned prior art is used as a monitoring and control technique for ATM traffic having various characteristics, the following problems occur.

First, at least two counters (one for controlling the highest cell rate and one for controlling the average cell rate) are required to monitor and control one variable bit rate (VBR) virtual connection.

Second, in network resource management allocated to VBR (Variable Bit Rate) and ABR (Available Bit Rate) services, a buffer size and leaky rate pairs such as the number of connections must be installed. Managing resources collectively becomes very difficult.

Third, the control algorithm for the data cell to be transmitted is executed only at a preset measurement time interval, so that it is impossible to measure the actual average cell rate. In other words, the accuracy of GCRA cell rate control depends on the size of the Leaky Bucket.

Fourth, the traffic flowing into the switching node can be controlled by setting the leaky rate, but it is impossible to calculate the real-time resource utilization rate of all VCs. Also, the leaky rate for a particular connection means that a fixed bandwidth is allocated to that connection in succession, so it is difficult to expect optimal resource usage efficiency.

Fifth, when the burst characteristic of information increases, the hardware burden increases because the buffer size in the switch must be increased. Therefore, in order to support the traffic having such a burst characteristic, it is preferable to adopt the same method as the conventional FRP (Fast Reservation Protocol), but the FRP does not provide the monitoring and reporting function of the traffic, and the input data cell is buffered once. The processing delay always occurs because it is processed and then transmitted.

Sixth, although congestion control is essential in ATM networks, there is a limitation in the congestion control mechanism applicable because of the delay characteristics of the fast channel itself. In other words, in the current congestion control mechanism, when checking the congestion status of the network, the network is checked by checking the share of buffers in each switch, or otherwise measuring a round trip time (RTT) by sending a special management cell to the network link. Although congestion is detected, these conventional methods do not directly detect congestion in real time. As a result, it becomes difficult to solve the problem of overhead caused from processing delays and propagation delays of cells in each switch.

To summarize the above conventional problems;

In the conventional traffic control algorithm, it is very difficult to optimally achieve statistical multiple effects, which is the greatest advantage of ATM networks, without solving the above-described disadvantages. Moreover, even if there is room in network resources, it often happens that it affects the QOS of the established connection. The fundamental reasons for this problem are that most of the traffic control algorithms are not running in real time, and that each function of traffic management operates independently.

Accordingly, an object of the present invention is to implement a traffic monitoring and control algorithm that manages ATM traffic in real time in order to solve the above problems, to guarantee the quality of service required by the user in the ATM switching node to maximize the performance of the ATM network. To provide a real-time traffic monitoring and control method of.

In order to achieve the above object, the present invention provides a method for monitoring and controlling traffic in real time in an asynchronous transmission mode switching node, wherein when an ATM cell is received, a cell header of 5 bytes is inspected to generate a current connection from a user connection in which the current cell is duly established. Checks whether the current cell is a valid cell, compares the monitoring information with the control information, checks whether the currently set traffic parameter is violated, and discards the corresponding cell by the cell loss priority field value when it is determined to be a violation. Or tagging, sending a cell control result determined for the valid cell to a physical layer, reporting cell monitoring information to an upper control plane, and resetting cell control information based on the cell monitoring information. It is characterized by.

1 is a block diagram of an ATM cell control block for performing real-time traffic monitoring and control according to the present invention

2 is a control flowchart for monitoring and controlling ATM traffic in real time according to the present invention.

3 is a block diagram of a typical ATM cell header

4 is an exemplary diagram for illustrating determination of a cell monitoring counter size according to the present invention.

5 is an exemplary diagram for showing use of cell monitoring information and cell control information according to the present invention.

6 is a flowchart of an algorithm for real-time cell monitoring and control according to an embodiment of the present invention.

7 is an exemplary diagram for checking whether a cell is violated using a CDV according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention, such as specific processing flows. It will be apparent to those skilled in the art that the present invention may be practiced without these specific details. Detailed descriptions of well-known functions and configurations that are determined to unnecessarily obscure the subject matter of the present invention will be omitted.

1 is a block diagram of an ATM cell control block for performing real-time traffic monitoring and control according to the present invention, ACCB (ATM Cell Control Block) 10 is HDPU (Header Data Processing Unit) 13, CADU (Control Action Determination Unit) 15, TMP (Traffic Monitor Part) 17, MIRU (Monitor Information Reporting Unit) 19, and is connected to the look-up table 20, MDPP (Monitor Data Processing Part) 30 . The operation and role of each of these components will be described.

The ATM Cell Control Block (ACCB) 10 measures the time between two adjacent cells by a counter on the ATM layer and reports the time to the Monitor Data Processing Part (MDPP) 30.

The header data processing unit (HDPU) 13 receives a 5-byte cell header from a PHYSICAL LAYER (P / L) to transmit a Virtual Path Identifier (VPI) / Virtual Channel Identifier (VCI). The virtual channel identifier, hereinafter referred to as VCI) and CLP (Cell Loss Priority) header information are applied to the CADU 15, and the counter driving signal based on the cell clock is applied to the TMP 17.

CADU (Control Action Determination Unit) 15 transmits the VPI / VCI value among the header information input from the HDPU 13 to the look-up table 20, and determines the control information Cc value in the look-up table 20 and the TMP 17. The monitoring information Cm value is compared and the comparison result is applied to MIRU 19. The cell processing is controlled by giving a control signal such as a DISCARD signal and a TAG signal according to the comparison result to the data cell buffer of the P / L.

The MIRU (Monitor Information Reporting Unit) 19 receives the control result of the CADU 15 as a logic unit and reports the monitoring information Cm to the control plate. When the control result is above a specific control range, the MIRU 19 reports the MDPP 30. The control information Cc is updated.

In the look-up table 20, a match flag value, control information Cc, a negotiation parameter violation criterion A_I bit, and CNS value, which are validity determination criteria of a cell according to VPI / VCI, are designated.

2 is a control flowchart for monitoring and controlling ATM traffic in real time according to the present invention.

When the cell is received in step 101, the ATM Cell Control Block (ACCB) 10 receives the VPI / VCI and Cell Loss Priority (CLP) from the 5-byte header of the received 53-byte (BYTE) ATM cell. Extract the field. A general configuration of the 5 byte (BYTE) ATM cell header is shown in FIG. Thereafter, in step 103, it is determined whether a cell is valid using a match flag value of a look-up table. This is to determine whether the current cell is a valid cell generated from a connection that is legitimately connected with reference to the Match flag value in the look-up table. For example, the validity of the cell is determined to be valid if Match flag = 1 of the extracted VPI / VCI field, and invalid if Match flag ≠ 1, thereby discarding the cell. In step 103, if the cell is valid, in step 105, the monitoring information Cm is compared with the control information Cc to check whether the traffic parameter is violated. In this step, in order to cope with the concentration effect of the cell, a cell delay variation (CVV) value predetermined during connection establishment is used. In more detail with reference to FIG. 7, if the monitoring information Cm (Cm2 or Cm3 in FIG. 7) is within the allowable cell delay variation range of the CDV value specified before and after the control information Cc, which is a reference time value, the received cell is allowed. If Cm1 is determined to be a violation, in case of Cm4, the cell is allowed and the next control information Cc is set to the value of Cm4. In step 107, the A_I (Active_Idle) bit, which is traffic control information, is used to determine whether the current user connection is actually in violation of the negotiation parameter, and access control of an unused band is performed. For example, if A_I = 1, a violation is determined, and if A_I = 0, a cell is suppressed. If it is determined that the violation is determined by the determination, the cell is discarded or tagged by the CLP field value. As described above, the cell control result determined for the effective cell is actually sent to the physical layer (P / L) where the processing for the cell is performed, and the cell monitoring information Cm is reported to the upper control plane. Several rules can be considered as a method of reporting the monitoring information Cm. That is, it is ideal to report every time when the monitoring information Cm and the control information Cc do not coincide, but in this case, a considerable load is placed on the system, so only when the difference between the monitoring information Cm and the control information Cc exceeds the cell delay variation allowable CDV. It is desirable to report. In addition, the reporting time may be periodically performed. In this case, the optimal reporting time interval is a parameter that is determined based on the traffic characteristics and the calculator's ability to manage traffic. Finally, the cell counter is reset and the above process is repeated for the next data cell.

Hereinafter, functional requirements applied to the present invention will be described item by item.

1. Receiving function of ATM cell header

In addition to the cell clock, which is a system synchronization signal, a 5-byte cell header synchronized with the byte clock immediately after the cell clock is received. The cell clock is used to drive a binary counter for monitoring each cell. On the other hand, the received cell header is again separated or synthesized for each field and used to monitor and control user data cells.

2. Validation function of ATM cell header

Examine the cell header to determine whether the current cell is from a legitimately connected user connection. It transmits 8 bits of VPI extracted from cell header (12 bits for NNI and 16 bits) and 16 bits of VCI to look-up table. It executes by receiving the corresponding match flag signal.

3. Monitoring function of input cell

All data cells originating from VBR (Variable Bit Rate) traffic sources are monitored by a binary counter of a specific bit. The size of the binary counter is variably adjusted according to the characteristics of traffic to be serviced during system operation. For example, a 14-bit binary counter is for monitoring up to 16 kbps of low-speed data cells. That is, in the case of 16 kbps traffic, when the link speed is 155.52 Mbps and the cell rate from the traffic source is Rc, the arrival interval Ticat between adjacent cells is calculated by Equation 1 below.

T _icat = line speed ÷ Rc

Calculating arrival intervals between adjacent cells in case of 16kbps traffic according to Equation 1 above; T _icat = (155.52 × 10 ⁶ ) ÷ (16 × 10 ³ ) = 9720 (cell time). Thus, a 14-bit counter is needed to monitor this traffic. This is because 2 ¹³ <9720 <2 ¹⁴ . On the other hand, the size of this cell monitoring counter is a value based on the lowest conceivable cell rate, and is actually smaller due to the type of traffic to be monitored and the negotiated data rate. For example, As can be seen as shown in 4 cases of the data cell rate is 6.48Mbps arrival interval between adjacent cells is set to T _icat 24 is sufficient as a 5-bit counter in order to monitor the traffic. Similarly, in the case of 12.96 Mbps, the arrival interval T _icat between neighboring cells is 12 by Equation 1 above, and is a 4-bit counter. In the case of 51.84 Mbps, the arrival interval T _icat between neighboring cells is It becomes 3 by 2 and becomes a 2-bit counter. In other words, as the traffic generation speed increases, the counter size for traffic monitoring can be made smaller. Due to the characteristics of the counter size as described above, in an environment such as a broadband network or a multimedia network, the amount of hardware installed to perform a Policing function in an ATM switch at this stage can be reduced.

On the other hand, since the cell monitoring mechanism according to the present invention is designed to monitor the data cell rate, it can be applied to rate-based ABR (Available Bit Rate) traffic control as it is. In the case of applying to credit-based ABR traffic control having excellent cell loss characteristics, the cell monitoring counter may be changed to count the number of data cells flowing into the switch node.

4. Receive function of cell control information

When one user data cell arrives, cell control information corresponding to the VPI / VCI value extracted from the 5-byte cell header is read from the look-up table 20. The initial counter control value Cc (counter control value) immediately after connection establishment is obtained by the following equation.

Cc = cell size ÷ (Rp × one_cell_time)

Here, Rp is the highest cell rate negotiated at connection establishment, and one_cell_time is 2.726 μsec from ATM UNI (User-Network Interface) speed.

When performing rate-based ABR traffic control, the control information Cc is used for cell rate control as it is, and credit-based ABR traffic control is used as control information for managing the occupancy of the buffer according to buffer management rules.

5. Cell Control Function

In order to add the accuracy of cell control, the present invention compares the cell monitoring information Cm and the cell control information Cc. If the cell monitoring information Cm is larger than the cell control information Cc, it means that the cell does not violate the current control parameter. If the cell monitoring information Cm is smaller than the cell control information Cc, the cell is assigned the current control parameter. It means a violation. FIG. 5 is an exemplary diagram for showing the use of cell monitoring information and cell control information. In the case where the control value for the current cell rate is 10 Mbps (equivalent to counter control value Cc equal to 16) An example of a cell Cm1 violating a traffic parameter and a cell Cm2 compliant are shown. Finally, the determination of whether the cell violates the parameter includes the allowable CDV for the cell delay variation from the traffic source to the monitoring function performing unit, in order to cope with the cell concentration effect due to statistical multiplexing. Meanwhile, the A_I bit, which is unique traffic control information, is used to determine whether the corresponding connection actually violates the negotiation parameter and to control access to an unused band.

6. Reporting function of cell monitoring information

By reporting the cell monitoring and control result information to the control plane, statistical data on incoming data cells is obtained, and management information of a specific connection is changed as necessary. Since the monitoring information Cm is larger than the control information Cc in most cases, the control information Cc is reset based on the monitoring information Cm. When the monitoring information Cm is smaller than the control information Cc, the monitoring information Cm is unconditionally reported and the cell control information Cc is immediately changed. Here, although the reported cell monitoring information is registered in the look-up table as the cell control information, the A_I bit must be set in addition to the direct use as the cell control information.

A preferred embodiment of the present invention will be described in detail with reference to FIGS. 1 to 5 and 7 described above.

6 is a flowchart of an algorithm for real-time cell monitoring and control according to an embodiment of the present invention.

In step 201, when the 53 bytes (BYTE) cell is received from the physical layer (P / L) of the ATM network, the HDPU 13 receives the VPI / VCI and CLP fields from the 5-byte header of the ATM cell shown in FIG. Extract and send to CADU 15. Then, in step 205, the CADU 15 determines the validity of the cell using the match flag value of the corresponding VPI / VCI in the look-up table 20 as shown in Table 1 below.

Example of look-up table VPI / VCI24 bits Match flag1 bit Cc14 bits CDV A_I1 bit CNS1 bit # 10 0 --- xx --- --- # 20 One xx xx 0 0 or 1 # 30 One xx xx One 0 or 1 # 40 0 or 1 xx xx 1 (o) 0 or 1 ··· ··· ··· ··· ··· ···

Where xx: counter value; Match flag, A_I, CNS: active high; (o): option.

In this case, the CADU 15 determines that the current cell is a valid cell generated from a connection that is legitimately connected if the corresponding flag of the VPI / VCI of the look-up table 20 corresponds to step 209. If the match flag ≠ 1 of the corresponding VPI / VCI in the look-up table 20 is determined to be invalid, the cell is discarded in step 207 and the next cell rate is monitored and controlled. In step 209, the CADU 15 receives Cm as monitoring information from the TMP 17 and reads Cc as control information from the look-up table 20. In step 211, the CADU 15 compares the monitoring information Cm with the control information Cc and checks whether the traffic parameter is violated. In this step, in order to cope with the concentration effect of the cell, the CDV value of the corresponding VPI / VCI of the LOOK-UP table 20, which is predetermined at the time of connection establishment, is used. ∥Cc-Cm∥ ＞ CDV If the value of Cc-Cm is less than or equal to the CDV value, the cell is allowed to be accepted by judging that it is legitimate, and the current cell control and monitoring is terminated. If the Cc-Cm value is greater than the CDV value, the process proceeds to step 212. If the Cm value is smaller than the Cc value, the process proceeds to step 213. Otherwise, the process proceeds to step 227. When the cell violation determination in steps 211 and 212 is summarized, it is determined that the Cm value is within the CDV value. In addition, when the Cm value does not fall within the CDV value, it is determined that the violation is Cc> Cm, and when Cc <Cm, it is determined to be legal. That is, it is determined that Cm2 and Cm3 in FIG. 7 are legal, Cm1 is in violation, and Cm4 is legal.

In order to check whether the negotiation parameter is violated in step 213, the CADU 15 reads the A_I bit value, which is traffic control information, from the look-up table 20 to determine whether the current user connection actually violates the negotiation parameter. For example, if the corresponding A_I bit value of the look-up table 20 is '1', it is determined to be a violation and proceeds to step 217. If the A_I bit value is '0', the step proceeds to step 215 and the cell is suppressed after step 229. Proceed to In step 217, the CLP bit value extracted from the cell header is searched, and if CLP = 1, the flow proceeds to step 219, and a control signal for discarding a cell, 'Discard Signal', is sent to the physical layer (P / L). If the CLP = 0, the CADU 15 sets the CLP bit value to '1' in step 221 and then sends a control signal and a 'TAG signal' to the physical layer (P / L) in step 223. Thereafter, in step 225, the PTI field value of the cell header for transmitting the ECN signal is changed to indicate the congestion of the cell.

On the other hand, after cell suppression in step 215, cell discard in step 219, and tag signal in step 223 are sent to the physical layer, the process proceeds to step 227, and CADU 15 reports the control result to MIRU 19. MIRU 19 reports the monitoring information Cm to the control panel. Thereafter, in step 229, the MDPP 30 updates the control information Cc in the look-up table 20 based on the monitoring information Cm. The reason for updating the control information Cc is that the next few nodes update for the traffic control of the cell when the previous control information Cc and the monitoring information Cm show a difference even though the currently received cell is valid. In this way, traffic can be controlled in real time.

When the monitoring and control of the traffic for the specific cell is completed as described above, the flow proceeds to step 231 to reset the timer (binary counter) and returns to step 201 to monitor and control the traffic of the next cell. Steps 201 to 231) are repeated in real time.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by the equivalents of the claims.

As described above, the present invention provides an algorithm that monitors and controls ATM traffic having various characteristics in real time, and accurately determines whether or not to comply with a negotiated traffic parameter when establishing a cell connection, and at the same time, statistical multiplexing of data cells. This has the effect of enabling efficient use of network resources.

In addition, by real-time management of ATM traffic, it can be effectively applied to ATM switches operating in the fixed bandwidth allocation method for CBR traffic in the future to efficiently handle various types of ATM services such as VBR, ABR, and UBR.

Claims (17)

In order to perform traffic monitoring and control, the AT cell control block which actually measures the time between two consecutive adjacent cells by the counter on the AT layer and reports it to the monitoring information processor, and controls according to the virtual path identifier / virtual channel identifier. A real-time traffic monitoring and control method in an asynchronous transmission mode switching node having a look-up table in which information, a valid value of a cell header, and a violation determination value are specified, Extracting a virtual path identifier / virtual channel identifier field and a cell loss priority field from the 5-byte cell header of the 53-byte AT cell; Determining whether a received cell is valid by examining a cell header valid value of the look-up table for the virtual path identifier / virtual channel identifier field extracted from the cell header; Checking whether the traffic parameter is violated by comparing the monitoring information and the control information when the valid cell is determined by the validity of the cell; Checking whether the current user connection violates the negotiation parameter by using the traffic control information value and the cell loss priority field value in the look-up table when it is determined that the violation is determined by the traffic parameter check; Suppressing, tagging, and discarding cells according to whether the negotiation parameter is violated; Sending a cell control result determined for the valid cell to a physical layer that actually performs cell processing; And reporting cell monitoring information to an upper control plate and resetting cell control information based on the cell monitoring information. The method of claim 1, The monitoring information is a real-time traffic monitoring and control method of the asynchronous transmission mode switching node, characterized in that the value measured by the binary counter on the HT layer actually between two consecutive adjacent cells. The method of claim 1, The control information is control information which is determined by the following equation immediately after the connection is established and assigned to the look-up table. Subsequent control information is newly updated in the look-up table based on the monitoring information when performing cell processing. Real-time traffic monitoring and control method in the asynchronous transmission mode switching node characterized in that the information. Cc = cell size ÷ (Rp × one_cell_time) Here, Cc is control information immediately after connection establishment, Rp is the highest cell rate negotiated at connection establishment, and one_cell_time is 2.726 μsec from ATM user network interface speed. The method of claim 1, The traffic parameter violation check using the monitoring information and the control information allows the cell if the monitoring information comes within an arbitrary cell delay variation allowance specified before and after the control information, and otherwise determines to violate the asynchronous transmission mode switching. Real time traffic monitoring and control method in node. The method of claim 4, wherein The random cell delay variation tolerance value is a value specified in a look-up table that is predetermined at the time of connection establishment, the real-time traffic monitoring and control method in an asynchronous transmission mode switching node. The method of claim 1, And if the cell is not valid according to the validity of the cell, discarding the cell and preparing for processing of the next received neighbor cell. The method of claim 1, If it is determined to be legitimate by the traffic parameter check, the method further comprises the step of allowing the cell, terminating the monitoring and control of the current cell, and preparing to process the next received neighbor cell. Real-time traffic monitoring and control in. The method of claim 2, The binary counter is a real-time traffic monitoring and control method of the asynchronous transmission mode switching node, characterized in that for determining the size of the minimum bit binary including the arrival interval between adjacent cells determined by the following equation. T _icat = line speed ÷ Rc Where line speed is the link speed of the traffic, Rc is the cell rate from the traffic source, and Ticat is the arrival interval between adjacent cells. In order to perform traffic monitoring and control, the AT cell control block which actually measures the time between two consecutive adjacent cells by the counter on the AT layer and reports it to the monitoring information processor, and controls according to the virtual path identifier / virtual channel identifier. It has a look-up table that specifies information, valid values of cell headers for determining validity of a cell, traffic control information values for criterion of violation of negotiation parameters, and allowable cell delay fluctuations predetermined at connection establishment. In the real-time traffic monitoring and control method in the asynchronous transmission mode switching node, Extracting a virtual path identifier / virtual channel identifier field and a cell loss priority field from a 5-byte cell header of a 53-byte AT cell received from the physical layer; Transmitting the virtual path identifier / virtual channel identifier field extracted from the cell header to the look-up table; Checking a cell header valid value of the look-up table for the virtual path identifier / virtual channel identifier field transmitted to the look-up table to determine whether the received cell is a valid cell originating from a legitimately established connection. Process, Reading the control information from the look-up table when it is determined to be a valid cell by the valid cell determination, and reading monitoring information, which is a value obtained by measuring a time between two consecutive adjacent cells, from a monitoring unit; If monitoring information comes within the allowable cell delay variation allowable range which is designated before and after the read control information, or if the monitoring information is larger than the control information, it is determined not to be violated, and within the cell delay variation allowance. A traffic parameter violation checking process determining that the monitoring information is less than the control information without monitoring information, Finally determining whether the current user connection actually violates the negotiation parameter through the traffic control information value in the look-up table when it is determined that the violation is determined by the traffic parameter violation check; If the cell is determined to be in violation according to whether the negotiation parameter is violated, discarding or tagging according to a cell loss priority field value; Sending a cell control result determined for the valid cell to the physical layer that actually performs cell processing; Reporting cell monitoring information to an upper control plate and resetting cell control information based on the cell monitoring information; When the monitoring and control of the received cell is completed, the counter is reset and the real time traffic in the asynchronous transmission mode switching node comprises the steps of sequentially performing the above steps in processing the next adjacent cell. Surveillance and Control Methods. The method of claim 9, Real time traffic monitoring and control method in an asynchronous transmission mode switching node, wherein the time measurement between two consecutive adjacent cells is performed by a binary counter on the AT layer. The method of claim 10, The binary counter is a real-time traffic monitoring and control method of the asynchronous transmission mode switching node, characterized in that for determining the size of the minimum bit binary including the arrival interval between adjacent cells determined by the following equation. T _icat = line speed ÷ Rc Where line speed is the link speed of the traffic, Rc is the cell rate from the traffic source, and Ticat is the arrival interval between adjacent cells. The method of claim 9, The control information is control information which is determined by the following equation immediately after the connection is established and assigned to the look-up table. Subsequent control information is newly updated in the look-up table based on the monitoring information when performing cell processing. Real-time traffic monitoring and control method in the asynchronous transmission mode switching node characterized in that the information. Cc = cell size ÷ (Rp × one_cell_time) Here, Cc is control information immediately after connection establishment, Rp is the highest cell rate negotiated at connection establishment, and one_cell_time is 2.726 μsec from ATM user network interface speed. The method of claim 9, And if the cell is not valid according to the validity of the cell, discarding the cell and preparing for processing of the next received neighbor cell. The method of claim 9, If it is determined that the traffic parameter is determined to be legitimate, the method further comprises the step of allowing the cell, terminating the monitoring and control of the current cell, and preparing to process the next neighbor cell. Real time traffic monitoring and control method in node. The method of claim 9, The traffic control information is a value for performing a determination on whether a corresponding connection actually violates a negotiation parameter and access control to an unused band. The method of claim 9, And changing the PTI field of the cell header for the tagsiCSI signal transmission to indicate congestion of the cell. The method of claim 9, And suppressing the cell if the corresponding cell is legal according to whether the negotiation parameter is violated.