KR100226997B1 - High rate call permit control method and apparatus based on the traffic monitoring - Google Patents

Abstract

The present invention relates to a traffic monitoring-based high speed call permission control apparatus. The present invention compares the size of the maximum cell rate in the corresponding class with the available available bandwidth when a call request having the maximum cell rate is made. At least one sub-call permission control means for determining and outputting a link capacity value; At least one buffer means for storing a link capacity value obtained from the sub-call permission control means of the corresponding class; Switching means for selecting a link capacitance value of said buffer means; Server means for obtaining a monitoring value for traffic corresponding to each class at a predetermined period from the selected link capacity value; And a capacity allocation control means for calculating a cell distribution function based on the obtained traffic monitoring value, calculating the available bandwidth based on the calculated bandwidth, and allocating the available bandwidth to the sub-call permission control means, based on the maximum cell rate and the probability distribution function of the traffic. It is possible to use an efficient link for any traffic source while controlling in real time using the call admission control scheme.

Description

Traffic monitoring based fast call permission control method and apparatus.

The present invention is based on the traffic monitoring using a parallel controller for the control of homogeneous traffic in the access control unit of an asynchronous transfer mode (ATM) exchange, the peak call rate (Peak Cell Rate) as a traffic parameter The present invention relates to a traffic monitoring-based fast call permission control method and apparatus for performing call permission control using only PCR) to achieve real-time increase of control and reduction of error through fast comparison operation.

In general, it is a traffic control technique when implementing an Asynchronous switching mode (ATM) switching method, which is a recommended method to provide an B-Integrated Service Digital Network (ISDN) service. It is equipped as an algorithm. In fact, these algorithms are commercialized in foreign countries and installed in their exchanges or only control algorithms are sold.

Typical call admission control (CAC) techniques currently used include call admission control based on equivalent bandwidth calculation and call admission control based on burst modeling.

In the call admission control scheme based on the former equivalent bandwidth calculation, this scheme approximates the bit rate occurring in the multiplexed connection to obtain the equivalent bandwidth, and then calls a new connection request when there is a connection request of a new call. It is a technique of determining whether to connect by determining whether the remaining bandwidth is exceeded.

The equivalent bandwidth means a bandwidth that satisfies the requirement for the quality of service of the call, has a value larger than the average cell rate and a value smaller than the peak cell rate.

There are various methods for calculating the equivalent bandwidth, and a representative method thereof is as follows.

This method calculates the equivalent bandwidth for each call regardless of the capacity of the entire physical link and then obtains the equivalent bandwidth for the entire traffic based on queuing analysis.

The equivalent bandwidth of each call whose cell loss rate requirement threshold is ε is calculated as

Where a = 1n ε, Rp is the maximum cell rate, ρ is the ratio of the average cell rate to the maximum cell rate, b is the average burst length, and X is the size of the buffer.

In this case, when n connections are multiplexed, the size C of the total bandwidth required is calculated as in Equation 2.

At this time, in order to consider the multiplexing effect, the size C of the total bandwidth is calculated as shown in Equation 3 by assuming Gaussian distribution for aggregated traffic.

는 분산을 나타낸다.Where m ₁ is the average bit rate,

Represents dispersion.

In addition, in the call admission control method based on the latter burst modeling, the technique uses a peak bit rate (PBR) regardless of the distribution of on / off intervals of a cell arrival processor. ) And average bit rate (ABR) to determine whether a call is connected.

The probability that the number of bursts (bursts) in the on state at any instant when multiple virtual channels with the maximum bit rate (PBR) = R and the average bit rate (ABR) = a is multiplexed becomes k Equation 4

Therefore, when k virtual channels are multiplexed in a link, the probability that the required bandwidth is kR is assumed to be P (n, k).

In this case, if the acceptance of the connection is determined as a probability that the utilization of the bandwidth used by the connected calls exceeds the threshold value, acceptance of the new call may be determined as shown in Equation 5 below.

This means that when the physical link bandwidth is C and the total number of connected calls including new calls is n, there is a probability that the amount of total bandwidth to be used by connected calls after the new call is connected will not exceed 90% of the physical link bandwidth. If it is less than the appropriate level, i.e. (1-ε), the connection is allowed, otherwise it is rejected.

However, in the call admission control scheme based on the equivalent bandwidth calculation used in the asynchronous transfer mode (ATM) switching scheme described above, it is difficult to calculate the exact equivalent bandwidth of the individual call layer in advance, and the link utilization efficiency when the number of traffic sources is small. Not only does it have a significant disadvantage, but it also poses a disadvantage in that it is difficult to control in real time due to problems in time and accuracy in calculating the total equivalent bandwidth.

In addition, in the call admission control method based on burst modeling, it is simpler than the call admission control method based on the equivalent bandwidth calculation. However, in heterogeneous traffic environments, the calculation is complicated and the relationship between burst traffic characteristics and quality of service is unclear. In addition to the disadvantages, the structure of the call permission control unit is complicated, which makes the implementation and real-time control difficult.

Accordingly, the present invention excludes a decrease in link utilization efficiency and computational complexity in a heterogeneous traffic environment in the conventional technique described above, and, in one aspect of the present invention, provides a maximum cell rate and a probability of traffic. It is an object of the present invention to provide a traffic monitoring-based fast call permit control method and apparatus for enabling efficient link use for arbitrary traffic sources while controlling in real time using a call permit control technique based on a distribution function.

Another aspect of the present invention is to increase the real-time control of the control based on traffic monitoring and using only the maximum cell rate as a parameter provided by the source.

In still another aspect of the present invention, an object of the present invention is to reduce the error of the controller and improve the utilization efficiency of the link, rather than the call admission control method based on the burst modeling.

Another aspect of the present invention is to prevent traffic over-entry in advance to prevent overload of the exchange.

Another aspect of the present invention is to improve the communication quality by reducing the control time required to enter a call.

1 is a block diagram showing an embodiment provided in the description of the traffic monitoring-based high speed call permit control apparatus of the present invention

2 is a block diagram showing in more detail the sub-call permission control unit of FIG.

3 is a signal flow diagram for calculating an equivalent bandwidth in an exchange using the asynchronous transmission scheme of FIG.

4 is a signal flow diagram for call admission control of FIG.

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

100: first sub-call permission control unit 101: second sub-call permission control unit

102: M sub-call permission control unit 103: first buffer unit

104: second buffer portion 105: M buffer portion

106: switching unit 107: server unit

In accordance with an aspect of the present invention, there is provided a traffic monitoring-based fast call permit control apparatus according to an aspect of the present invention, wherein the maximum cell rate in a corresponding class and the amount of available extra available bandwidth are available in a call request having a maximum cell rate. At least one or more sub-call permission control means for determining whether to accept a connection by comparing a value and outputting a link capacity value; At least one buffer means for storing a link capacity value obtained from the sub-call permission control means of the corresponding class; Switching means for selecting a link capacitance value obtained from said buffer means; Server means for obtaining a monitoring value for traffic corresponding to each class at a predetermined period from the link capacity value selected by the switching means; And a capacity allocation control means that obtains a cell distribution number based on the traffic monitoring value obtained by the server means, calculates the available bandwidth based on this, and allocates the available bandwidth to the sub-call permission control means.

In the traffic monitoring-based high speed call permission control apparatus according to the present invention, the one of the sub-call permission control means compares the input maximum cell rate with the size of the available bandwidth obtained by the capacity allocation control means. Way; And an available bandwidth calculating means for calculating a new available bandwidth with the available bandwidth and the maximum cell rate obtained by the comparing means.

In the traffic monitoring-based fast call permission control instrument according to the present invention, the capacity allocation control means includes: cell rate distribution determining means for obtaining a cell distribution function based on the traffic monitoring value obtained from the server means; And an effective usable bandwidth determining means for determining an available bandwidth based on the obtained cell distribution function and allocating the available bandwidth to one of the sub-call permission control means.

According to the present invention, the apparatus for monitoring high-speed call allowance according to the present invention determines the excess available bandwidth in the available bandwidth calculating means by subtracting the sum of the equivalent bandwidths of each class from the total link capacity.

According to another aspect of the present invention, there is provided a traffic monitoring-based fast call permission control method for achieving the above objects, comprising: receiving parameters required for calculating an equivalent bandwidth for traffic of an arbitrary class; Designating an upper limit and a lower limit of the equivalent bandwidth after inputting the parameter; Setting an intermediate value between an upper limit value and a lower limit value of the equivalent bandwidth; Calculating a cell loss rate for traffic of any second class in the corresponding update period of the equivalent bandwidth; Calculating whether the calculated cell loss rate is less than or equal to a cell loss rate requirement condition; Outputting the calculated equivalent bandwidth when the determination result is less than or equal to the cell loss rate requirement condition, and adding the next cell to the calculation when the cell loss rate requirement is greater than the limit value; Comparing the added cell loss rate with a cell loss rate requirement threshold and specifying a currently designated equivalent bandwidth as a lower limit if it is abnormal; Designating a currently designated equivalent bandwidth as an upper limit if the added cell loss rate is less than or equal to a cell loss rate requirement; And determining whether the number of counted cells is greater than a specified value after designating the lower limit value and the upper limit value, and repeating the steps after the upper limit value and the lower limit value specifying step and outputting an upper limit value of the currently designated equivalent bandwidth if the value is larger. It is done.

In the traffic monitoring-based fast call admission control method for achieving the objects of the present invention, the available bandwidth and the maximum cell rate of the new call available to the user in the network when there is a connection request of a new call of any second class Comparing; Rejecting a call connection if the available bandwidth is less than the maximum cell rate; And if the available bandwidth is greater than the maximum cell rate, permitting the connection of the call and updating the available bandwidth.

Hereinafter, with reference to the accompanying drawings it will be described in detail a preferred embodiment of a traffic monitoring-based fast call permit control apparatus according to the present invention.

First, prior to the description of the present invention, the call permission controller should be capable of real-time control while enabling efficient link usage for any traffic source.

In order to satisfy both of these conditions, the present invention proposes a controller having a parallel structure and a call admission control scheme based on the peak cell rate (PCR) and the probability distribution function of traffic.

The proposed parallel controller has M first to M sub-call permission control units 100 to 102.

Calls requesting connection are determined by the controller of the corresponding class among the M control units, and whether the call is accepted by the controller of the class, and the cells generated in the corresponding class are output terminals of the first to the Mth sub-call permission control units 100 to 102. It is stored in the first to the M-th buffer unit 103 to 105 connected to.

The proposed method uses only the maximum cell rate as a traffic parameter provided by the user.

The reason is that the average cell rate is not suitable as a traffic parameter for call admission control because it may be impossible for traffic sources to accurately estimate the average cell rate in the case of specific traffic.

In contrast, the maximum cell rate can be estimated relatively accurately.

However, when the call admission control is performed only by the maximum cell rate except the average cell rate, the information on the traffic is insufficient. Therefore, the probability distribution function for the number of cells arriving during a certain measurement period is obtained through the actual measurement of the traffic.

From the probability distribution function, we estimate the equivalent bandwidth used by the current traffic.

The proposed technique accepts a connection if the maximum cell rate of the call is less than the available extra bandwidth when a new call has made a connection request, and otherwise rejects the connection.

The extra bandwidth is determined by subtracting the sum of the equivalent bandwidths of each class from the total link capacity.

According to the present invention, since the call admission control is performed using only the maximum cell rate as a parameter provided by the traffic source, the structure of the controller is simpler than the call admission control method based on the equivalent bandwidth calculation, and the real-time Increases.

In addition, the efficiency of the link can be improved by reducing the error of the controller compared to the call admission control method based on the burst modeling.

In addition, congestion in a computer communication network is caused when a larger amount of traffic flows than a traffic capacity that can be handled in a network, and may be caused by unpredictable fluctuations in traffic flow or failure in the network.

Among them, cell loss due to buffer overflow is the biggest source of error in the high-speed communication network environment where the error rate is very low such as asynchronous transmission mode (ATM) network.

Congestion in ATM networks can greatly degrade the quality of service, and a series of actions taken to minimize the effects of congestion is called congestion control.

Congestion control schemes that can be used in ATM networks are divided into two types: preventive congestion control scheme and reactive congestion control scheme.

The preventive congestion control technique is a technique for performing appropriate control before traffic congestion occurs by predicting traffic conditions of a communication network.

In high-speed transmission protocols such as ATM, the performance of the preventive congestion control technique is reported to be superior to the adaptive congestion control technique.

One of the preventive congestion control techniques is the call admission control technique.

Call admission control is defined as a series of operations performed by a communication network to control a virtual channel connection (VCC) or a virtual path connection (VPC) during a call connection process.

The purpose of call admission control is to determine whether to connect a new call when there is a connection request, so as not to deteriorate the traffic occurring in the new call and the quality of service of the existing connected call.

The network user waits for the decision of call connection after presenting the parameters of the user traffic and the quality of service information to the access controller of the access node.

At this time, call admission control should be able to control in real time and should be designed to have high link efficiency within the range that can guarantee the service quality of user traffic.

Therefore, the call admission control method in the present invention proposes a controller that has a parallel structure and a call admission control scheme based on the maximum cell rate (PCR) and the probability distribution function of traffic.

The proposed parallel controller has M first to M sub-call permission control units 100 to 102.

Calls requesting connection are determined by the controller of the corresponding class among the M controllers, and whether or not the call is accepted in the corresponding class, and the cells generated in the corresponding class are output terminals of the first to the Mth sub-call permission controllers 100 to 102 respectively. It is stored in the first to M-th buffer unit 103 to 105 connected to.

For call control for uniform traffic, we propose a control method that can provide efficient link usage for any traffic source with high real-time controllability.

The proposed method uses only the maximum cell rate as a traffic parameter provided by the user.

The reason is that the average cell rate is not suitable as a traffic parameter for call admission control because it is sometimes impossible for traffic sources to accurately estimate the average cell rate in the case of specific traffic, but the maximum cell rate can be estimated relatively accurately. to be.

However, when call admission control is performed based only on the maximum cell rate excluding the average cell rate, the information on the traffic is insufficient. Therefore, the probability distribution function for the number of cells arriving during a certain measurement period is obtained through the actual measurement of the traffic.

From the probability distribution function obtained above, the equivalent bandwidth used by the corresponding traffic in each class is estimated.

Thus, the proposed scheme accepts the connection if the maximum cell rate of the call is less than the extra bandwidth available when a new call has made a connection request, and otherwise refuses the connection.

The extra bandwidth is determined by subtracting the sum of the equivalent bandwidths of each class from the total link capacity.

This will be described in detail with reference to FIG. 1.

1 is a block diagram showing an embodiment provided in the description of the traffic monitoring-based high speed call permission control apparatus of the present invention.

According to the present embodiment, when there is a call request having the maximum cell rate from the first to Mth input terminals 108 to 110, the size of the maximum cell rate in the corresponding class and the available spare bandwidth are compared. A first to Mth sub-call permission control unit (100 to 102) for determining whether to accept the connection and outputting a link capacity value, the first to Mth buffer units (103 to 105) of the corresponding class, and the first to The switching unit 105 which selects the capacitance value input from the M-th buffer units 103 to 105 and the monitoring value for the traffic corresponding to each class at a predetermined period from the link capacitance value selected by the switching unit 106. Obtain a cell distribution number by the server unit 107 outputting through the output terminal 111 and the traffic monitoring value input from the server unit 197, and calculates the available bandwidth based on the first to M Consists of a capacity allocation controller (112) that assigns the call to allow the control probe (100 to 102).

Also. The first sub call permission control unit 100 may include a comparison unit 100a and a comparison unit 100a that compare the maximum cell rate to be input with the available bandwidth input by the capacity allocation control unit 112. It consists of an available bandwidth calculation unit 100b for calculating a new available bandwidth with the available available bandwidth and the maximum cell rate.

In addition, the capacity allocation control unit 112 is a cell rate distribution determining unit 112a for obtaining a cell distribution function based on the traffic monitoring value input from the server unit 197, and available based on the obtained cell distribution function. It is configured to the effective available bandwidth determination unit 112b for determining the bandwidth and assigning it to the first to the M-th sub-call permission control unit (100 to 102).

As such, the configured traffic monitoring-based fast call permission control device first allocates bandwidth allocation to the parallel controller when there are M classes of traffic sources flowing from the first to Mth input terminals 108 to 110 for call permission control. There is a capacity allocation control unit 112 and the first to M-th buffer unit (193 to 105) for each.

When there is a connection acceptance request of the calls entering the access node, the first to the M-th sub-call permission control units 100 to 102 of the class determine whether to accept the connection.

The asynchronous transmission mode cells entering from the connected call are stored in the first to Mth buffer units 193 to 105 connected to the first to Mth sub-call permission control units 100 to 102 to wait for a service.

Every time traffic for each class is monitored and the equivalent bandwidth is updated.

In the first to Mth sub-call permission control units 100 to 102, if the call of the corresponding class provides the maximum cell rate R _p as a traffic parameter, the comparison unit 100a compares the available bandwidth with the available bandwidth to determine whether to accept the connection. Will be determined.

At this time, if the call is connected, the available bandwidth calculating unit 100b of the sub-call permission control unit 100 to 102 subtracts the maximum cell rate R _p from the calculated available bandwidth to recalculate a new available bandwidth to generate the first to second. It inputs to the M buffer parts 103-105.

As a result of the comparison by the comparing unit 100a, if the available bandwidth is greater than the maximum cell rate of the call, the connection is allowed. If the available bandwidth is less than the maximum cell rate of the call, the connection is rejected.

The size of the available bandwidth is determined by subtracting the sum of the equivalent bandwidths of each class from the total link capacity.

The first to Mth buffer units 103 to 105 store the output values of the first to Mth sub-call permission control units 100 to 102 and provide them to the server unit 107 through the switching unit 106. Done.

The server unit 107 obtains a monitoring value for traffic corresponding to each class at a predetermined period from the first to Mth buffer units 103 to 105 and outputs it through the output terminal 111. In addition, it is provided to the cell rate distribution determining unit 112a of the capacity allocation control unit 112.

The cell rate distribution determining unit 112a obtains three distribution functions based on the traffic monitoring value input from the server unit 107 and provides them to the effective available bandwidth determining unit 112b.

The effective available bandwidth determination unit 112b calculates an available bandwidth based on the cell distribution function obtained by the cell rate distribution determination unit 112a and allocates the available bandwidth to the first to Mth sub-call permission control units 100 to 102. Done.

That is, the capacity allocation control unit 112 determines the service capacity for each class.

The equivalent bandwidth of each traffic class to the sum of the bandwidths of all the traffic classes is defined as class capacity.

The server unit 197 scheduled by the class capacity transfers the cells stored in the buffer of each class to the physical channel by round robin.

The traffic measurement above is an important measurement parameter in the case of actually measuring the traffic multiplexed on the link.

a) Renewal period: N

One update period consists of N measurement periods.

In other words, update after N measurements.

In the case of a long update period, the dynamic adaptability to the change of traffic is reduced, but the effect of time delay for calculating the bandwidth used is reduced.

On the other hand, if the update period is shorter, the adaptation is quicker due to the change in traffic, but the number of samples is reduced, which reduces the accuracy of probability distribution.

b) Measurement Reflectiom Ration: a

This value is a weight that determines how much the value obtained through the actual measurement is reflected in the existing probability distribution function.

In the probability distribution function estimation, the probability that the number of K cells arrived during the measurement period S in the nth update period is called P ^{(i) n} n (k ⁽ⁱ⁾ ; n).

It is best to know this probability distribution function, but it is difficult to define it correctly. Therefore, we estimate this probability distribution function as P ⁽ⁱ⁾ n (k ⁽ⁱ⁾ ; n).

P ⁽ⁱ⁾ n (k ⁽ⁱ⁾ ; n + 1) = aq ⁽ⁱ⁾ (k ⁽ⁱ⁾ ; n) + (1-a) p ⁽ⁱ⁾ (k ⁽ⁱ⁾ ; n)

R in Equation 7 denotes the maximum number of cells that can arrive during the measurement period and estimates the probability distribution function when the call with the maximum cell rate R _p is accepted as in Equation 8.

R = sR _P ⁽ⁱ⁾

R

R

0 k ⁽ⁱ⁾ <R

If the existing call multiplexed on the link is released, no action is taken to simplify control.

This wastes bandwidth for a while, but is actually calculated by the actual bandwidth.

Given the probability distribution function for the number of cells arriving during the measurement period s, the cell loss rate in the nth update period is given by Equation (9).

Using Equation 9, a bandwidth satisfying a limited cell loss rate may be obtained.

⁽ⁱ⁾으로 정의한다.And, the equivalent bandwidth calculation, the service requirements for the cell loss rate of the user for any first class of traffic

^It is defined as ⁽ⁱ⁾ .

Given the estimated value of the probability distribution function p ⁽ⁱ⁾ (k ⁽ⁱ⁾ ; n + 1) of the number of cells to be transmitted during the measurement period s by the traffic of class i in the (n + 1) th update period, it is i-th from this The equivalent bandwidth C ⁽ⁱ⁾ used by the traffic of the class can be calculated.

The calculation algorithm of the proposed equivalent bandwidth for any i th class is shown in FIG.

The calculation of the equivalent bandwidth in detail with reference to FIG. 3 is as follows.

First, parameters necessary for calculating the equivalent bandwidth are received (step ST100).

Here, the parameter P ⁽ⁱ⁾ means the maximum value (Peak) for the traffic of the i-th class and A ⁽ⁱ⁾ means the average value for the traffic of the i-th class.

In the case of Variable Bit Rate (VBR) service, the equivalent bandwidth is determined between the average cell rate and the maximum cell rate.In this case, the initial value is P ⁽ⁱ⁾ with the upper limit b ⁽ⁱ⁾ and A ⁽ⁱ⁾ with the lower limit a ^(i). (Step ST101).

Then, an intermediate value between the lower limit a ⁽ⁱ⁾ and the upper limit b ⁽ⁱ⁾ is set to the equivalent bandwidth (step ST102).

Then, the cell loss rate P ⁽ⁱ⁾ loss (n) for the i-th class traffic in the update period is calculated (step ST103).

⁽ⁱ⁾이면 단계(ST105)로 진행하고 셀손실율이

⁽ⁱ⁾가 아니면 단계(ST106)로 진행한다.The calculated cell loss rate

⁽ⁱ⁾ proceed to step ST105 and the cell loss rate is

^{If not (i)} , the flow advances to step ST106.

⁽ⁱ⁾이면 이때 계산된 등가대역폭이 크리티컬한 값이므로

⁽ⁱ⁾를 출력하고 종료한다.In step ST105, the cell loss rate is

⁽ⁱ⁾ then since the equivalent bandwidth calculated here is a critical value,

Print ⁽ⁱ⁾ and exit.

⁽ⁱ⁾가 아니면 다음 셀을 계산에 추가한다.In step ST106, the cell loss rate is

^{If not (i)} , add the next cell to the calculation.

⁽ⁱ⁾보다 크면 단계(ST108)로 진행한다.Then, in step ST107, the cell loss rate is

^If greater than ⁽ⁱ⁾ , the flow advances to step ST108.

⁽ⁱ⁾ In step ST108, the cell loss rate is

⁽ⁱ⁾

⁽ⁱ⁾보다 작으면 현재 지정된 등가대역폭이 실제트래픽에 비해 over estimate된 상태이므로 상한치로 현재의 등가대역폭을 지정한 후 단계(ST110)로 진행한다.In step ST109, the cell loss rate is

If it is smaller than ⁽ⁱ⁾ , since the currently designated equivalent bandwidth is over estimated compared to the actual traffic, the current equivalent bandwidth is designated as the upper limit and the process proceeds to step ST110.

In step ST110, if the number of cells counted so far is smaller than the specified value N, the process after step ST101 is repeated. If the number of cells counted so far is greater than the specified value N, one update period ends. The process is regarded as having been completed and the process proceeds to step ST111.

In the above step ST111, since the currently designated upper limit value b ⁽ⁱ⁾ becomes the equivalent bandwidth in the state where one update period is completed ^{, the} value b ⁽ⁱ⁾ is output and ends.

In addition, in the connection acceptance control scheme, it is considered that one update period is performed in a short manner.

This gives the probability distribution function for the bandwidth used by the currently connected traffic, the bandwidth available to the user, and the number of cells at the start of the nth update period.

If a connection request is received for a new call of class i, the network compares the maximum cell rate of the new call with the available bandwidth available to the user.

If the available bandwidth is greater than the call's maximum cell rate, the call is allowed to connect. If the available bandwidth is less than the call's maximum cell rate, the call is rejected.

This will be described in detail with reference to FIG. 4 as follows.

That is, when a connection request of a new call corresponding to the i th class is received, the communication network compares the available bandwidth C _BW available to the user with the new cell rate R _P ⁽ⁱ⁾ (step ST112).

If the available bandwidth is greater than the maximum cell rate as a result of the comparison in step ST112, the process proceeds to step ST114.

If the available bandwidth is smaller than the maximum cell rate, the process proceeds to step ST113.

In step ST114, if the available bandwidth is greater than the maximum cell rate of the call, the connection of the call is allowed.

In step ST113, if the available bandwidth is less than the maximum cell rate of the call, the connection is rejected and terminated.

Then, when the connection of the new call is allowed, the available bandwidth C _BW is updated (step ST115).

As described above, in the present embodiment, an effective link can be used for any traffic source while performing real-time control using a call permission control method based on the maximum cell rate and the probability distribution function of the traffic.

In addition, while specific embodiments of the present invention have been described and illustrated above, it is obvious that the present invention may be variously modified and implemented by those skilled in the art.

Such modified embodiments should not be individually understood from the technical spirit or the prospect of the present invention, and such modified embodiments should fall within the appended claims of the present invention.

It is clear from the above description that a relatively simple hardware enables efficient link use for arbitrary traffic sources while real-time control using a call admission control technique based on the maximum cell rate and the probability distribution function of the traffic. It is possible to prevent the overload of the exchange by preventing the entry in advance.

In addition, it is possible to improve communication quality by reducing the control time required for entering a call through a simple comparison operation.

Claims (6)

At least one sub-call permission control means for determining whether to accept a connection and outputting a link capacity value by comparing the magnitude of the maximum cell rate in the corresponding class with the available extra available bandwidth in a call request having a maximum cell rate; At least one buffer means for storing a link capacity value obtained from the sub-call permission control means of the corresponding class; Switching means for selecting a link capacitance value obtained from said buffer means; Server means for obtaining a monitoring value for traffic corresponding to each class at a predetermined period from a link capacity value selected by the switching means; A traffic monitoring-based fast call permit, comprising: a capacity allocation control means for obtaining a cell distribution number based on the traffic monitoring value obtained from the server means, calculating the available bandwidth based on the calculated bandwidth, and assigning the available bandwidth to the sub-call permission control means; controller. 2. The apparatus of claim 1, wherein the sub-call permission control means comprises: comparison means for comparing the input maximum cell rate with the size of the available bandwidth obtained by the capacity allocation control means; And an available bandwidth calculating means for calculating a new available bandwidth with the available bandwidth and the maximum cell rate obtained by the comparing means. 3. The apparatus of claim 2, wherein the available bandwidth in the available bandwidth calculating means is determined by subtracting the sum of equivalent bandwidths of each class from the total link capacity. 2. The apparatus of claim 1, wherein the capacity allocation control means comprises: cell rate distribution determining means for obtaining a cell distribution function based on a traffic monitoring value obtained from the server means; And an available available bandwidth determining means for determining an available bandwidth based on the obtained cell distribution function and allocating the available bandwidth to one of the sub-call permission controlling means. Receiving parameters necessary for calculating an equivalent bandwidth for traffic of any second class; Designating an upper limit and a lower limit of the equivalent bandwidth after inputting the parameter; Setting an intermediate value between an upper limit value and a lower limit value of the equivalent bandwidth; Calculating a cell loss rate for traffic of any second class in the corresponding update period of the equivalent bandwidth; Determining whether the calculated cell loss rate is less than or equal to a cell loss rate requirement condition; Outputting the calculated equivalent bandwidth when the determination result is less than or equal to the cell loss rate requirement condition; and adding the next cell to the calculation when the cell loss rate requirement is less than the limit value; Comparing the added cell loss rate with a cell loss rate requirement threshold and specifying a currently designated equivalent bandwidth as a lower limit if it is abnormal; Designating a currently designated equivalent bandwidth as an upper limit if the added cell loss rate is less than or equal to a cell loss rate requirement; Determining whether the number of counted cells is greater than a specified value after specifying the lower limit value and the upper limit value, and repeating the steps after the upper limit value and lower limit value specifying step and outputting an upper limit value of the currently designated equivalent bandwidth if the value is larger. A traffic monitoring based fast call admission control method 6. The method of claim 5, further comprising: comparing a maximum cell rate of a new call with an available bandwidth available to a user in a network when there is a connection request of a new call of any second class; Rejecting a call connection if the available bandwidth is less than the maximum cell rate; And comparing the available bandwidth with the available bandwidth if the available bandwidth is greater than the maximum cell rate, and updating the available bandwidth.

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