JPH09181748A - Packet communication system - Google Patents

Abstract

(57) Abstract: To provide a more stable and highly efficient packet communication system according to packet traffic. A packet communication system of the present invention monitors traffic of a packet input from an input path, compares the traffic with a predetermined threshold value, and when the threshold value is exceeded, Monitor device (1
8), and when receiving the excess notification issued by the monitor device, a packet control device (17) for controlling the packet input within a predetermined control period, and the packet control device among the input packets. A connection device (19) for connecting an uncontrolled packet to an output path to be output.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to traffic control in a packet switching system, and more particularly to ATM (asyn
chronous transfer modes) The present invention relates to a packet communication system capable of providing a more stable communication service by introducing traffic control suitable for regulation of reception cell monitoring / discarding and marking during exchange.

[0002]

2. Description of the Related Art In an ATM exchange, a subscriber terminal declares parameters of a traffic called a cell transmitted during a call setup to a network (exchange) at the time of a call when the call is originated. It has been proposed to perform bandwidth allocation based on this. Conventionally, a method of monitoring traffic in a packet communication system is to assign a weighted value to the passage of a packet in a past sampling period that is retroactive from the measurement time, hold a sum of the values in a counter, and store the sum in a counter. When the counter exceeds a certain value while updating the counter along with the transition of, the packet passing frequency is determined to be excessive, and the single leaky bucket method can be considered as one of them.

[0003] Further, if a packet is transmitted in excess of the traffic declared by the terminal, congestion occurs, causing problems such as an increase in delay / loss of a packet transmitted from another terminal. It is necessary to monitor the traffic and take measures such as discarding if the traffic is exceeded.

[0004]

In the packet communication system, if the amount of incoming packets exceeds the processing capacity, the packets cannot be normally connected.
In order to provide more stable communication, it is necessary to constantly monitor packet traffic.

Here, in traffic monitoring in a packet communication system, there are cases where it is monitored whether or not each packet passes together in a short time. For example, in the monitoring of the cell arrival frequency in an ATM switch that handles packets called cells, the cell overflow rate in the switch depends on whether or not the traffic is such that concentrated arrivals are repeated in a short time. This type of monitoring is important because it will be greatly affected. A group of cells that arrive intensively in a short time is called a burst. That is, ATM
In the exchange, it is necessary to monitor whether or not a cell has arrived as a burst, and if the cell has arrived as a burst, the size of the burst is within an allowable range. When the prior art of the preceding paragraph is applied to the monitoring of the burst property, even cells arriving as bursts during the sampling period are weighted in the same manner as cells arriving randomly, so that they may arrive at the counter as bursts. There is the first problem that it is not reflected and it is difficult to monitor burst arrival accurately.

An object of the present invention is to solve the above problems and to provide a more stable packet communication system by providing a monitoring device capable of detecting that packet passages occur collectively in a short time. is there.

Further, in the above-mentioned conventional technique, the regulation of discarding or delay is applied to a cell when the monitoring mechanism determines that the received traffic exceeds the declared traffic due to the arrival of the cell. . Therefore, the ratio of cells to be regulated is determined by the frequency of detecting the traffic excess detection frequency peculiar to the monitor mechanism. However, in general, the frequency of detection of excess traffic does not match the ratio of cells to be regulated (frequency of occurrence of cells to be regulated). Therefore, in the above-mentioned conventional technique, unless the traffic excess detection frequency of the monitor mechanism is adjusted so that the traffic excess detection frequency and the ratio of the regulated cells match, the amount of cells subject to the regulation becomes excessive. There was a problem that it would run short. Further, in the above-mentioned conventional technique, the regulation of the cell is not reflected in the monitor mechanism. In other words, as a result of monitoring traffic including restricted cells, the monitoring mechanism continues to detect excess traffic volume regardless of whether the traffic of unpassed cells is larger or smaller than the declared traffic. There was a second problem in that the amount of target cells becomes excessive or insufficient.

The present invention solves such a problem and provides a packet communication system having a higher execution rate, which is provided with a monitor device or the like in which the ratio of regulated cells does not become excessive or insufficient. is there.

[0009]

In order to achieve the above object, the present invention monitors the traffic of packets input from the input path, compares the traffic with a predetermined threshold value, and A monitor device that issues an excess notification when the threshold is exceeded, and a packet control device that controls a packet input within a predetermined control period when the excess notification issued by the monitor device is received, and the input device. And a connection device for connecting a packet not controlled by the packet control device to the output path to be output.

In order to achieve the above object, according to the present invention, the packet control device is arranged in front of the monitor device for packet input, and packets controlled by the packet control device are monitored by the monitor device. It has a configuration to be excluded.

In order to achieve the above object, the present invention sets the control period of the packet control device to be long for a monitor device which frequently detects excessive traffic, and to set a monitor device which rarely detects excessive traffic. Has a configuration to be set short.

In order to achieve the above-mentioned object, the present invention controls the traffic of an input means for inputting a packet from the outside and the packet connected to the input means according to a certain condition and outputs the packet. Traffic control means, connection means for connecting a packet output from the traffic control means to a route different from the input route, first monitoring means for monitoring the maximum bandwidth of the traffic, and an average of the traffic Second monitoring means for monitoring the bandwidth, wherein the traffic control means is the first
It has a configuration for controlling the traffic based on the monitoring result of either the monitoring means or the second monitoring means.

In order to achieve the above object, the present invention comprises a plurality of monitoring means for monitoring packet traffic within different monitoring times, and the traffic control means has a monitoring result of any one of the plurality of monitoring means. And a structure for controlling the traffic based on

In order to achieve the above object, the present invention provides a first monitoring means for monitoring packet traffic within a first monitoring time at a monitoring point in a packet communication system, and the first monitoring time. Second monitoring means for monitoring packet traffic within different second monitoring times.

In order to achieve the above object, the present invention provides a first leaky bucket for monitoring the maximum bandwidth of the traffic, a burst length monitoring device for monitoring the burst state of the traffic, and an average bandwidth of the traffic. A second leaky bucket for monitoring, and the traffic control device has a configuration for controlling the traffic based on a monitoring result of any one of the first leaky bucket, the burst length monitoring device, and the second leaky bucket. .

In order to achieve the above-mentioned object, the present invention comprises a computing unit comprising a plurality of computing units connected in series to perform a computation based on a packet input to the packet communication system and output a computation result. A burst traffic monitoring device that monitors burst traffic based on a calculation result of the calculation unit, and a packet that is input to the input path based on a monitoring result of the burst traffic monitoring device is switched and connected to an appropriate output path. In the arithmetic unit, the number of packets input from the input path is input to the first arithmetic unit of the arithmetic units arranged in series in the arithmetic unit, and the arithmetic unit of the second or subsequent stage from the first is input. Has a configuration in which the arithmetic result of the immediately preceding arithmetic means is input and the output of the arithmetic means at the last stage is output as the arithmetic result of the arithmetic unit.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a diagram showing the structure of an ATM exchange to which the present invention is applied. In Figure 1, the trunk line of the exchange, etc.
Parts unnecessary for the description of the present invention are omitted.

The ATM exchange 12 shown in FIG. 1 has an exchange controller 13, a subscriber circuit 14, and a switch 19 as main parts. The three parties operate as follows when the terminal 11 communicates. That is, first, the terminal 11 divides a call setting signal into a packet called a cell through the subscriber line link 111 to the ATM exchange 12 and transmits the packet, and receives the signal by the exchange control unit 13 in the ATM exchange 12. The switching control unit 13 sets the subscriber circuit 14 and the switch 19 to a state in which the terminal can perform communication based on the parameters of the call setting signal. During communication, the terminal 11 breaks down the information data into cells and transmits them to the exchange 12 through the subscriber line information link 112. The information cells are input to the switch 19 via the subscriber circuit 14, and are transmitted to the switch 19 to the destination. Is performed.

This is performed by the exchange control unit 13 in FIG.
4 shows a flow of a setting process for the subscriber circuit 14 when a call setting signal is received. Hereinafter, in FIG. 10, the frequency of detection of the excess of the declared traffic in the block 1002 and the blocks 1003 to 1003-
The addition values 1, 2, 3, 4 and the subtraction values 1, 2,
The method for determining the parameters 3, 4 and the threshold values 1, 2, 3, 4 will be described in detail.

Among the above parameters, additional values 1, 2,
3,4, subtraction rate 1,2,3,4, threshold value 1,2,3
4 is a parameter of the leaky bucket. 2 to 6, the above A using a leaky bucket mechanism is used.
The traffic monitoring in the TM switch will be summarized, and after that, the leaky bucket front stage 18 in the average burst length monitoring unit 183 according to the present invention will be described with reference to FIGS. 7 to 9.
4, and parameters of the leaky bucket second stage 185,
A method of determining the addition values 3 and 4, the subtraction rates 3 and 4, and the threshold values 3 and 4 will be described.

FIG. 2 shows an example of changes in the counter of the leaky bucket mechanism. In FIG. 2, a ratio between the subtraction value and a fixed period for performing the subtraction is defined as a subtraction rate (Rsub).

FIG. 3 shows the interpretation of the parameters in FIG. 2 when the leaky bucket mechanism is viewed as a kind of queuing system. In FIG. 3, reference numeral 32 denotes a queue model of the leaky bucket mechanism, in which there are 31 monitoring events as an input, and there is a queue length overflow as an output, which means that 33 monitoring events are excessively generated. In FIG.
The addition value Nadd and the subtraction rate Rsu which are the parameters in FIG.
b, the threshold value Nmax determines the parameter holding time h of the queue system 32 and the number m of waiting rooms. The holding time h and the number of waiting rooms m determine the nature of the leaky bucket, as shown at 34. That is, the addition value Nadd, the subtraction value Rsub, and the threshold value Nmax are not independent of each other,
If the holding time h and the number of waiting rooms m are determined, one of the three may be fixed and the other two may be determined.

In FIG. 4, the traffic types to be monitored, their distribution, and the monitoring parameters show the allocated bandwidth.
The monitoring parameters in FIG. 4 are the maximum bandwidth monitoring leaky bucket 181 in FIG. 1, the maximum bandwidth is the average bandwidth monitoring leaky bucket 182 in FIG. 1, and the average burst length is the average burst length monitoring in FIG. In part 183,
Be monitored. Hereinafter, regarding the traffic shown in FIG.
When an overflow occurs in the leaky bucket mechanism, it is determined that the traffic report value is violated, and a method of determining the parameters h (reservation time) and m (the number of waiting rooms) is qualitatively described.

First, a method of determining h (holding time) will be described.
The maximum bandwidth, the average bandwidth, and the burst length of the traffic monitoring parameters shown in FIG. 4 differ in the time scale for observing the frequency of cell arrival. This corresponds to the time scale of seeing <1> input changes in the nature of the leaky bucket mechanism described in FIG.

FIG. 5 shows the correspondence between the monitoring parameters and the nature of the leaky bucket of <1> in FIG. 334. h
The determination scale of (reservation time) is shown. The figure shows that, for example, when it is desired to monitor the average band, the value of h (reservation time) should be increased, and therefore the ratio between Nadd and Rsub should be increased.

Next, a method of determining m (the number of waiting rooms) will be described. In order to effectively discriminate between traffic that does not violate the declared value and traffic that violated, increase the difference between the overflow probabilities of the two and make the absolute value of the overflow probability occur within a significant monitoring time, m and h must be determined. The properties of and are in a trade-off relationship, and correspond to the property of <2> in FIG. Since h has restrictions in the selection of monitoring parameters, m is used to determine the optimal trade-off relationship with h.

FIG. 6 shows the violation detection accuracy and the violation detection time.
A determination scale for m (the number of waiting rooms) in accordance with the property of the leaky bucket mechanism of <2> in FIG. 334 is shown.

As described above, with reference to FIG. 2 to FIG.
The traffic monitoring in the ATM switch using the bucket mechanism was organized. With this arrangement, it is possible to determine each parameter of the addition value 1, the subtraction rate 1, the threshold value 1, and the addition value 2, the subtraction rate 2, and the threshold value 2, and the traffic excess detection frequency. That is, the addition value 1, the subtraction rate 1,
For a threshold value of 1, a leaky
Because of the bucket parameters, h
(Holding time) is determined, and m (the number of waiting rooms) is determined using FIG. 6 from the viewpoint of the accuracy of traffic excess detection. By determining m (the number of waiting rooms), the traffic excess detection frequency is determined, and if one of the three parameters of addition value 1, subtraction rate 1, and threshold value 1 is fixed, two parameters of the value are determined. . The addition value 2, the subtraction rate 2, and the threshold value 2 can also be determined in the same way by being parameters of the leaky bucket for monitoring the average band.

Next, the operation of the average burst length monitoring unit 183 in FIG. 1 having the leaky bucket mechanism of the multi-stage structure will be described with reference to FIGS. 7 to 9, and the addition value 3, the subtraction rate 3, and the skew value will be described. 3 and a method of determining each parameter of the addition value 4, the subtraction rate 4, and the darkness value 4 will be described.

FIG. 7 shows the average burst length monitoring unit 1 in FIG.
It is a figure showing the internal configuration of 83. 7, the average burst length monitor 183 has two leaky bucket mechanisms 184 and 185. At the time of call setting, in the leaky bucket former stage 184, the registers 1841 to 184 are passed through the parameter setting unit 713 determined by the exchange control unit 13 based on the traffic report parameter indicated in the call setting signal.
3 is stored. At the same time, the counter register 3 (C
1,715) is cleared to zero. After the communication is started, the arithmetic unit 711 causes the registers 1841 to 184
An operation is performed on 3,715. That is, the regulation unit 1
When a cell is input from the switch 7 to the switch 19, the operation unit 71
1 is to counter register 3 (C1, 715)
The value of the addition value register 3 (Nadd3, 1841) is added. When the timer 712 is activated at regular intervals, the arithmetic unit 711 causes the counter register 3 (C1,
715) is subtracted by the value of the product of the subtraction rate register 3 (Rsub1, 1842) and a fixed period so that the result does not become negative. Also, the overflow detection unit 714
Indicates that the cell is input from the regulating unit 17 to the switch 19, and the calculation unit 711 causes the counter register 3 (C1, 715)
Is added, the counter register 3 (C1,
715) and threshold register 3 (Nmax1, 184)
3) and compare with counter register 3 (C1, 7
15) is the threshold value register 3 (Nmax1, 1843)
If it is larger, the overflow of the counter 3 (C1, 715) is passed to the latter stage 185 of the leaky bucket. The internal operation of the leaky bucket rear stage 185 is the same as that of the leaky bucket front stage 184. That is,
When receiving the notification of the overflow of the leaky bucket former stage 184, the arithmetic unit 721 sets the counter register 4 (C
2, 725), the addition value register 4 (Nadd
2, 1851). Counter register 4
(C2, 725) is the threshold value register 4 (Nmax2,
1853), the overflow detector 7
24 notifies the regulating unit 17 of an excess of declared traffic of the average burst length. The parameter of the leaky basket first stage 184 is determined to monitor the burst length based on the determination scale of h (retention time) shown in FIG. Therefore, the ratio between the addition value 3 and the subtraction rate 4 is set small. The parameters at the stage after the leaky bucket 185 are determined so as to monitor the average band based on the determination scale of h (reservation time) shown in FIG. Therefore, the ratio between the added value 4 and the subtraction rate 4 is set to be large. Next, if m (the number of waiting rooms) is determined with reference to FIG. 6 from the viewpoint of the accuracy of the detection of excess traffic, the added value 3, the subtraction rate 3, the squeeze 3, and the added value 4, the subtraction rate 4, the squeal value 4 are determined.

In FIG. 7, the leaky bucket front stage and the leaky bucket rear stage are configured independently, but the registers 715, 725, 1841, 1842, 1
Portions other than 843, 1851, 1852, 1853
Both can be common.

FIG. 8 and FIG. 9 show the multi-stage structure 2 in FIG.
5 shows an example of a change in a counter of two leaky bucket mechanisms. 8 shows a case where the average burst length is short, and FIG. 9 shows a case where the average burst length is long. (A) in FIG.
81, (a) 91 in FIG. 9 shows the arrival of the cell over time, and (b) 82 in FIG. 8 and (b) 92 in FIG.
The counter register 3 (C1, 7
(C) 83 in FIG. 8 and (c) 93 in FIG. 9 indicate changes with time in the counter register 4 (C2, 725) of the latter stage 185 of the leaky bucket, respectively. Show.

8 (b) 82 and 9 (b) 92 in FIG.
According to the determination scale of h (hold time) in FIG. 5, when the burst length is used as a monitoring parameter, this corresponds to a change in the counter of the leaky bucket mechanism having a one-stage configuration. Here, (b) 82 in FIG. In both cases of (b) 92 in FIG. 9, an overflow has occurred. In contrast, (c) 83 in FIG. 8 and (c) 93 in FIG.
9 (b) and 9 (b) due to the difference in the average burst length.
One cell arrival has been identified. That is, at (a) 91 in FIG. 9, the cells arrive as a burst in a short time, and the counter of the leaky bucket mechanism 83 in the preceding stage in which h (reservation time) in (b) 92 in FIG. C1 overflows in response to the burst, and FIG.
The counter C2 of the leaky bucket mechanism 84 at the subsequent stage where h (reservation time) of the middle (c) 93 is lengthened overflows due to a long-term monitoring result of the occurrence of the burst.

Next, referring to FIG. 1, the regulating portion 1 in FIG.
7 will be described.

First, the operation at call setup will be described. FIG.
As shown in block 1006 in the flow chart of 0, at the time of call setup, the regulation period length for which the regulation period length is determined by referring to the declared traffic parameter shown in the call setup signal is in the regulation unit 17 Is set in the regulation period length register 172. At the same time, the regulation unit 17 is initialized. When the initial setting of the regulating unit 17 is completed, the discard switch 174
The terminal 176 is connected to the terminal 175 so that an input from the information link 112 is output to the traffic monitor unit 18.

The time during the communication after the call is set up and the communication is started is divided into two cases, the restricted period and the non-regulated period. Terminal 176 in discard switch 174 in FIG.
However, the time connected to the terminal 175 is a non-regulation period, and the time connected to the terminal 177 is a non-regulation period. Therefore, immediately after the call setting, the non-regulation period is set as described above.

Next, the operation during the non-regulation period will be described with reference to FIG. In FIG. 1, the information cell sent from the terminal 11 to the exchange 12 via the information link 112 is:
After being received by the cell receiving unit 16, it is sent to the discard switch 174 in the regulating unit 17. As described above, since the terminal 176 in the discard switch 174 is connected to the terminal 175 during the non-regulation period, the received cell is
It is sent to the monitor 18. In this way, only the cells that have passed through the discard switch and are not regulated are subject to monitoring by the traffic monitor unit 18.

Next, similarly with reference to FIG. 1, the operation at the time of transition from the non-regulated period to the regulated period will be described. When the frequency of cell arrival exceeds the declared traffic level, the traffic monitor unit 18 notifies the regulation control unit 171 that the received traffic has exceeded the declared traffic. Upon receiving the notification, the regulation control unit 171 reads the regulation period length set at the time of the initial setting from the regulation period register 172, and registers the timer 173 with the timer so that the regulation control unit 171 is activated after the regulation period length has elapsed. At the same time, the discard switch 174 is set and the terminal 176 is connected to the terminal 177.
Belong to.

Next, the operation during the regulation period will be described with reference to FIG. During the restriction period, the output of the empty cell generator 178 is output to the traffic monitor 18. Therefore, the traffic monitor unit does not monitor the received information cell. The information cell transmitted from the terminal 11 via the information link 112 and received by the cell receiving unit 16 is discarded by the cell discard switch 174.

Next, similarly with reference to FIG. 1, the operation at the time of shifting from the regulation period to the non-regulation period will be described. When the timer 173 activates the regulation control unit 171 after the regulation period length has elapsed,
The regulation control unit sets a discard switch, and connects the terminal 176 to the terminal 175. That is, the cell received from the terminal 11 received by the cell receiving unit 16 is output to the switch 15 via the traffic monitoring unit 18, and the restricted period ends and shifts to the non-restricted period.

FIG. 11 is a diagram showing an example of arrival of cells that have exceeded the declared traffic. Hereinafter, it will be described with reference to FIG. 11 that the amount of regulated cells can be adjusted by setting the regulation period length.

In FIG. 11, the regulation period starts when the cell G arrives, and the cells arriving during the regulation period thereafter are discarded as described in FIG. In FIG. 11, 3
This shows a case where two different restriction period lengths are set, and the restriction period length is set to the restriction period I1 from the shorter restriction period length.
102, regulation period II 1103, regulation period III 110
4 indicates the range. When the restriction period I1102 is set, four cells from cell H to cell K are restricted and discarded. When the restriction period II 1103 is set, eight cells from cell H to cell O are restricted and discarded. When the restriction period III1104 is set, 12 cells from cell H to cell S are restricted and discarded. That is, as the set value of the regulation period length is larger, more cells are regulated, and as the set value of the regulation period length is smaller, fewer cells are regulated. Therefore, the ratio of cells to be regulated can be adjusted by setting the regulation period length.

FIG. 12 is a conceptual diagram showing the relationship between the restriction mechanism 17 and the traffic monitor mechanism 18 shown in FIG. When the frequency of arrival of the reception cell 1201 increases and the excess of the declared traffic is detected, the monitor mechanism 1203 notifies the regulation mechanism 1202 of the traffic excess detection at a frequency according to the excess detection frequency 1207 specific to the monitor method.
In the regulation mechanism 1202 that has received the notification, the amount of cells proportional to the set regulation period 1206 is regulated, and the monitoring target of the monitoring mechanism is reduced. That is, the traffic excess detection notification from the monitoring mechanism to the regulation mechanism functions as a feedback loop 1205. Therefore, the desired traffic amount of the output cell 1208 can be determined by setting the excess detection frequency 1207 and the restriction period 1206.

FIG. 13 is a diagram showing an example of arrival of cells that have exceeded the declared traffic when the detection frequencies of the traffic excess of the monitoring mechanism are different. Hereinafter, FIG.
The setting of the regulation period length in accordance with the traffic excess detection frequency specific to the regulation mechanism will be described with reference to FIG. As shown in FIG. 6, an appropriate value is selected for the traffic excess detection frequency depending on the trade-off relationship with the traffic excess detection accuracy, and therefore takes different values depending on the parameters of the traffic monitor. In FIG. 13, (a) 1301 is a monitor mechanism with a low excess detection frequency, (c) 1303 is a monitor mechanism with a frequent excess detection frequency, and (b) 1302 is a monitor mechanism with a low excess detection frequency (a) 1301 and (b). ) 1303, respectively. On the other hand, from the longest regulation period, (a) 1301,
The order is (b) 1302 and (c) 1303. As a result, the number of cells to be discarded is the same regardless of the difference in the traffic excess detection frequency specific to the monitor mechanism. As to which cells are discarded, (a) 130
1, (b) 1302, and (c) 1303 are different, and (a) 1301, (b) 1302, (c) 1303
In this order, cell discarding is performed intensively. That is, conversely, it is also possible to set the pattern in which the cell is discarded by adjusting the restriction period length of the parameter of the restriction mechanism and the frequency of detecting excess traffic of the monitor mechanism.

In this embodiment, an example of discarding cells is described as a regulation, but the case of applying the marking is also
The same can be applied. In this case, the discard switch 174 shown in FIG.
The monitor unit 18 may exclude the marked cell from the monitoring target.

FIG. 14 is a diagram showing an internal configuration when the average burst monitoring unit is realized by using an arrival number counter.

In FIG. 14, the average burst length monitoring unit 140
4 has two arrival number counters 1405, 1406. At the time of call setup, in the first stage of arrival number counter 1404, the parameters determined by the exchange control unit based on the traffic report parameters indicated in the call setup signal are stored in the parameter setting unit 1
The data is accumulated in the key value register 14055 through the line 4053. At the same time, the counter register 3 (C1, 1405
6) is cleared to zero. After the communication is started, the arithmetic unit 14051 operates the threshold value register 14055 and the counter register 3 (C1, 14056). That is, when a cell is input to the switch 1403 from the restricting unit 1401, the calculating unit 14051 increments the counter register 3 (C1, 14056). When activated by the timer 14052 at regular intervals, the overflow detection unit 14054 compares the counter register 3 (C1, 14056) with the threshold register 3 (Nmax1, 14056). If (C1, 14056) is larger than the threshold value register 3 (Nmax1, 14055), the counter 3 (C1,
14056). The internal operation of the post-arrival counter 1406 is as follows:
Same as 405. That is, the first stage of the arrival number counter 1
The arithmetic unit 1 receives the overflow notification from the
4061 is a counter register 4 (C2, 14056)
Is incremented. Counter register 4 (C2,
14066) is the threshold register 4 (Nmax2, 14)
065) is larger than the restriction unit 1401,
Notification of excess declared traffic of average burst length. A small value is set in the threshold value register 3 (Nmax1, 14055), and a large value is set in the threshold value register 4 (Nmax2, 14065).

FIG. 17 shows an example of changes in the counters of the two arrival number counters of the multi-stage configuration shown in FIG. That is, at (a) 1701 in FIG. 17, cells arrive as a burst in a short time, and
Arrival number counter previous stage 1 in the previous stage where the threshold value of 02 was shortened
The counter C1 at 405 overflows in response to the burst, and the counter C2 at the latter stage of the arrival number counter 1406 after the threshold value of (c) 1703 in FIG. 17 is increased due to the long-term monitoring result of the occurrence of the burst. ing.

FIG. 15 is a diagram showing an internal configuration in the case where the average burst monitoring unit is realized by using an arrival interval measuring device.

In FIG. 15, the average burst length monitoring unit 150 is shown.
4 has two arrival interval measuring devices 1505, 1506. At the time of call setting, the arrival interval measuring device upstream stage 1504 determines the parameters determined by the exchange control unit based on the traffic report parameters indicated in the call setting signal, by the parameter setting unit 1.
The data is stored in the threshold value register 15055 through the 5053. At the same time, the counter register 3 (C1, 150
57) is cleared to zero. After the communication is started, the operation unit 15051 operates the threshold value register 15055, the operation result register 3 (Asub1, 15056), and the counter register 3 (C1, 15057). That is, when a cell is input from the regulating unit 1501 to the switch 1503, the arithmetic unit 15051 calculates the counter register 3 (C1, 15
057), and subtraction result register 3 (Asu)
b1, 15056) and the counter register 3
The value of the timer 15052 is set in (C1, 15057). Subsequently, the overflow detection unit 15054 compares the subtraction result register 3 (Amax1, 15056) with the threshold value register 3 (Nmax1, 15055).
When the subtraction result register 3 (Asub1, 15056) is larger than the threshold value register 3 (Nmax1, 14055), an overflow of the subtraction result register 3 (Asub1, 15056) is notified to the subsequent stage 1506 of the arrival interval measuring device. The internal operation of the latter stage of the arrival interval measuring device 1506 is as follows.
This is the same as the preceding stage 1505 of the arrival interval measuring device. That is,
Upon receiving the notification of the overflow from the arrival interval measuring device front stage 1505, the arithmetic unit 15061 subtracts the value of the counter register 4 (C2, 15067) from the value of the timer 15062, and the subtraction result register 4 (Asub2, 1506).
6), and set the counter register 4 (C1, 1506).
In 7), the value of the timer 15062 is set. Subsequently, the overflow detection unit 15064 sets the subtraction result register 4 (A
sub2, 15066) and threshold register 4 (Nma
x2, 15065), and the subtraction result register 4 (Asub2, 15066) is compared with the threshold register 4
If it is larger than (Nmax2, 14065), the control unit 1501 is notified of the excess of the declared traffic of the average burst length. Threshold register 3 (Nmax1, 150
55) has a small value in threshold register 4 (Nmax).
2, 15065) is set to a large value. Therefore, when the cells arrive as a burst in a short period of time, the counter C1 of the preceding arrival interval measuring device 1505 which shortened the threshold value overflows in response to the burst, and the arrival number counter of the latter stage which increases the threshold value. The counter C2 in the subsequent stage 1506 overflows according to the monitoring result of the interval of occurrence of the burst.

FIG. 16 is a diagram showing an internal configuration in the case where the average burst monitoring unit is realized by using an arrival number counter and an arrival interval measuring device.

In FIG. 16, the average burst length monitoring unit 160
4 is an arrival number counter 1605 and an arrival interval measuring device 160
It has six. The internal operation of the arrival number counter 1605 is as follows.
This is the same as the arrival number counter 1405 in FIG. The internal operation of the arrival interval measuring device 1606 is the same as that of the arrival interval measuring device 1506 in FIG. Threshold register 3
A small value is set in (Nmax1, 16055), and a large value is set in threshold register 4 (Nmax2, 16065). Therefore, when the cells arrive as a burst in a short time, the counter C1 of the arrival number counter 1605 in the preceding stage, which has shortened the threshold value, overflows in response to the burst, and the subsequent arrival number counter in the latter stage increases the threshold value. Counter C2 of 1606
Overflows depending on the result of monitoring the interval between occurrences of bursts.

It is also possible to realize a multi-stage average burst length monitoring unit by using a frequency monitoring mechanism other than the leaky bucket, arrival number counter, and arrival interval measuring device described above.

[0055]

The leaky bucket mechanism at the preceding stage of the multi-stage leaky bucket mechanism overflows when packets collectively pass in a short time.
A short-term event such as when a cell arrives as the burst is detected and output to a leaky bucket mechanism at a subsequent stage. The leaky bucket mechanism at the subsequent stage monitors the occurrence frequency of a short-term event called passage of the burst in a long term. As a result, it is possible to reduce the probability of erroneously recognizing that the frequency of cell passage as a burst is excessive due to an accidental factor.

When the monitoring mechanism notifies the traffic excess, the regulation mechanism starts the regulation period and regulates the cells arriving during the regulation period. Since the length of the restriction period is determined by the restriction period length, which is a parameter, the amount of cells to be restricted can be adjusted by setting the parameter of the restriction period length. Therefore, the ratio of cells subject to regulation can be set irrespective of the traffic excess detection frequency specific to the monitoring mechanism.

The cell regulated by the regulation mechanism is not counted as a reception cell by the monitor mechanism. That is, only when the traffic that passes without restriction is larger than the declared traffic, the monitor detects the excess of the traffic and the restriction of the restriction mechanism is started. When a monitoring mechanism that frequently detects excess traffic is used for a certain amount of traffic that exceeds the declared traffic, the restriction period including the small number of cell arrivals is performed many times by setting a short restriction period length. Regulation takes place in the form. When a monitor mechanism that rarely performs excess detection is used, the regulation is performed in such a manner that the regulation period including a large number of cell arrivals is performed a small number of times by setting a long regulation period length. As a result, the traffic of unregulated passing packets can be set to a desired size irrespective of the monitor-specific excess traffic detection frequency.

Further, since the regulated cells are not monitored by the monitor mechanism, it is possible to detect the excess of the cells passing through without being regulated by the monitor mechanism from the traffic declaration traffic. At this time, by setting the regulation period length in accordance with the traffic excess detection frequency specific to the monitor mechanism, it is possible to set the traffic of cells passing without regulation to a desired size.

By incorporating these devices in the switching system, more stable and highly efficient packet switching can be realized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an ATM exchange according to an embodiment of the present invention.

FIG. 2 is a diagram showing a graph of a change in a counter of a leaky bucket mechanism.

FIG. 3 is a schematic diagram of a leaky bucket mechanism as a queue system.

FIG. 4 is a diagram showing traffic types to be monitored in an ATM exchange;

FIG. 5 is a diagram showing a scale for determining a parameter h (hold time) of a leaky bucket mechanism.

FIG. 6 is a diagram showing a scale for determining a parameter m (the number of waiting rooms) of the leaky bucket mechanism.

FIG. 7 is an internal configuration diagram of an average burst length monitoring unit 183 in FIG. 1;

FIG. 8 is a graph showing a change in a counter of a multi-stage leaky bucket mechanism.

FIG. 9 is a graph showing a change in the counter of the multi-stage leaky bucket mechanism.

FIG. 10 is a flowchart of a process for the subscriber circuit 14 when the exchange control unit 13 in FIG. 1 receives a call setting signal.

FIG. 11 is a diagram showing an example of arrival of a cell exceeding declared traffic and a restriction period.

FIG. 12 is a conceptual diagram illustrating a relationship between a regulation mechanism and a traffic monitoring mechanism in FIG. 1;

FIG. 13 is a diagram showing an example of the arrival of a cell exceeding the declared traffic and a restriction period.

FIG. 14 is an internal configuration diagram of an average burst length monitoring unit configured by an arrival number counter.

FIG. 15 is an internal configuration diagram of an average burst length monitoring unit configured by an arrival interval measuring device.

FIG. 16 is an internal configuration diagram of an average burst length monitoring unit including an arrival number counter and an arrival interval measuring device.

FIG. 17 is a graph showing a change in the counter of the multi-stage arrival number counter mechanism.

[Explanation of symbols]

11 --- Terminal 111 --- Subscriber Line Signal Link 112 --- Subscriber Line Information Link 12 --- ATM Switch 13 --- Exchange Control Unit 14 --- Subscriber Circuit 15 --- Subscriber Circuit Control unit 16 --- Cell receiving unit 17 --- Regulator 171 --- Regulator control unit 172 --- Regulatory period length register 173 --- Timer, 174 --- Discard switch 175, 176, 177 --- Terminal 178 --- empty cell generator 18 --- traffic monitor 181 --- maximum bandwidth monitor leaky bucket 182 --- average bandwidth monitor leaky bucket 183 --- average berth and length monitor 184- --Leaky bucket front stage 185 --- Leaky bucket rear stage 1811,1821,1831,1841 --- Addition value register 1812,1822,1832,1842 --- Subtraction value register 1813,1823,1833,1843 --- Shiki value register 19 ---switch

Claims (8)

[Claims] 1. A packet communication system comprising at least one input path and connecting a packet input from the input path to an appropriate output path among a plurality of output paths, the traffic of the packet input from the input path. Monitor the traffic, compare the traffic with a predetermined threshold value, and if the threshold value is exceeded, a monitor device that issues an excess notification; A packet control device that controls a packet that is input within a controlled period, and a connection device that connects a packet that is not controlled by the packet control device among the input packets to an output path that should output the packet. A packet communication system comprising: 2. The packet communication system according to claim 1, wherein the packet control device is arranged in front of the monitor device with respect to a packet input, and a packet controlled by the packet control device is monitored by the monitor device. A packet communication system characterized by being excluded. 3. The packet communication system according to claim 1, wherein the control period of the packet control device is set long for a monitor device that frequently detects excessive traffic, and for a monitor device that rarely detects excessive traffic. A packet communication system characterized by being set short. 4. An input means for inputting a packet from the outside, a traffic control means connected to the input means for controlling the traffic of the input packet according to a certain condition and outputting the packet, and the traffic control means Connection means for connecting the output packet to a path different from the input path; and a plurality of monitoring means for monitoring packet traffic within different monitoring times, respectively, wherein the traffic control means comprises the plurality of monitoring A packet communication system, characterized in that the traffic is controlled based on a monitoring result of any one of the means. 5. An input unit for inputting a packet from the outside, a traffic control unit connected to the input unit for controlling the traffic of a packet input according to a certain condition and outputting the packet, and the traffic control unit. Connection means for connecting the output packet to a path different from the input path; first monitoring means for monitoring packet traffic within a first monitoring time at a monitoring point in the packet communication system; Second monitoring means for monitoring packet traffic within a second monitoring time different from the first monitoring time, wherein the traffic control means controls the traffic based on a monitoring result of any one of the monitoring means. A packet communication system characterized by controlling. 6. An input unit for inputting a packet from the outside, a traffic control unit connected to the input unit for controlling the traffic of a packet input according to a certain condition and outputting the packet, and the traffic control unit. Connection means for connecting the output packet to a path different from the input path; first monitoring means for monitoring the maximum bandwidth of the traffic; and second monitoring means for monitoring the average bandwidth of the traffic. , And the traffic control means controls the traffic based on a monitoring result of either the first monitoring means or the second monitoring means. 7. An input device for inputting a packet from the outside, a traffic control device connected to the input device for controlling the traffic of a packet input according to a predetermined condition, and outputting the packet, the traffic control device comprising: A connection device that connects the output packet to a route different from the input route, a first leaky bucket that monitors the maximum bandwidth of the traffic, and a burst length monitoring device that monitors the burst state of the traffic, A second leaky bucket for monitoring the average bandwidth of the traffic, wherein the traffic control device includes the first leaky bucket,
A packet communication system, characterized in that the traffic is controlled based on a monitoring result of either a burst length monitoring device or a second leaky bucket. 8. A packet communication system comprising at least one input path and connecting a packet input from the input path to an appropriate output path among a plurality of output paths, wherein the packet input to the packet communication system is An arithmetic unit configured to connect a plurality of stages in series to perform an arithmetic operation based on the arithmetic result of the arithmetic unit, a burst traffic monitoring device for monitoring burst traffic based on the arithmetic result of the arithmetic unit, and the burst traffic monitoring device And a switching switch for switching and connecting a packet input to the input path to an appropriate output path based on the monitoring result of 1., in the arithmetic unit, the first arithmetic operation among the arithmetic means arranged in series. The number of packets input from the input path is input to the means, and the operation means immediately after the second stage from the head is input. Packet communication system, characterized in that inputs the operation result of the calculation means outputs the output of the arithmetic means of the final stage as the operation result of the arithmetic unit.