JPH09162897A - Policing controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate revision control of a parameter by simplifying configuration for delay control in the available bit rate service. SOLUTION: The policing controller is made up of a cell information branch section 1, a cell delay section 2, a cell control section 3, a flow measurement section 4, a parameter storage section 5, a backward resonance magnet B-RM cell detection section 6, and a delay control section 7. The delay control section 7 obtains a time from the passing of the B-RM cell till the arrival of the user cell based on a difference between a passing time of the B-RM cell detected by the B-RM cell detection section 6 and the user cell arrival time by the user cell information branched from the cell information branch section 1. Then the time and the maximum value and minimum value of delay reference are compared by a time comparison section 10 and a parameter switching control signal corresponding to the comparison result is fed to the parameter storage section 5 to control parameter revision processing. Furthermore, the parameter storage section 5 has two parameter regions, which are selected by a flag.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ATM (Asynchr
The present invention relates to a policing control device in an onous transfer mode). B-ISDN (Broadband-Integrate
A key technology of d Services Digital Network)
In the TM, the policing technique (or the usage parameter control (UPC) controlling the cell flow rate by judging whether or not the flow rate of the user cell flowing from the user terminal into the ATM network exceeds the value declared by the user. ; Usage Parameter
Control technology) is essential.

In this policing technique, each virtual path (VP; Virtual Path) or virtual channel (V
C; virtual channel) and the like, the flow rate of the user cell is measured for each connection, and this flow rate is compared with the flow rate declared by the user in advance, and for the violating cell, cell discard or addition of a violation tag is performed. . As a congestion control method in ATM, ABR (Available Bit Rat) is used.
e) method is known. The service based on this ABR method is such that the user terminal sets the minimum cell rate (MC
R: Minimum Cell Rate) and peak cell rate (PCR; Peak Cell Rate) are declared, and data is sent based on this parameter, but the network allows the user terminal to have an allowable rate (ACR; Allowed). Cel
l Rate) is sequentially instructed to be changed. In policing in the ABR system, policing is performed on the ACR that changes successively.

[0003]

2. Description of the Related Art FIG. 7 is an explanatory view of congestion notification. 51 is a user's transmitting terminal, 52 is a user's receiving terminal, 53, 5
Reference numeral 4 denotes switches (SW1, SW2) such as an ATM exchange, and the ATM network is configured by including these switches 53, 54. Further, (A) shows a congestion notification method by forward notification, and (B) shows a congestion notification method by backward notification.

A user cell is transmitted from the transmitting terminal 51, and the RM (R
esouce Management) A cell is inserted. Receiving terminal 5
Upon receipt of this RM cell, the 2 sends it back.
In this case, the RM cell transmitted from the transmitting terminal 51 side to the receiving terminal 52 side is an F-RM cell (Forward RM Cell).
), And the RM cell transmitted from the receiving terminal 52 side to the transmitting terminal 51 side is a B-RM cell (Backward RM Cel).
l).

FIG. 8 is an explanatory diagram of the format of the RM cell. In the header, the bit labeled GFC / VPI is the User Network Interface (UNI)
When used as a flow control GFC,
When used as a node interface (NNI), it is used as part of the virtual path identifier VPI. Therefore, the virtual path identifier VPI has an 8-bit configuration for UNI and a 12-bit configuration for NNI. Further, VCI is a virtual channel identifier having a 16-bit structure, and PT is a payload type having a 3-bit structure. For example, "000" indicates a user cell without congestion, and "110" indicates an RM cell. Also CLP
Indicates a 1-bit cell loss priority display, and CRC indicates 8-bit header error control.

[0006] The 48-byte payload of the RM cell is a 1-byte RM protocol identifier RM PRO.
TOCOL ID and DIR (Direction) are direction indication bits, "0" indicates an F-RM cell, and "1" indicates a B-RM cell. In addition, BN (BackwardExplicit Congestion No.
tification) is a reverse congestion notification bit indicating a B-RM cell generated at a switch (SW) or a receiving terminal in an ATM network, and CI (Congestion Indication).
Is a congestion indication bit, NI (No Increase) is a cell rate non-increasing bit, and RA (Request Acknowledge) is A
Request acknowledgment bit, Re, not used in BR
s indicates an unused bit.

ER (Explicit Cell Rate) is an allowable cell rate of 2 bytes, CCR (Current Cell Rate).
Rate) is the current cell rate of 2 bytes, MCR (Min
imumCellRate) is the minimum cell rate of 2 bytes,
QL (Queue Length) has a 4-byte structure, and is a queue length not used in ABR, and SN (Sequence).
Number) is a 4-byte sequence number. Further, it includes an unused bit Res of 30 bytes + 6 bits and a CRC (cyclic code check bit) of 10 bits at the end.

When the transmitting terminal sends an F-RM cell, R
To the allowable cell rate ER of M cells, the peak cell rate PCR (Peak Cell Rate) declared by the user at the time of call setup
Set. The allowable cell rate A is added to the current cell rate CCR.
CR (Allowed Cell Rate) is set, and the minimum cell rate MCR is set to the minimum cell rate. When the transmitting terminal receives a B-RM cell, when the congestion indicator bit CI indicates no congestion and the non-incrementable bit NI indicates increase, a certain rule is set within a range not exceeding the peak cell rate. Therefore, the cell rate can be increased. When the congestion indicator bit CI indicates that there is congestion, the cell rate must be reduced according to a certain rule within the range not lower than MCR.

In the congestion notification method based on the forward notification shown in FIG. 7A, for example, when the switch 53 causes congestion, the switch 53 explicitly indicates the cell to be sent to the receiving terminal 52 side. Forward congestion indicator EFCI (Expli
The cit Forward Congestion Indication) bit is set to "1". At the receiving terminal 52, the user cell terminates, and for the F-RM cell, the transmitting terminal 5 as a B-RM cell with the congestion notification bit CI set to "1".
It is sent back to the 1 side. The transmitting terminal 51 is B with CI = 1.
-Receive the RM cell and indicate that there is congestion, so lower the sending cell rate. Thereby, congestion in the switch 53 can be avoided.

The congestion notification method by backward notification shown in FIG. 7B is similar to the above-mentioned case, when congestion indicated by a star occurs in the switch 53, the B-RM in the switch 53 is generated. The congestion notification bit CI of the cell is transmitted as "1". The transmission terminal 51 receives the B-RM cell with CI = 1, identifies the presence of congestion, and lowers the transmission cell rate. Alternatively, when congestion occurs, the allowable cell rate ER of the B-RM cell can reduce the transmission cell rate of the transmitting terminal 51 to be equal to or lower than the allowable cell rate ER.

FIG. 9 is an explanatory view of a conventional policing control device, in which 61 is a cell information branching unit, 62 is a cell delay unit,
63 is a cell control unit, 64 is a flow rate measurement unit, 65 is a parameter storage unit, and 66 is a B-RM cell detection unit. When the cell flow rate control is performed based on the value declared by the user as in the constant bit rate CBR service or the variable bit rate VBR service, the B-RM cell detection unit 6
6 is omitted, the declared value of the user is stored in the parameter storage unit 65, the VPI and VCI of the header of the user cell branched by the cell information branching unit 61 are identified, and V
The flow rate of the user cell corresponding to PI and VCI is measured and compared with the declared value stored in the parameter storage unit 65, and the user cell having the flow rate exceeding the declared value is discarded or violated by the cell control unit 63. Add tags. The cell delay unit 62 is for compensating a processing delay by the flow rate measuring unit 64 and the like and adding a cell to the cell control unit 63.

In the ABR service, the B-RM cell detector 66 detects the B-RM cell to the receiving terminal side, and if CI = 1, it indicates that congestion has occurred. To avoid this, the policing parameter stored in the parameter storage unit 65 is changed to control the flow rate of the user cell. In addition, the transmission rate of the cell is lowered at the transmitting terminal which has received this B-RM cell.

FIG. 10 is an explanatory diagram of the delay control of the conventional example, in which the above-mentioned B-RM cell is sent from the interface section 72 between the transmitting terminal 71 and the interface section 72 of the switch (ATM switch). The transmission terminal 71 that receives the B-RM cell changes the rate and sends the transmitted cell to the interface unit 72 by the time indicated by tsi on the route indicated by the chain line.

Therefore, the policing parameter in the switch of the interface section 72 is generally B-
It may be changed after the time tsi elapses after the RM cell is transmitted. However, this time tsi depends on the processing time of the B-RM cell in the transmitting terminal 71 and the transmitting terminal 7
Since the distance between 1 and the interface unit 72 may be different and may vary, it is impossible to fix this time tsi fixedly.

Therefore, the maximum value τ2 and the minimum value τ3 of this time tsi are set in the interface section 72 as delay reference values. For example, if the B-RM cell passes through the interface section 72 at time t0, the minimum value τ3 is obtained up to time t2, and the maximum value τ2 is obtained up to time t3. A between time t0 and t2, B between time t2 and t3, and time t
When time is divided into C after 3 and τ3 ≦ tsi ≦ τ2, the user cell at time A is BR
The parameter is not changed because it is not affected by the M cell.

At the next time B, it is not possible to determine whether the cell is affected or not affected by the B-RM cell. Therefore, when lowering the cell rate by displaying congestion such as CI = 1, as shown in (a),
Do not change the parameters. Further, when the cell rate is increased as in the case of congestion recovery where CI = 1 is changed to CI = 0, the cell rate is increased as shown in (b) because the control is in the direction in which the user cell is not discarded. To change the parameters. Further, at time C, all the user cells are affected by the B-RM cell, so even if the cell rate is lowered, as shown in (a),
Change the parameters.

Further, at time t1, B-RM of another connection
The cell passes, and the maximum value in this VP / VC is τ2 '
When set to. That is, the maximum value and the minimum value of the time tsi can be set to correspond to VP / VC.

As described above, in order to set the maximum value τ2 and the minimum value τ3 of the time tsi and perform the policing control, FIG.
The configuration shown in FIG. In the figure, 81 is a cell information branching unit, 82 is a cell delay unit, 83 is a cell control unit, 8
4 is a flow rate measurement unit, 85 is a parameter storage unit, and 86 is B-
RM cell detector, 87 delay controller, 88 maximum value τ2
, 89 is a counter for measuring the time of the minimum value τ3, and CLK is a clock signal.

In the B-RM cell detector 86, the B-RM
When the cell is detected, the counters 88 and 89 start counting the clock signal CLK. For example, FIG.
B-RM cell passes at time t0 of
When 9 starts counting, the count content of the counter 89 indicates the minimum value τ3 at time t2, and the minimum value elapsed signal is added from the counter 89 to the parameter storage unit 85. At time t3, the count content of the counter 88 shows the maximum value τ2, and the maximum value elapsed signal is added from the counter 88 to the parameter storage unit 65.

At this time, when the cell rate is decreased due to congestion occurrence, the parameter is changed by the maximum value elapsed signal, and when the cell rate is increased due to congestion recovery or the like, the parameter is changed by the minimum value elapsed signal. .

[0021]

The B-RM cell is a VP.
/ VC-compliant. Therefore, also in the above delay control, it is necessary to provide the counter 88 having the maximum value τ2 and the counter 89 having the minimum value τ3 for starting the counting of the clock signal CLK by the detection of the B-RM cell in correspondence with VP / VC. Therefore, there is a problem that the scale of the delay control unit 87 becomes very large.

Further, as shown in FIG. 10, the maximum values corresponding to a plurality of connections are different as shown by τ2 and τ2 ', and the passing times of the B-RM cells corresponding to these connections are different. As described above, the parameters may be changed at the same time. Similarly, the minimum value τ3 also differs depending on the connection, and when the passing times of the B-RM cells corresponding to the connections differ, there is a high possibility that the parameters need to be changed at the same time. As described above, when the parameter changes occur at the same time, there is a problem that the parameter change process requests collide with each other and stable policing control cannot be performed.

Further, the policing parameter has a structure of ten or more bytes including the allowable cell rate and the like, and it is necessary to rewrite it instantaneously when such a parameter changing process is performed. Therefore, it is conceivable to use a high-speed storage device or a storage device having a wide bus width, but it is difficult to realize either of them in terms of cost and circuit scale. It is an object of the present invention to simplify the configuration of delay control and facilitate parameter change control.

[0024]

A policing control apparatus according to the present invention (1) judges whether or not an arriving user cell is a violating cell on the basis of a parameter stored in a parameter storage unit 5, and controls the cell. In the policing control device that controls the flow rate of the user cell by changing the parameter according to the cell information, the passing time of the control cell in the backward direction is stored, and the difference between this passing time and the arrival time of the user cell is stored. The delay control unit 7 that obtains the time from the passage of the control cell to the arrival of the user cell, compares this time with a preset delay reference value, and performs change control of the parameters stored in the parameter storage unit 5. Is provided.

(2) Further, the delay control section 7 has a passage time storage section for storing the passage time of the control cell for each connection.

(3) Further, the delay control section 7 compares the time obtained by the difference between the passing time of the control cell and the arrival time of the user cell with the maximum value τ2 and the minimum value τ3 as the delay reference values. , If the time is smaller than the minimum value τ3,
There is provided a configuration for controlling the parameter change of the parameter storage unit 5 in accordance with the comparison result between the case where the minimum value τ3 is greater than or equal to the maximum value τ2 and the case where the maximum value is greater than or equal to τ2.

(4) Further, the delay control section 7 has a delay reference value register 11 in which the delay reference value is set for each connection.

(5) Further, the parameter storage unit 5 has at least two parameter areas for storing parameters, and also has an effective area flag indicating a parameter area for storing parameters used for calculation. The configuration is such that the parameter area storing the parameters used for the calculation is switched by changing

(6) Further, the parameter storage unit 5 has a size flag indicating the size relationship between the parameter value of the parameter region currently in use and the parameter value of the parameter region to be switched next and used, and the delay control unit When the parameter is changed by 7, the configuration is such that the change timing of the parameter is controlled by referring to the large / small flag.

(7) Further, based on the parameters stored in the parameter storage unit 5, it is determined whether or not the arriving user cell is a violating cell, and the parameter is changed according to the information of the control cell to change the user cell. In a policing control device for controlling the flow rate of, stores the time of adding a preset delay reference value to the passage time of the control cell in the backward direction, by comparing this time with the user cell arrival time,
It is possible to provide a delay control unit 7 that controls the change of the parameters stored in the parameter storage unit 5.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view of an embodiment of the present invention.
1 is a cell information branching unit, 2 is a cell delay unit, 3 is a cell control unit, 4 is a flow rate measuring unit, 5 is a parameter storage unit, and 6 is B-.
RM cell detector, 7 delay controller, 8 user cell arrival time register, 9 B-RM cell transit time register, 1
Reference numeral 0 is a time comparison unit, and 11 is a delay reference value register.

The cell information branching unit 1, the cell delay unit 2, the cell control unit 3, and the flow rate measuring unit 4 are connected to the virtual bus identifier V of the header of the user cell by the cell information branching unit 1 as in the conventional example.
The PI and virtual channel identifier VCI are extracted, the flow rate of the user cell corresponding to the connection is measured by the flow rate measuring unit 4, and the arrived user cell is determined based on the parameters such as the allowable cell rate stored in the parameter storage unit 5. It is determined whether the cell is a violating cell, and the cell control unit 3 discards the violating cell or adds a violation tag.

The delay control unit 7 also includes a B-RM cell detection unit 6
The transit time of the B-RM cell corresponding to the connection based on the VPI / VCI detected by is set in the B-RM cell transit time register 9, and the arrival time of the user cell corresponding to the connection based on the VPI / VCI is set to the user cell. It is set in the arrival time register 8 and B-in the time comparison unit 10.
The time from the passage of the B-RM cell to the arrival of the user cell is determined from the difference between the contents of the RM cell passage time register 9 and the user cell arrival time register 8, and the time and the delay reference value register 11 are set. The parameter switching control is performed by comparing with the maximum value τ2 and the minimum value τ3 of the delay reference value corresponding to the connection based on VPI / VCI.

FIG. 2 is an explanatory diagram of the delay control unit and the parameter storage unit according to the embodiment of the present invention.
Has a connection-corresponding area, and a large / small flag DF, an effective area flag YF, a new parameter effective flag SF, a parameter A area, and a parameter B area are formed in each area. The delay control unit 7 also includes a time counter 21, B
-RM cell passage time storage unit 22, B-RM cell passage time register 23, and user cell arrival time register 24
A subtraction circuit 25, a comparison circuit 26, and a delay reference value register 27.

The parameter A area and the parameter B area of the parameter storage unit 5 respectively store policing parameters, and a case of having two parameter areas is shown. However, parameter area switching frequently occurs. In this case, it is possible to form more than that, and at least two parameter areas are provided.

The effective area flag YF is, for example, "0".
Indicates that the parameter A area is the effective area, and that "1" indicates that the parameter B area is the effective area. Therefore, by changing the valid area flag YF from "0" to "1", the parameter A area can be switched to the invalid area and the parameter B area can be switched to the valid area. Therefore, the calculation unit that performs cell flow rate measurement, violation cell determination, etc., not shown,
The parameter is read from the parameter area shown as the effective area by the effective area flag YF and arithmetic processing is performed, and when the parameter is changed, it can be dealt with by changing the effective area flag YF. When rewriting the parameters, the parameters are written in the invalid area indicated by the valid area flag YF.

The large / small flag DF indicates whether the value of the parameter of the invalid area is larger or smaller than the value of the parameter of the valid area. For example, "1" indicates that the parameter of the invalid area is large. When it is “0”, it indicates that the parameter of the invalid area is small. The new parameter valid flag SF indicates whether or not there is a new parameter. “1” if the parameter in the invalid area is the new parameter, and “1” if the parameter in the invalid area is not the new parameter (B-RM).
It is set to "0" when the cell does not pass even once or when switching to the new parameter is completed).

The subtraction circuit 25 and the comparison circuit 26 of the delay control unit 7 constitute the time comparison unit 10 of FIG. 1, and the user cell arrival time register 24 corresponds to the user cell arrival time register 8 of FIG. The B-RM cell passage time register 23 corresponds to the B-RM cell passage time register 9 in FIG. The time counter 21 counts clock signals and indicates time, and corresponds to a clock. This timepiece is generally realized by hardware, but can also be realized by software.

Therefore, when the B-RM cell detection signal from the B-RM cell detection unit 6 (see FIG. 1) is added to the B-RM cell passage time storage unit 22, the contents of the time counter 21 at that time are set to B. It can be stored as the RM cell transit time. The B-RM cell passage time is stored for each connection and is updated to the B-RM cell passage time at that time when the next B-RM cell passes.

When a user cell detection signal including VPI / VCI information such as header information from the cell information branching unit 1 (see FIG. 1) is added to the B-RM cell transit time storage unit 22, the VPI / VPI / The B-RM cell passage time corresponding to the connection based on the VCI is read and set in the B-RM cell passage time register 23. Also, the user cell arrival time according to the contents of the time counter 21 is set in the user cell arrival time register 24 by the user cell detection signal.

Then, the subtraction circuit 25 subtracts the B-RM cell passage time from the user cell arrival time to obtain the time T from the passage of the B-RM cell to the arrival of the user cell. . This time T and the VPI / VCI set in the delay reference value register 27
Maximum value τ2 and minimum value τ3 for connection based on
And the comparison circuit 26 compares the time T with the minimum value τ3.
When it is smaller, the parameter switching control signal is not output, but when it is the minimum value τ3 or more and smaller than the maximum value τ2, or when it is the maximum value τ2 or more, the parameter switching control signal indicating each case is output.

FIG. 3 is a diagram for explaining the operation of the embodiment of the present invention, in which the B-RM cell passes at times t0 and t4, and at time t1.
The case where the user cell arrives at ~ t3 and t5 to t7 is shown. As described above, the B-RM cell passage time storage unit 22 stores the passage time of the B-RM cell corresponding to the connection, and the B-RM cells of the same connection are stored at the times t0 and t1. When passing, after the time t0 indicated by the time counter 21 is stored in the B-RM cell passage time storage unit 22, it is updated at the time t4 indicated by the time counter 21 at the time t4.

In the user cell arrival time register 24,
Times t1, t2, t indicated by the time counter 21
3, t5, t6, t7 are set in sequence, and for each setting,
The time from the passage of the B-RM cell corresponding to the connection of the user cell is read and set in the B-RM cell passage time register 23, and after the passage of the B-RM cell by the subtraction circuit 25 until the arrival of the user cell. T1 to T6 are required.

This time Ti (i = 1, 2, 3, ...)
And the maximum value τ2 and the minimum value τ3 corresponding to the connection set in the delay reference value register 27 are performed in the comparison circuit 26, and the parameter switching control signal corresponding to the comparison result is added to the parameter storage unit 5.

When passing through the B-RM cell, the passing time is stored in the B-RM cell passing time storage unit 22. Also B-
The RM cell detection unit 6 (see FIG. 1) writes the parameter as the information of the B-RM cell in the parameter storage unit 5. In that case, the valid area flag YF is checked and the invalid area (used for the calculation is used. Parameter is stored in the parameter area), and the size relationship between the parameter in the valid area (old parameter) and the parameter written in the invalid area (new parameter) is calculated. Old parameter ≧ new For parameters,
The size flag DF is set to "0", and when the old parameter is smaller than the new parameter, the size flag DF is set to "1" and the new parameter valid flag SF is set to "1".

When the user cell arrives, the arrival time is set in the user cell arrival time register 24, and the new parameter valid flag SF is checked. If the new parameter valid flag SF is "0", the new parameter is set. Since it does not exist, the effective area flag YF is checked, and the policing control is performed using the effective area parameter (old parameter).

When the new parameter valid flag SF is "1", the B-RM cell passage time register 23 reads the B-RM cell passage time corresponding to the connection of the user cell from the B-RM cell passage time storage unit 22. , The subtraction circuit 25 subtracts the B-RM cell passage time from the user cell arrival time to obtain the time Ti from the passage of the B-RM cell to the arrival of the user cell, and the comparison circuit 26 sets the delay reference value register. The maximum value τ2 and the minimum value τ3 of 27 are compared.

When the comparison result is Ti <τ3, the user cell has arrived within the period A in FIG. 7, and the user cell is not affected by the B-RM cell. Policing control is performed using parameters, and flag operation is not performed.

When τ3 ≦ Ti <τ2, it means that the user cell has arrived within the period B in FIG. 7, and the user cell is mixed with the case where it is affected by the B-RM cell and the case where it is not affected. It is a period, and in this case, the large / small flag D
F is checked, and if the size flag DF is “0” (the new parameter value is small, that is, the rate increases in this example), the effective area flag YF is inverted to validate the new parameter, The new parameter valid flag SF is set to "0". Thereby, for example, the policing control can be instantaneously switched to increase the cell rate. Further, the size flag DF is “1” (the new parameter value is large, that is, the rate is small in this example).
If so, the flag operation is not performed. Therefore, the policing control is performed with the old parameters.

When τ2 ≦ Ti, the period C in FIG.
In the case where the user cell has arrived at, and the new parameter valid flag SF is "1", the valid area flag YF is inverted and the new parameter valid flag SF is set to "0". Thereby, the policing control is performed by instantly switching to the new parameter. If the new parameter valid flag SF is "0", it means that the parameter has already been switched to the new parameter, and the parameter in the invalid area is not the new parameter, so the flag operation is not performed.

By the above-mentioned operation, the policing control by the parameter change including the delay control can be performed, and the parameter of the connection concerned is changed only when the user cell arrives, so that a plurality of connections can be handled at the same time. The parameter change of will not occur. Further, the present invention is not limited to the above-mentioned embodiment, but various additions and changes can be made. For example, the maximum value τ2 and the minimum value τ3 of the delay reference values are updated from the host device or the like corresponding to the connection. It can also be possible. The parameter storage unit 5 may have a configuration in which the parameter A area and the parameter B area are similar to the two-sided memory configuration.

FIG. 4 is an explanatory diagram of a delay control unit according to another embodiment of the present invention, in which 31 is a time counter, 32 is a B-RM cell passage time storage unit, 33 is an addition time storage unit, and 34 is a user cell. An arrival time register, 35 is an addition circuit, 36 is a comparison circuit, 37 is a delay reference value register, and 38 is an addition time register.

The addition time register 38 and the comparison circuit 36 constitute the time comparison unit 10 of FIG. 1, and the user cell arrival time register 34 corresponds to the user cell arrival time register 8 of FIG. 1 and corresponds to the B-RM. Cell passage time register 32
Corresponds to the B-RM cell passage time register 9 in FIG. The time counter 21 counts clock signals to indicate time, and can be a hardware clock or a software clock.

When the B-RM cell detection signal is added to the B-RM cell passage time storage unit 32, the time counter 3 at that time is displayed.
The time indicated by 1 is stored as the B-RM cell passage time, and the addition circuit 35 adds the value obtained by adding the maximum value τ2 set in the delay reference value register 37 and the value obtained by adding the minimum value τ3 to the addition time. When the user cell detection signal is stored in the storage unit 33, the time indicated by the time counter 31 at that time is stored in the user cell arrival time register 34, and the addition time corresponding to the connection based on the VPI / VCI of the user cell is stored. The contents of the storage unit 33 are read out and set in the addition time register 38, the contents of the addition time register 38 and the contents of the user cell arrival time register 34 are compared in the comparison circuit 36, and the parameters based on the comparison result. A switching control signal is output and added to the parameter storage unit.

FIG. 5 is a diagram for explaining the operation of another embodiment of the present invention. When the B-RM cell passes at time t0, the time t0 indicated by the time counter 31 at that time is passed to the B-RM cell passage time storage unit 32. And the addition circuit 35 adds the minimum value τ3 and the maximum value τ2 set in the delay reference register 37. That is, t0 + τ3 = ta, t0 + τ2 = tb
Is stored in the addition time storage unit 33 in association with the connection based on VPI / VCI.

When the user cell arrives at the next time t1,
The time t1 indicated by the time counter 31 at that time is stored in the user cell arrival time register 34, and ta and tb corresponding to the connection based on the VPI / VCI of the user cell are read from the addition time storage unit 33 and set in the addition time register 38. The comparison circuit 36 compares t1 with ta and tb. Similarly, when the user cell arrives at times t2 and t3, it is compared with ta and tb. In this case, t1
<Ta, t1 <ta, t2> ta, t2 <tb, t3>
The relationship is ta, t3> tb.

Therefore, according to the comparison result by the comparison circuit 36, for example, the flags DF, YF, S as shown in FIG.
The parameter can be switched by operating F or the like. That is, at time t1, the parameters are not switched, and at time t2, the cell rate is immediately increased when the cell rate can be increased, and the cell rate is not changed when the cell rate is decreased.
At time t3, the cell rate in the case where the cell rate is lowered is lowered.

Similarly, when the B-RM cell passes at time t4 and the user cell arrives at times t5, t6 and t7, t4 + τ3 = tc and t4 + τ2 = td are stored in the addition time storage unit 33, and By comparing tc and td with the arrival times t5, t6 and t7 of the user cell, the timing of parameter switching is controlled. Further, the addition time can be configured to store one or more for one connection, and in that case, the parameter storage unit also has one.
It is possible to have a configuration in which two or more parameters are stored for each connection.

FIG. 6 is an explanatory diagram of the transit time of the B-RM cell and the delay reference value. FIG. 6A shows the minimum delay reference value of the B-RM cell in the state where the cell rate can be increased. The figure shows a case where the cells pass through at intervals of τ3 or less, and (B) shows the maximum delay reference value τ when the cell rate is lowered.
The case where the vehicle passes at intervals of 2 or less is shown.

In FIG. 6A, the cell rate is AC.
In the state indicated by R (0), the B-RM cell passes at time tb (1), and after the minimum delay reference value τ3 has elapsed, the cell rate is increased to ACR (1), and at the next time tb (2). Then, after the B-RM cell has passed and the minimum delay reference value τ3 has elapsed, the cell rate is increased to ACR (2). In that case, as shown in the figure, the time t in the relationship of (tb (1) + τ3)> tb (2)
Even when the B-RM cell passes through b (2), this time tb
After the minimum value τ3 has passed from (2), the cell rate is set to ACR (1)
To ACR (2) as shown by the dotted line, but this is the case where there is no disadvantage to the user side.
The passing time of the M cell is kept at tb (1), and the cell rate is the cell rate ACR by the B-RM cell at time tb (2).
The cell rate ACR (0) can be immediately raised to (2). In this case, the passing time of one B-RM cell or the value obtained by adding the minimum value τ3 to this passing time may be stored.

In FIG. 6B, the cell rate is A
In the state of CR (0), the B-RM cell passes at time tb (1), and after the maximum delay reference value τ2 has elapsed, the cell rate is set to A
The cell rate is lowered to CR (1), the B-RM cell passes at the next time tb (2), and after the maximum value τ2 has elapsed, the cell rate is set to ACR (2).
In case of lowering to (tb (1) + τ2)> tb (2), time t
When a B-RM cell passes at b (2), time tb (1),
Each of tb (2) is stored, and the cell rate is reduced from ACR (0) to ACR (1) at the time of tb (1) + τ2, and tb (2) is also stored.
(2) Cell rate from ACR (1) to ACR at time + τ2
It can be lowered to (2). In this case, two B-RMs
Cell passing times tb (1), tb (2) or tb (1) + τ
2, the value of tb (2) + τ2 is stored.

Even in the case of passing the time-related B-RM cell shown in FIGS. 6A and 6B described above, there is no disadvantage to the user side due to the parameter switching of each embodiment of the present invention. It is possible to apply various policing control means.

[0063]

As described above, according to the present invention, the passage time of the control cell in the backward direction, that is, the B-RM cell is stored, and the difference between the passage time and the arrival time of the user cell is subtracted. The time calculated by the circuit 25 and the delay reference value (τ2, τ3) set in the delay reference value register 27 are compared in the comparison circuit 26, and the parameter is switched by the parameter switching control signal corresponding to the state of the comparison result. The parameter change control of the storage unit 5 is performed, and when the parameter change process is performed, since the user cells do not arrive at the same time when the user cells arrive, the parameter change processes occur simultaneously for multiple connections. There is nothing to do.

By configuring the B-RM cell passage time storage unit 22 to store the passage time corresponding to each connection, only one B-RM cell passage time register 23 and one user cell arrival time register 24 are required. Therefore, for example, the delay control unit 7 of the present invention reduces the circuit scale as compared with the delay control unit that obtains the maximum value τ2 and the minimum value τ3 of the delay control using the counter shown in FIG. There is an advantage that it is possible to do.

Further, the parameters stored in the parameter storage unit 5 can be changed by switching the parameters written in at least two parameter areas. Even if a plurality of effective area flags YF, large / small flags DF, and new parameter effective flags SF are provided, each of them has a 1-bit structure, and therefore, operations such as checking and reversing these flags are easy and quick. The advantage is that it is possible to perform stable policing control on ATM cells that perform high-speed transmission.

Further, the minimum value τ3 and the maximum value τ2 of the delay reference values are added to the passing time of the B-RM cell and stored, and the arrival time of the user cell is compared to make a comparison. There is an advantage that the processing speed can be increased.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a delay control unit and a parameter storage unit according to the embodiment of this invention.

FIG. 3 is an operation explanatory diagram of the embodiment of the present invention.

FIG. 4 is an explanatory diagram of a delay control unit according to another embodiment of the present invention.

FIG. 5 is an operation explanatory diagram of another embodiment of the present invention.

FIG. 6 is an explanatory diagram of a transit time of a B-RM cell and a delay reference value.

FIG. 7 is an explanatory diagram of congestion notification.

FIG. 8 is an explanatory diagram of a format of an RM cell.

FIG. 9 is an explanatory diagram of a conventional polishing control device.

FIG. 10 is an explanatory diagram of delay control of a conventional example.

FIG. 11 is an explanatory diagram of a policing control device in a conventional ABR service.

[Explanation of symbols]

 1 Cell Information Branching Section 2 Cell Delay Section 3 Cell Control Section 4 Flow Rate Measuring Section 5 Parameter Storage Section 6 B-RM Cell Detection Section 7 Delay Control Section 8 User Cell Arrival Time Register 9 B-RM Cell Passing Time Register 10 Time Comparison Section 11 Delay reference value register

Claims (7)

[Claims] 1. The flow rate of the user cell is determined based on the parameter stored in the parameter storage unit, whether or not the arrived user cell is a violating cell, and the parameter is changed according to the information of the control cell. In a policing control device for controlling, the passing time of the control cell in the backward direction is stored, and the difference between the passing time and the arrival time of the user cell causes the arrival of the user cell from the passage of the control cell. The polishing control apparatus is characterized in that a delay control unit is provided for controlling the change of the parameter stored in the parameter storage unit by calculating the time until the delay time is compared with a preset delay reference value. . 2. The policing control device according to claim 1, wherein the delay control unit includes a passage time storage unit that stores the passage time of the control cell for each connection. 3. The delay control unit compares a time obtained by a difference between a passing time of the control cell and an arrival time of the user cell with a maximum value and a minimum value as a delay reference value, A configuration for controlling parameter change of the parameter storage unit in accordance with a comparison result when the time is smaller than the minimum value, when the time is greater than or equal to the minimum value and smaller than the maximum value, and when the time is greater than or equal to the maximum value. The polishing control apparatus according to claim 1 or 2, further comprising: 4. The policing control apparatus according to claim 1, wherein the delay control unit has a delay reference value register in which the delay reference value is set for each connection. 5. The parameter storage unit has at least two parameter areas for storing the parameters, and also has an effective area flag indicating a parameter area for storing parameters used for calculation. 2. The policing control apparatus according to claim 1, further comprising a structure for switching a parameter area storing a parameter used for the calculation by changing a flag. 6. The parameter storage unit has a size flag indicating a size relationship between a parameter value of a parameter region currently in use and a parameter value of a parameter region to be switched next to be used, and The policing control apparatus according to claim 1 or 5, further comprising a configuration for controlling a parameter change timing when the parameter is changed by referring to the large / small flag. 7. The flow rate of the user cell is determined based on the parameter stored in the parameter storage unit, whether or not the arrived user cell is a violating cell, and the parameter is changed according to the information of the control cell. In the policing control device for controlling the, stores the time obtained by adding a preset delay reference value to the passage time of the control cell in the backward direction, by comparing the time and the user cell arrival time, the parameter A policing control device comprising a delay control unit for controlling a change of a parameter stored in a storage unit.