JPH08107421A - Method and device for measuring flow rate of cells - Google Patents

Abstract

PURPOSE: To unnecessitate a high-speed operation by respectively setting a specified cycle for each cell class at an n-fold unit cycle and delaying the reset of a cell count value just for prescribed time within a wrong unit cycle corresponding to the cell class. CONSTITUTION: A header information extracting part 60 extracts the header information of an arriving cell and outputs a VPI signal and a relevant VP timing signal. A cell number counter 61 reads the number of cells in an arriving VP from a cell number counter value memory 673. After '1' is added to this value, it is returned to the memory 673 and the number of cells in the arriving cell VP is updated. A VPI generating part 665 successively generates all the VPI within minimum time tmin and repeats this operation in the cycle of tmin. These specified number (n) of times of generated VPI, counter values of (n) times and cell number counter value are respectively read from memories 675, 676 and 673 to a correspondent circuit inside a T cycle reset part 66. Based on these values, a counter 667 performs reset processing once the (n) times within the minimum cycle tmin concerning the cell number counter value of the relevant VP.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cell flow rate measuring method and apparatus for measuring the cell flow rate of a polishing circuit in ATM (asynchronous transfer mode).

[0002]

2. Description of the Related Art B-ISDN (Broadband-Integrated S
ervices Digital Network) ATM (Asy
In the "nchronous Transfer Mode" technology, the "policing technology (or UPC: Usage Paraneter)" is used to control the cell flow rate by judging whether the ATM cell flow rate from the subscriber to the network exceeds the subscriber's declaration. Control)
) ”Is required.

In policing, an inflow cell is observed for each VP (Virtual Path) or VC (Virtural Call), and the observed cell flow rate is compared with the flow rate declared by the subscriber in advance to declare the declared flow rate. If the violating cell exceeds the limit, the cell is discarded or a violation is added.

FIG. 7A shows the structure of the polishing technique. In the figure, 1 is a policing circuit that monitors the cell flow rate for each VP / VC to control cell discarding and the like, and 2 is a control unit that controls the policing circuit 1 according to a value declared by a subscriber. The control unit 2 sets a value declared by the user to the policing circuit 1.

As shown in FIG. 7B, the polishing circuit 1 includes a cell information branching unit 3, a cell delaying unit 4, a cell control unit 5, a flow rate measuring unit 6 and the like. The cell information branching unit 3 branches the header information of the arriving cell, and the flow rate measuring unit 6 measures the cell flow rate in VP / VC units based on this header information and determines whether it violates the declaration. To do. The cell delay unit 4 is a circuit that adjusts the timing by delaying the arriving cells by the time required for the processing in the flow rate measurement unit 6, and the cell control unit 5 uses the cells input via the cell delay unit 4 as the flow rate measurement unit. If it is determined to be a violation according to 6, discarding or the like is performed, and if there is no violation, control is performed to pass it.

There are various methods for measuring the cell flow rate for determining whether or not the cell flow rate is in violation. FIG. 8 shows the various polishing methods. The various policing methods will be described below.

The "time interval method" measures the time interval t between the arriving cell and the previous arriving cell for each cell arrival, compares the measured value t with a predetermined prescribed value (allowable arrival time interval) T,
If it is smaller than this prescribed value T, it is a method of judging a violation.

The "TX method" counts the number x of cells arriving during a predetermined prescribed period T, compares the number x of cells with a predetermined prescribed number of cells X, and exceeds the prescribed number of cells X. If it is a violation, it is a method to judge.

In the "DB method", the count start points (phases) are sequentially shifted and the specified period T is counted in each phase, and the number x of cells arriving during the specified period T is specified period of all phases. T is counted, and the number of arriving cells x in each of the prescribed periods T is determined by a prescribed prescribed cell number X.
Compared with the above, if the number of cells exceeds the prescribed number X, it is a method of determining a violation.

The "CAT-M method" measures the time t at which (X + 1) cells arrive for all phases (every cell arrival), compares this time t with a prescribed time T, and If it is smaller than T, it is a method of judging a violation.

The "LB method" integrates the number of inflowing cells (adds a fixed number of counters every arrival of one cell), and subtracts a fixed amount of cells at a fixed speed from the integrated value (subtracts the counter at an average rate). By doing so, when the number of additions is larger than the number of subtractions and the integrated value increases and exceeds a predetermined amount B, the inflow cell amount is determined to be excessive and a violation occurs.

FIG. 9 shows a structural example of a flow rate measuring section (also called a traffic measuring section) in the above-mentioned polishing circuit. This flow rate measuring unit is a case where the above-mentioned "TX method" is used as a polishing method. FIG. 10 (A)
As shown in, the "TX method" counts the number x of cells a that arrived within the time T, and determines whether or not the value x exceeds the prescribed number X, to determine the cell violation.

In FIG. 9, the flow rate measuring unit includes a header information extracting unit 60, a cell number counter 61, a specified time T storage unit 62, a T time counter 63, a specified number X storage unit 64, and a comparison calculation unit 65. It

The header information extraction unit 60 is a circuit for extracting header information such as VPI (VP identifier) from the header of the arriving cell. The specified time storage unit 62 is a memory that stores the specified time T in advance. The specified time T is a value in which the processing time of one cell (hereinafter, referred to as cell time) is a unit. T
The time counter 63 is a counter that counts each time a cell timing signal (which is periodically generated every one cell time) is input, counts time in cell time units, and the counter value is a specified time T. When the specified time T of the storage unit 62 is reached, a reset signal is sent to the cell number counter 61. The cell number counter 61 is a header information extraction unit 60.
Is a counter that increments the count value by 1 each time a timing signal upon arrival of a cell is input, and outputs the count value to the comparison calculation unit 65 as the number of cells x. The comparison calculation unit 65 compares the number of cells x with the specified number X from the specified number X storage unit 64.

The operation of this flow rate measuring circuit will be described below. The header information extracting unit 61 extracts V from the header of the arriving cell.
Header information such as PI is extracted. Each time the cell arrives, a timing signal is sent to the cell number counter 61 to count the number of cells. On the other hand, the T time counter 63 counts the specified time T, and when the specified time T is reached, a reset signal is sent to the cell number counter 61. Therefore, the T time counter 63 creates a T time interval,
Since the cell number counter 61 is reset at the cycle timing of T time, the cell number counter 61 sends the cell number x arrived within the T time to the comparison calculation unit 65. The number of cells x is calculated by the comparison calculation unit 65 by the prescribed number X storage unit 6
It is compared with the specified number X from 4 and the presence or absence of cell violation is determined by whether or not the number of cells x exceeds the specified number X.

[0016]

The above-mentioned cell flow rate measuring circuit is for one type of cell (1 VP), but a plurality of VP (for example, 256 types) cells flow on the actual hardware. All of these have an arbitrary specified time T and a specified number X as parameters for each VP, and are each independently subjected to policing. For example, FIG. 10B shows the operation concept when there are four types of VPs. As shown in the figure, there are four types of arriving cells (VP), a, b, c and d, and the prescribed times of the cells a, b, c and d are Ta, Tb, Tc and Td, respectively. There is.

In order to perform policing on each of these VPs, the flow rate measuring circuit shown in FIG.
A method of preparing the same number as P and operating them simultaneously can be considered. However, the number of simultaneously-connected VPs on the highway reaches, for example, 256 in actual use, and this method is not realistic because the scale of hardware becomes huge.

Therefore, there is a method in which only one piece of hardware such as a counter and an arithmetic unit is prepared, information for all VPs is stored in a memory, and when the cell arrives, the information of the corresponding VP is read from the memory for policing. Be proposed. Figure 11
Shows a flow rate measuring circuit in the TX method by this method.

In FIG. 11, the flow rate measuring circuit includes a header information extraction unit 60, a cell number counter 61, a prescribed number X storage unit 64, a comparison calculation unit 65, a T period reset unit 66 ', a memory 67' and the like. There is something. The T-cycle reset unit 66 'includes a VPI generation unit 661 and a specified time T holding unit 6
62, a T time counter 663, and a cell number counter value holding unit 664. In addition, the memory 67 'is for each VP
The memory 671 for storing the specified time T, the memory 672 for storing the T time counter value, and the cell number counter value 67 for each
A memory 673 for storing 3 and a memory 674 for storing a specified number X are provided.

The VPI generator 661 is a circuit for generating all VPIs (VP identifiers) within one cell time.
The T time counter 663 is loaded with the specified time T held in the specified time T holding unit 662 and performs up-counting or down-counting, and when the counting for the specified time T is completed, a reset signal is output to hold the cell number counter value. This is a circuit that resets the cell number counter value of the unit 664.

When performing policing on all VPs by this method, it is necessary to reset the cell number counter of each VP for every VP at the cycle of the prescribed time T of the VP, in addition to the processing of the input cells. Therefore, in the present flow rate measurement circuit, this is performed by the T cycle reset unit 66. That is,
The arrival cell is processed for a certain time of one cell time,
The cell number counter of the VP that has reached the specified time T in the remaining time of the cell time is reset.

To explain this resetting method, first, the cell number counter 61 reads the cell number of the VP for each cell arrival from the cell number counter value memory 673 and adds "1" to this, and then the cell number counter value again. Memory 67
The number of cells of the corresponding VP is updated every time a cell arrives. The VPI generating unit 661 sequentially generates VPIs of all VPs within one cell time.
The generation is repeated in a one-cell time period. When the VPI is generated by the VPI generating unit 661, the specified time T of the VP, the T time counter value, the cell number counter value x, and the specified value X.
Is read from the memory 67 and held in the corresponding specified time T holding unit 662, T time counter 663, cell number counter value holding unit 664, and specified number X storage unit 64.

Once the specified time T has been loaded, the T time counter 663 counts down from the specified time T every VPI occurrence (that is, every one cell time), and the count value of the cell number counter of the VP concerned. It is determined whether the time for resetting has arrived. That is, when the count value becomes “1”, it is determined that the specified time T has elapsed, a reset signal is sent to the cell number counter value holding unit 664, and the cell number counter value of the VP is reset to “0”. . If it is not time to reset, the updated T time counter value is updated to the T time counter value memory 672.
Return to. This operation is performed within 1 cell time for all VPIs, and the check / reset operation for all VPs is repeated in a 1 cell time period.

By the above operation, the cell number counter value of the VP can be reset for each VP every time the specified time T of the VP elapses. Further, as the processing of the arrival cell, it is possible to determine the presence or absence of a cell violation by comparing the number x of cells read corresponding to the VP with the specified value X read corresponding to the VP by the comparison calculation unit 65.

The check / reset operation for all the VPs described above must be performed within one cell time including the processing time of the arriving cell. For example, the number of VPs is 256
Assuming the above case, it is necessary to determine whether or not to reset each of the 256 VPs within one cell time, and to perform the reset if necessary according to the result. Therefore, in the worst case all 256 VPs
However, there may be a situation where the reset must be performed within one cell time. Therefore, such a method
Although extremely high-speed processing within the cell time is required, it is difficult to implement it because it is actually limited by the memory access speed and the like.

The present invention has been made in view of the above circumstances, and an object thereof is to enable policing for a plurality of cell types with a small hardware scale and without requiring high-speed processing. It is in.

[0027]

FIG. 1 is a diagram illustrating the principle of the present invention. In the figure, 101 is a cell number counter, 102
Is a cell type generation means, 103 is a cell number storage means, 104
Is a magnification storage means, 105 is a number of times storage means, and 106 is a control means.

In order to solve the above problems, the present invention provides
Then, the specified cycle T is set to the unit cycle t for each cell type._minN
Set to double (where n is an integer of 1 or more) and set for each cell type
Cell that arrived while resetting the measured value at the specified period T
A cell flow rate measuring device for measuring the number of cells
Cell counter 101 for counting and unit cycle T_minWithin
Cell type delayed by a predetermined time according to the cell type
The identification signal is used as a unit cycle T _minCell type generation means generated in
102 and the number of cells counted by the cell number counter 101
Cell number storage means 103 for storing each type of cell, and a specified cycle
Magnification storage means 104 for storing the magnification n of T for each cell type
And a number-of-times storage means 105 for storing the number of times for each cell type.
The cell number counter 101 is equipped with a
The number of cells in the cell number storage means 103 is updated according to the cell type of
A new cell type identification generated by the cell type generation means 102.
Depending on the cell type of another signal, the number of
The number of times of the corresponding cell type in the stage 104 is updated, and the number is doubled.
It is the number of times of the multiplication factor n of the corresponding cell type in the rate storage means 105.
Then, the number of cells of the corresponding cell type of the cell number storage means 103 is set.
A cell flow meter configured to reset is provided.
Be done.

The cell type generating means described above is only for the cell type actually used among the plurality of cell types.
It is possible to output a valid cell type identification signal and perform reset process stop control for the remaining cell types.

The present invention also provides a cell flow rate measuring method in which a prescribed period T is set for each cell type, and the number of arriving cells is counted while resetting the count value at the prescribed period T for each cell type. , The specified period T for each corresponding type is set to n times the unit period t _min (where n is a positive integer of 1 or more), and the cell count value is reset within the unit period for a predetermined time period according to the cell type. There is provided a cell flow rate measuring method which is performed with each delay.

In the above-described cell flow rate measuring method, the cell count value can be reset for a plurality of cell types at one reset timing.

[0032]

The number of cells for each cell type (for example, VP or VC) is measured by the specified cycle (specified time) T of the cell type.
This is done by counting the number of cells of the cell type that has arrived in the counter. The count value of this counter is reset at each arrival timing of the prescribed cycle T, so that the number of cells is counted at each cycle. This operation is performed for each of the plurality of cell types.

The specified period T is different for each cell type,
Assuming that the minimum one of these prescribed periods T is a unit period (unit time) t _min , the prescribed period T for each cell type
Is expressed as T = n × t _min (where n is an integer of 1 or more).

Since this unit cycle t _min needs to be able to perform the check / reset processing for all cell types to be processed within the unit time, the time length is the time required for processing one cell ( That is, when the cell time) is used as a unit, the value is larger than the maximum number of cell types to be processed.

For one cell type, the unit cycle T
_minThe number of cells is counted each time
Whether the time to reset the data has arrived (that is, T =
n × t _minCheck whether or not the
If it is time to set, reset processing is performed (hereinafter,
This is called check / reset processing). Check this
Perform set processing for all cell types that should be processed
However, the execution time is a predetermined time for each cell type, for example, 1
Check / reset processing is performed because the cells are shifted by cell time.
The cell type to be processed is one cell type per cell time.
Limited, thus avoiding reset conflicts.

FIG. 2A shows four cell types.
An operation example in the case of different a, b, c and d is shown. cell
For types a, b, c, and d, the prescribed period T is Ta = 1 respectively.
× t _min, Tb = 2 × t_min, Tc = 4 × t_min, Td
= 3 × t_minAnd unit time t_minWithin
Check / reset processing timing (○ in the figure)
Or *) is shifted by 1 cell time. Reset process
The unit time t_minDo this every time
Fixed time T = n × t_minReset process for cell type
Is once in n check / reset processing times
Will be done. In FIG. 2A, each cell type
The other items a to d are re-marked at the circle marked with the beginning of the specified period T.
Set the row, and then check the cell type a
The cell type b is set once every time the processing timing arrives.
, Cell type c every 3 times, cell type d every 2 times
Perform a reset. * In the figure is the part where the reset is skipped.
is there.

The predetermined time (for example, one cell time)
The number of cell types in which the check / reset processing is performed is not limited to one type. If there is time, check for more than 2 cell types within 1 cell time.
The reset process may be performed. The operation in the case of the two-cell type is shown in FIG.

When one cell type is processed at the same time, the unit time t _min needs to be larger than the maximum number of cell types to be processed, but when two cell types are processed simultaneously, The unit time t _min may be a value larger than half the maximum number of cell types to be processed.

The cell flow rate measuring device of the present invention uses the above method.
To achieve this, the cell number counter 101
The cell number storage means 103 according to the cell type each time it is worn
The number of cells that arrived is counted by updating the number of cells in
I do. Then, under the control of the control means 106, the cell type is generated.
Cell type of cell type identification signal generated by live means 102
In accordance with the
Update the number of times for each type. The cell type generation means 102 is
Unit cycle t for one cell type_minCell type identification for each
Since a separate signal is output, the number of times is defined according to the cell type.
Period T = n × t _minUnit period t at_minWhat cycle of
It means that you have entered. Therefore, the number of times
The number of times of the magnification n of the corresponding cell type in the storage unit 105 has been reached.
Then, the reset time of the specified cycle T of the cell type has arrived.
It is determined that the cell type of the corresponding cell type of the cell number storage means 103
Reset the number of cells.

As described above, the check / reset processing for all cell types must be performed at different times within the unit cycle t _min . For this reason, in a system in which a large number of cell types are prepared, the unit cycle t _min becomes large and the check / reset processing interval becomes long. Therefore, the cell type generating means 101 is
Only a cell type that is actually used among a large number of cell types outputs a valid cell type identification signal, and reset processing stop control is performed for the remaining cell types. As a result, when there are many cell types themselves, but the cell types actually used are some of them, the minimum value of the cycle to be reset (that is, the unit cycle t _min ).
Can be made smaller.

[0041]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 shows a cell flow rate measuring device as an embodiment of the present invention. This embodiment uses the "TX method" as a polishing method. Header information extraction unit 6 in the figure
0, the cell number counter 61, the specified number X storage unit 64, and the comparison operation unit 65 are the same as those described in the section of the related art.

The T cycle reset unit 66 is a VPI generation unit 66.
5, a prescribed number n holding unit 666, an n-time counter 667, and a cell number counter value holding unit 664. The memory 67 includes a memory 675 that stores a specified number of times n, an n times counter value memory 676 that stores an n times counter value, and a memory 67 that stores a cell number counter value for each VP.
3, a memory 674 for storing the specified number X is included.

In this embodiment, the prescribed time T of each VP is set to T = n × t _min . However, n is a positive integer of 1 or more, and t _min is the minimum time of the specified time T of each VP. This minimum time t _min is set larger than the maximum number of VPs. That is, t _min ≧ maximum multiplex VP number. The above conditions are set.

The VPI generating unit 665 is a circuit that generates all VPIs to be processed by shifting them by one cell time within the above-mentioned minimum time t _min , and repeats this at a cycle of the minimum time t _min . That is, the check / reset processing timing (here, the timing of VPI generation) is generated for each VP at a cycle of t _min . The minimum time t _{mi n}
When the maximum VPI value is generated in, the check / reset processing is not performed for the remaining time. FIG. 5 shows how this VPI is generated. As shown, VP
When the maximum number of I is "m", V from "0" to "m"
When PI is generated, it is inactive for the rest of the time.

FIG. 4 shows a structural example of the VPI generating section 665. In the figure, 71 is a counter that increments the count value by 1 from "0" at each cell timing, 72 is a VP maximum value holding unit that holds the VP maximum value m, and 73 is a t _min holding unit that holds the minimum time t _min. , 74 and 75 are comparison parts. In this circuit, the counter 71 increments the count value by “+1” at each cell timing (every one cell time), and
Output as PI value. This count value (VPI value) is VP
When the maximum value m is reached, it is detected by the comparison unit 74 comparing it with the maximum value m of the VP maximum value holding unit 72, and a reset process stop control signal is output. Therefore a valid VPI
, VPIs of "0" to "m" are output. The operation of the counter 71 is performed until the count value reaches t _min , and t
_When it reaches _min , the comparing unit 75 detects it by comparing it with the value of the t _min holding unit 73, and resets the counter 71. Therefore, the generation of VPI of "0" to "m" is repeated in the cycle of the minimum time t _min .

The specified number of times n is a magnification of t _min of the above specified time T, and the specified number of times n is stored in the memory 675 for each VP. n times counter 66
7 is loaded with the prescribed number n of the corresponding VP from the prescribed number n holding unit 666, and thereafter, the prescribed number n is sequentially down-counted by using the counter value memory 676 for each check / reset processing timing of the relevant VP. And then n
It is a circuit that generates a reset signal when the counter value reaches "0". The cell number counter value holding unit 664 reads the cell number counter value of the cell number counter value memory 673 when the reset signal is input from the n-time counter 667,
This is a circuit for setting this to "0" and returning it to the same memory 673, that is, a circuit for resetting the number of cells.

The operation of the apparatus of this embodiment will be described below.
The header information extraction unit 60 extracts the header information of the arrived cell and outputs the VPI signal and the corresponding VP timing signal. The cell number counter 61 indicates that the V
The number of cells of P is read from the cell number counter value memory 673, "1" is added to the value, and then the value is returned to the memory 673 again.
The number of P cells is updated.

In the VPI generating section 665, the minimum time t _min
All VPIs (0 to m here) are generated in sequence,
This is repeated at a cycle of t _min . This generated V
The prescribed number n of PIs, the counter value n times, and the cell number counter value are read from the respective memories 675, 676, and 673 into the corresponding circuits in the T-cycle reset unit 66.

Based on these values, the n-time counter 667 resets the cell number counter value of the corresponding VP once every n times of the minimum period t _min . For example, when the n-time counter 667 is configured as a down counter, the counter value is decremented by 1 from the n-time counter value each time the VPI of the corresponding VP is input, and if the value becomes “0”, the number of cells of the corresponding VP is decreased. The counter value is reset, and the specified number of times n holding unit 666 causes the n times counter 667.
To the specified number of times n. Then, the n-time counter value and the cell number counter value are returned to the memories 676 and 673.
By this operation, the cell number counter is reset once every n times.

According to this method, it is only necessary to perform the check / reset processing for one VP within one cell time, and all VPs within one cell time as in the conventional circuit.
It is not necessary to update the specified time counter value for

In this embodiment, the n-time counter is constructed by using the down counter, but of course, it may be constructed by using the up counter to count the specified number of times n. Further, as an example, the case where the cell type is divided by the VP has been described, but it goes without saying that the cell type may be divided by the VC or the like. Further, in the above-described embodiment, the case where the check / reset processing of 1VP per cell time is performed has been described, but the present invention is not limited to this.
Of course, if there is a margin in the processing time within one cell time, the check / reset processing may be performed for a plurality of VPs within one cell time.

FIG. 6 shows another embodiment of the present invention.
It is another example of the configuration of the VPI generation unit of the above-mentioned cell flow rate measuring device. In this embodiment, even if there are a plurality of VPs on the highway, only the VPs that are actually used are reset, and the VPs that are not used are not reset. By storing the necessity / unnecessity of resetting of the VPI and reading the information of the necessity / unnecessity of resetting for the VPI from the counter 71, it is possible to control not to reset the unused VP.

As another configuration, the same VPI conversion unit is replaced with information indicating whether reset is necessary or unnecessary, and mapping is performed so that an input address and an actually used VPI are associated with each other. This makes it possible to reset only the VP that is actually used. For example, as the VPI, 256 kinds of VPI represented by 8 bits are used. However, when 16 kinds of VPI are actually used at the same time, 16 kinds of VPI to be used for the counter value “0 to 15” of the counter 71.
The PIs are made to correspond to each other, and the counter value "0 to 1"
5 ”, the VPI value is read from the VPI conversion unit 77. Further, “15” corresponding to 16 ways is put in the usage counter threshold value, and when the counter value of the counter 71 becomes “15”, the comparison unit 74 causes the OR circuit 78 to be used.
By sending the reset processing stop control signal via the, it is possible to reset only any 16 out of 256 VPs. By using this method, the minimum period t _min can be reduced to the value of the counter threshold (up to 16 in this example).

The above embodiments have been described with respect to the case where the present invention is applied to the cell flow rate measurement of the polishing method by the "TX method", but the present invention is not limited to this, of course.
It can be applied to a general policing method in which a prescribed period is measured for each cell type and the reset processing of the number of cells is performed.

[0055]

As described above, according to the present invention,
When performing the check / reset processing of a plurality of cell types, the check / reset processing within a predetermined time (for example, within one cell time) can be limited to one or a small number of cell types. It is not necessary to perform a high-speed operation such as performing check / reset processing for all cell types, and policing of a plurality of cell types can be realized with a small hardware scale.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is an explanatory view of the operation of the present invention.

FIG. 3 is a diagram showing a cell flow rate measuring device as an embodiment of the present invention.

FIG. 4 is a diagram showing a configuration example of a VPI generation unit in the device of the embodiment.

FIG. 5 is a diagram for explaining a mode of VPI generation in the apparatus of the embodiment.

FIG. 6 is a diagram illustrating another configuration example of a VPI generation unit.

FIG. 7 is a diagram illustrating a conventional polishing circuit.

FIG. 8 is a diagram illustrating various methods of policing.

FIG. 9 is a diagram showing a conventional example of a cell flow rate measuring circuit by the TX method.

FIG. 10 is a diagram showing an operation example of the TX method.

FIG. 11 is a diagram showing an example in which the hardware scale of the cell flow rate measurement circuit by the TX method is reduced.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 policing circuit 2 control part 3 cell information branching part 4 cell delay part 5 cell control part 6 cell flow rate measuring part 60 header information extracting part 61 cell number counter 62 specified time T storage part 63 T time counter 64 specified number storage part 66, 66 'T-cycle reset unit 67, 67' memory 661, 665 VPI generation unit 664 cell number count value holding unit 666 specified number holding unit 667 n times counter 673 cell number counter value memory 674 specified number X memory 675 specified number n memory 676 n times counter value memory

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical indication location H04Q 3/00 (72) Inventor Yoichi Sato 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Inventor Kan Toyoshima 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation

Claims (4)

[Claims] 1. A specified period (T) is set for each cell type,
A cell flow rate measuring method for counting the number of arriving cells while resetting the count value for each cell type at a specified cycle, wherein the specified cycle for each cell type is n times the unit cycle (t _min ). (n is an integer of 1 or more), and the cell count value is reset by delaying the cell count value by a predetermined time depending on the cell type within the unit cycle. 2. The cell flow rate measuring method according to claim 1, wherein the cell count value is reset for a plurality of cell types at one reset timing. 3. The specified period (T) is set to n times the unit period (t _min ) (where n is an integer of 1 or more) for each cell type, and the measured value is reset at the specified period for each cell type. A cell flow rate measuring device for measuring the number of cells arriving while a cell number counter for counting the number of cells and a cell type identification signal delayed by a predetermined time according to the cell type within the unit cycle Cell type generation means for generating in a unit cycle, cell number storage means for storing the number of cells counted by the cell number counter for each cell type, and magnification storage means for storing a magnification n of the specified cycle for each cell type. A cell number counter for updating the number of cells in the cell number storage means according to the cell type each time a cell arrives, and the cell type generation means. Cell type identification signal generated in The number of times of occurrence of the corresponding cell type in the number-of-times storage means is updated each time it occurs, and when the number of times reaches the number of times of the magnification n of the corresponding cell type of the magnification storage means, the number of cells is stored. A cell flow rate measuring device configured to reset the number of cells of the corresponding cell type of the means. 4. The cell type generation means outputs a valid cell type identification signal only for a cell type that is actually used among a plurality of cell types, and performs reset process stop control for the remaining cell types. The cell flow rate measuring device according to claim 3, wherein.