JPH09233088A - Cell traffic monitor system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a monitor system in which cell traffic is accurately monitored with a miniaturized timer counter and addition of a memory circulation means without addition of new information. SOLUTION: This system is configured by adding a memory circulation means 3 to a conventional cell traffic monitor system provided with a cell detection means 1, a timer counter 2, an arithmetic means 4, a memory 5, a comparator means 6, and an abort means 7. The memory circulation means 3 circulates various parameter data for each virtual path identifier/virtual channel identifier VPI/VCI number stored in the memory 5 synchronously with a cell synchronizing signal, replaces a packet count stored in the memory 5 with a packet count obtained by the arithmetic means 4 based on the preceding cell arrival time, the circulated time and the packet count and the preceding cell arrival time stored in the memory 5 is rewritten into the circulated time. The circulation is automonously conducted independently of a received ATM cell or a cell interval time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cell traffic monitoring system, and more particularly to an asynchronous transfer mode (Asynchronous Transfer Mode).
The present invention relates to a cell traffic monitoring system in which an ATM network using a Nose Transfer Mode (ATM), a subscriber declares the flow rate of ATM cells, and the network side monitors the flow rate of ATM cells based on the subscriber's declaration.

[0002]

2. Description of the Related Art In an ATM network, the flow rate of ATM cells is monitored on the basis of report parameters contracted between a subscriber and a network side, and the flow rate of ATM cells of a violating subscriber is limited to within a declared value. Therefore, a policing function for securing the communication quality of other subscribers is indispensable.

[0003] As one conventional example for realizing this policing function, there can be mentioned an algorithm described in paragraph numbers [0034 to 0038] of JP-A-4-329733, "Monitoring system for ATM transmission network".

As another conventional example, a TX method, a DB
(Dangerous Bridge) method and LB (Le
aky Bucket method).

FIG. 4 is a block diagram showing a conventional cell traffic monitoring system to which the LB method is applied.

Referring to FIG. 4, in this conventional cell traffic monitoring system, the cell detecting means 1 detects whether the received ATM cell is a valid cell or an invalid cell and VPI (Vir).
(Tual Path Identifier) / VCI
(Virtual Channel Identify
er) Identification of the number. When a valid cell is received, the arrival time of the ATM cell is referred to from the timer counter 2 and the corresponding VPI / VCI stored in the memory 5 is referred to.
It refers to the previous cell arrival time of the number, the bucket counter value, and the cell interval time (= 1 / cell transfer rate value).

The calculating means 4 calculates a bucket counter value based on the current cell arrival time, the previous cell arrival time, the bucket counter value and the cell interval time.

The operation result of the operation means 4 is compared with the traffic threshold value of the corresponding VPI / VCI number stored in the memory 5 by the comparison means 6, and if the traffic threshold value is exceeded, the discard means 7 outputs the ATM. The cell was discarded.

[0009]

The conventional policing algorithm has a problem in that new information such as flags and data must be added in order to solve the problems of the prior art. there were.

In another conventional cell traffic monitoring system, the prior art cell arrival time, bucket counter value, cell interval time, and VPI / VC of the traffic threshold value are used.
If the information for each I number is large, there is a problem that the number of required memories also increases. In addition, since the timer counter that refers to the arrival time of the ATM cell is a finite cyclic counter, the arrival time of the previous ATM cell and the If the time interval from the arrival time of the current ATM cell exceeds the range in which the time can be displayed, there is a problem that accurate measurement cannot be performed.

[0011] An object of the present invention is to provide a cell traffic monitoring system capable of accurately monitoring cell traffic by adding a memory circulating means, without adding new information, and reducing the size of a timer counter. To provide.

[0012]

According to the present invention, detection of valid / invalid cells of a received ATM cell and VPI
/ VCI number discriminating means, a timer counter for synchronizing with a cell synchronizing signal to generate an arrival time of the ATM cell and a time of circulating the memory by the memory circulating means, a previous cell arriving time and a bucket counter value For storing various parameter data such as cell interval time and traffic threshold value for each VPI / VCI number, the current cell arrival time, the time of circulating through the memory, and the VPI / VCI stored in the memory. Calculating means for calculating the buckets counter value from the various parameter data for each number; and a time interval between the current cell arrival time of the received ATM cell and the previous cell arrival time of the same VPI / VCI number as the timer counter. The previous cell for each VPI / VCI number held in the memory before exceeding a limit The memory circulating means for updating the arrival time and the bucket counter value; a comparing means for comparing the bucket counter value obtained by the arithmetic means with the traffic threshold value held in the memory; And a discarding means for discarding the received ATM cell when the cell is determined as a violating cell.

Further, the memory circulating means circulates all the VPI / VCI numbers from the VPI / VCI number 0 to the last number held in the memory and stores them in the memory before the limit of the timer counter is exceeded. The stored previous cell arrival time for each VPI / VCI number is updated to the circulating time, and the bucket counter value for each VPI / VCI number is updated to the previous cell arrival time, the circulating time, and the bucket counter. Based on the value, the bucket traffic value obtained by the calculating means is updated, and a cell traffic monitoring system is obtained.

Further, there is provided a cell traffic monitoring system wherein the memory circulating means autonomously circulates the memory irrespective of the received ATM cell and cell interval time.

Further, the memory circulating means circulates at least once through all the VPI / VCI numbers from 0 to the last number held in the memory before the timer counter makes one cycle. A cell traffic monitoring method characterized by the above feature is obtained.

[0016]

Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a cell counter monitoring method according to the present invention. FIG. 2 is a flowchart showing a traffic monitoring algorithm when a valid cell is received in FIG. 1. FIG. It is a flow chart which shows a memory patrol algorithm which performs overflow processing before exceeding the limit of a displayable range.

In FIG. 1, the components having the same functions as those of the conventional example among the components of the cell traffic monitoring system in the present embodiment are denoted by the same reference numerals as in FIG.

That is, the cell traffic monitoring system of the present embodiment has a configuration in which the memory circulating means 3 is added to the conventional cell traffic monitoring system.

The cell detecting means 1 detects a valid cell / invalid cell of the received ATM cell and identifies the VPI / VCI number.

The timer counter 2 is a finite cyclic counter for generating the arrival time of the ATM cell and generating the cyclic time of the memory 5 in synchronization with the cell synchronization signal.

The memory 5 holds various parameter data such as the arrival time of the previous ATM cell, the bucket counter value, the cell interval time (= 1 / cell transfer rate value) and the traffic threshold for each VPI / VCI number.

When a valid ATM cell is received, the calculating means 4 calculates a bucket counter value based on various parameter data of the corresponding VPI / VCI number stored in the memory 5 and the current cell arrival time, and performs a memory cycling. The means 3 calculates a bucket counter value based on the various parameter data of the corresponding VPI / VCI number circulated through the memory 5 and the circulated time.

The comparing means 6 compares the bucket counter value obtained by the calculating means 4 with the traffic threshold value stored in the memory 5.

The discarding means 7 discards the received ATM cell when the comparison result is determined to be a violation cell.

The memory circulating means 3 synchronizes with the cell synchronizing signal and circulates various parameter data for each VPI / VCI number held in the memory 5 and sends the bucket counter value held in the memory 5 to the previous cell. The value is rewritten to the bucket counter value obtained by the arithmetic means 4 based on the time, the circulating time and the bucket counter value, and rewritten to the time when the previous cell arrival time stored in the memory 5 is circulated. This cyclic operation is performed autonomously irrespective of the received ATM cell or cell interval time.

Next, the operation of this embodiment will be described with reference to FIGS.

FIG. 2 shows that the cell detecting means 1 detects whether an ATM cell is a valid cell or an invalid cell, and detects VPI / VC
9 shows a traffic monitoring algorithm after the identification of the I number is performed.

As shown in FIG. 2, the cell detecting means 1 receives a valid ATM cell, identifies the VPI / VCI number, acquires the current time Ta from the timer counter 2 (step S10), and Previous cell arrival time LCT which is various parameter data of the corresponding VPI / VCI number
, Bucket counter value CNT and traffic threshold value THR
And the cell interval time INT (= 1 / cell transfer rate value) (S11).

The bucket counter value CNT ′ = bucket counter value CNT− (current time Ta−previous cell arrival time LC)
T) is calculated (S12).

When the bucket counter value CNT 'is smaller than "0" (negative value) (YES in S13), the calculating means 4
To set the bucket counter value CNT 'to "0" (S14).

The bucket counter value CN is calculated by the comparing means 6.
T 'is compared with the traffic threshold value THR, and if the bucket counter value CNT' is larger than the traffic threshold value THR (YES in S15), the ATM cell received by the discarding means 7 is discarded (S16). finish.

If NO in S15, that is, as a result of the comparison by the comparing means 6, when the bucket counter value CNT 'is equal to or smaller than the traffic threshold value THR, the calculating means 4 sets the bucket counter value CNT = bucket counter value CNT' + cell interval. The time INT is calculated (S17), and the previous cell arrival time LCT is rewritten to the current time Ta (S1).
8) The bucket counter value CNT and the previous cell arrival time LCT are written in the corresponding VPI / VCI number area in the memory 5 (S19), and the process ends.

Next, as shown in FIG. 3, the memory tour is started by a trigger such as a power-on reset, irrespective of the received ATM cell and irrespective of the cell interval time INT.

When the memory patrol is started, the V of the memory 5 is
From the PI / VCI number “0” (S20) to the oldest one in turn, the previous cell arrival time L for each VPI / VCI number
Rewrite CT and bucket counter value CNT (S2
1, S22, ...).

This operation is performed up to the last number of the VPI / VCI number (S23). When the operation is completed, the process returns to S20 and the tour is performed again from the first "0". In this way, the circuit travels from “0” to the last.

This cyclic operation is performed irrespective of the received ATM cell and irrespective of the cell interval time INT, and before the timer counter 2 makes one cycle, the memory 5
Circulates at least once for all the VPI / VCI numbers held in.

Next, the operation of rewriting the previous cell arrival time LCT and the bucket counter value CNT in this memory cycle will be described.

When the VPI / VCI number "0" is cycled (step S20), the current time Ta when the circuit is cycled is obtained from the timer counter 2 (S24), and the cycled VPI / VCI number is read from the memory 5. The previous cell arrival time LCT and the bucket counter value CNT, which are various parameter data, are acquired (S25).

The bucket counter value CNT ′ = bucket counter value CNT− (current time Ta−previous cell arrival time LC)
T) is calculated (S26).

Here, when the bucket counter value CNT 'is smaller than "0" (YES in S27), the calculating means 4 sets the bucket counter value CNT' to "0" (S28).

At S28, the bucket counter value C is set.
After setting NT '= 0, or when NO in S27, that is, when the bucket counter value CNT'> 0, the arithmetic means 4
Is the bucket counter value CNT = bucket counter value CNT '
(S29), the previous cell arrival time LCT = current time Ta
(S210), and writes the bucket counter value CNT and the previous cell arrival time LCT into the memory 5 (S21).
1).

Next, the VPI / VCI number "1" is circulated (S21), and thereafter the same operation is sequentially performed on the oldest number.

In this embodiment, the memory traversal operation is performed as follows.
The VPI / VCI numbers are changed from "0" (S20) to the last number (S23) in ascending order.
The same effect can be obtained by traversing in ascending order.

[0045]

As described above, according to the present invention, detection of valid / invalid cells of received ATM cells and VPI / VPI
A cell detecting means for identifying a VCI number; a timer counter for synchronizing with a cell synchronization signal to generate an arrival time of an ATM cell and a time of circulating through a memory by a memory circulating means; A memory for holding various parameter data of an interval time and a traffic threshold for each VPI / VCI number, and a current cell arrival time, a time of cycling through the memory, and various parameter data for each VPI / VCI number held in the memory Means for calculating a buckets counter value from the memory, and a time interval between the current cell arrival time of the received ATM cell and the previous cell arrival time of the same VPI / VCI number is held in the memory before exceeding the limit of the timer counter. A memory circuit that updates the previous cell arrival time and bucket counter value for each VPI / VCI number Comparing means for comparing the bucket counter value obtained by the arithmetic means with the traffic threshold value held in the memory; and discarding means for discarding the ATM cell received when the comparison result is determined to be a violating cell. With this arrangement, the memory circulating means circulates through all the VPI / VCI numbers from 0 to the last number stored in the memory and stores them in the memory before exceeding the limit of the timer counter. The cell arrival time for each VPI / VCI number is updated to the circulation time, and the bucket counter value for each VPI / VCI number is obtained by the arithmetic means based on the previous cell arrival time, the circulation time, and the bucket counter value. By updating the value to the bucket counter value, the memory circulating means is further independent of the received ATM cell and cell interval time. Further, by autonomously circulating the memory in the memory, the memory circulating means further stores all the VPI / VCI numbers from 0 to the last VPI / VCI number held in the memory before the timer counter makes one cycle. By circulating at least once, there is an effect that the timer counter can be downsized and the traffic can be accurately monitored without increasing the information for each VPI / VCI number.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a cell counter monitoring method according to the present invention.

FIG. 2 is a flow chart showing a traffic monitoring algorithm when a valid cell is received in FIG.

FIG. 3 is a flowchart showing a memory traversal algorithm for executing an overflow process before exceeding a limit of a time displayable range of a timer counter in FIG. 1;

FIG. 4 is a block diagram showing a conventional cell traffic monitoring method to which a LB (leaky bucket) method is applied.

[Explanation of symbols]

 1 Cell detecting means 2 Timer counter 3 Memory circulating means 4 Computing means 5 Memory 6 Comparing means 7 Discarding means CNT, CNT 'bucket counter value INT Cell interval time LCT Previous cell arrival time Ta Current time THR Traffic threshold

Claims (4)

[Claims] 1. A cell detecting means for detecting a valid cell / invalid cell of a received ATM cell and for identifying a VPI / VCI number, and a memory by means of an arrival time of the ATM cell and a memory circulating means in synchronization with a cell synchronization signal. A timer counter for generating the circulating time, a memory for holding various parameter data such as a previous cell arrival time, a bucket counter value, a cell interval time, and a traffic threshold for each VPI / VCI number, and a current cell arrival time And the time at which the memory has traveled and the VP held in the memory
Calculating means for calculating the buckets counter value from the various parameter data for each I / VCI number; and VPI / V which is the same as the current cell arrival time of the received ATM cell
Before the time interval between the previous cell arrival time of the CI number and the timer counter exceeds the limit of the timer counter, the memory traversal for updating the previous cell arrival time and the bucket counter value for each of the VPI / VCI numbers held in the memory. Means,
Comparing means for comparing the bucket counter value obtained by the arithmetic means with the traffic threshold value stored in the memory; and discarding the received ATM cell when the comparison result is determined to be a violation cell. Means for monitoring cell traffic. 2. The memory circulating means circulates through all VPI / VCI numbers from 0 to the last VPI / VCI number stored in the memory and stores the VPI / VCI number in the memory before exceeding the limit of the timer counter. The VP holding
The previous cell arrival time for each I / VCI number is updated to the circulation time, and the bucket counter value for each VPI / VCI number is updated based on the previous cell arrival time, the circulation time, and the bucket counter value. 2. The cell traffic monitoring method according to claim 1, wherein the bucket counter value is updated by the calculation means. 3. The memory traversing means receives the received AT.
3. The cell traffic monitoring system according to claim 1, wherein the memory autonomously circulates irrespective of an M cell and a cell interval time. 4. The VPI held in the memory by the memory circulating means before the timer counter makes one cycle.
/ VCI / VCI numbers from 0 to the last number
4. The cell traffic monitoring system according to claim 1, wherein the CI number is circulated at least once.