JP3005553B1 - Test method and apparatus for AAL1-SAR function - Google Patents

Abstract

A test method and apparatus for determining which of a segmentation / reassembly function of an AAL1-SAR function block has a failure. AAL1-SAR function block (12)
The ATM cell is generated by dividing the data of the digital multiplex line, and the ATM cell is reassembled into the data of the digital multiplex line to perform the loopback test of the AAL1-SAR function. From the start to the end of the division, the number of data of the digital multiplex line is counted by the segmentation counter 103, and the number of ATM cells to be generated is calculated from the number of data. Further AAL1-SA
The number of ATM cells generated by the R function block is counted by the cell counter 104. A to be generated
A comparator 105 compares the number of TM cells with the number of generated ATM cells.
To determine the division function. The failure point can be easily determined by the loopback test and the division function test.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an AAL (ATM Adapta).
tion Layer: ATM adaptation layer) Type 1
The present invention relates to a method and an apparatus for testing a protocol SAR (Segmentation and Reassembly) function.

[0002]

2. Description of the Related Art Digital multiplex lines and ATM (Asynchroun)
ous Transfer Mode: AAL type 1 protocol SAR (hereinafter, A) for performing segmentation (division) and reassembly (assembly) with a cell line
Described as AL1-SAR. ) Various test methods for the normality of function have been proposed.

[0003] Test data is inserted into the digital multiplex line, and the data is transmitted to the ATM by the AAL1-SAR function.
After being segmented into cells, AAL1 is again returned by the cell loopback line provided on the ATM cell line side.
-Return to SAR function. The AAL1-SAR function checks again the data reassembled as a digital multiplexed line signal, and the AAL1-SAR
It is possible to test whether the function is operating normally.

[0004]

However, in the test method described above, the reassembled data is checked in order to perform the test by simultaneously operating the segmentation function and the reassembly function among the AAL1-SAR functions. When detecting a failure in the AAL1-SAR function, it is impossible to determine where the failure has occurred in the AAL1-SAR function.

An object of the present invention is to provide an AAL1-SAR function test method and apparatus which can easily determine where a failure has occurred in the AAL1-SAR function.

[0006]

According to the present invention, data of a digital multiplex line is divided by an AAL1-SAR function block to generate an ATM cell, and the ATM cell is divided by the AAL1-SAR function block into an ATM cell. The AAL1-SAR function loopback test is performed by assembling the data again, and the number of data of the digital multiplex line is counted from the start to the end of division by the AAL1-SAR function block, and is generated from the number of data. AAL1-S
ATM generated by AAL1-SAR function block between start and end of division by AR function block
AAL1-S is counted by counting the number of cells and comparing the number of ATM cells to be generated with the number of generated ATM cells.
A division function test of the AR function is performed.

[0007] From the results of the loopback test and the results of the split function test, it is possible to easily determine where a failure has occurred in the AAL1-SAR function.

[0008]

DETAILED DESCRIPTION OF THE INVENTION FIG.
It is a block diagram showing one embodiment of a SAR function test device. The AAL1-SAR function test apparatus is connected to the line
And AAL1-S provided between the ATM switch 13
A function test is performed on the AR function block 12. The line corresponding unit 11 is an external interface unit of a digital multiplex line. The ATM switch 13 distributes ATM cells input / output to / from the AAL1-SAR function block 12 to ATM cell lines.

The AAL1-SAR function block 12 includes a digital multiplexed line (U
P) is segmented (divided) into ATM cells, and the ATM switch 1 is switched through an ATM line (UP).
Output to 3. Conversely, ATM cells input from the ATM switch 13 are reassembled into digital multiplex line data and output to the line corresponding unit 11 by digital multiplex lines (DOWN).

The AAL1-SAR function test apparatus has a test data insertion unit 101 and a selector 102,
02 is inserted into the digital multiplexing line (UP) between the line corresponding unit 11 and the AAL1-SAR function block 12, selects one of the data input from the line corresponding unit 11 and the test data inserting unit 101, and selects AAL1- Output to the SAR function block 12. In other words, the selector 102
Can insert test data into any channel of a digital multiplex line (UP).

The AAL1-SAR function block 12 is a
Digital multiplexing line (UP) data into ATM cells
Segmentation start / end signal for segmentation
No. S _{S / T}To the segmentation counter 103 and the segmentation counter.
To the digital counter 104, and further to a digital multiplex line (U
P) Clock signal CLK indicating data transfer timing
Is output to the segmentation counter 103.

The segmentation counter 103 and the cell counter 104 correspond to the AAL1-SAR function block 1.
The counting operation is performed with the segmentation start / end signal S _{S / T} from 2 enabled. That is, the segmentation counter 103 counts the number of data flowing through the digital multiplex line (UP) according to the clock signal CLK, and compares the count value _CSEG with the comparator 105.
Output to Further, the cell counter 104 counts the number of cells flowing through the ATM cell line (UP) and outputs the count value C _CELL to the comparator 105. Comparator 10
The comparison result by No. 5 is output to the determination unit 106 as the segmentation function determination.

On the other hand, AAL1-
ATM cell line (DO) to SAR function block 12
WM), a selector 107 is inserted, and an ATM cell and an ATM cell line (DO) flowing through the ATM cell line (UP) are inserted.
WM) to select one of the ATM cells
1-Output to SAR function block 12. Therefore, the selector 107 selects the ATM cell line (UP) side, thereby changing the ATM cells of the ATM cell line (UP) to AAL1-AAL1.
It can be looped back to the SAR function block 12.

Further, the test data detecting section 108 is connected to a digital multiplex line (DOWN), and data is extracted from an arbitrary channel of the digital multiplex line (DOWN) to confirm the coincidence with the test data inserted for the test. I do. The detection result is output to determination section 106. The selector 1
02, the selector 107, the test data insertion unit 101, and the determination unit 106 are controlled by the control unit 109 of the test apparatus.

FIG. 2 shows AAL1-SAR according to the present embodiment.
5 is a signal time chart for explaining the operation of the function test device.

In general, a digital multiplex line is a data signal (FIG. 2C) composed of a set of channels divided in a specific unit (8 bits or the like) in synchronization with a frame signal. The frame signal FRM shown in FIG.
(B)) and a clock signal CLK (FIG. 2A) indicating data transfer timing.

The data signal of the digital multiplex line (UP) output from the line corresponding unit 11 is input to the AAL1-SAR function block 12 and assembled into an ATM cell.
At this time, the AAL1-SAR function block 12 monitors the frame signal FRM of the digital multiplex line (UP), fetches the data of the digital multiplex line at an appropriate timing on a channel basis, assembles it into ATM cells, and outputs it to the ATM switch 13. . AAL1-SAR function block 12
The start / end timing of the ATM cell assembling operation is determined by a segmentation start / end signal S _{S / T} (FIG. 2).
(D) is output to the segmentation counter 103 and the cell counter 104.

The segmentation counter 103
Fragmentation start / end signal S _{S / T}Enable
End after segmentation starts
Number of data flowing through the digital multiplex line (UP)
Are counted in accordance with the clock signal CLK (FIG. 2)
(E)).

On the other hand, the AAL1-SAR function block 12
The ATM cell output from is input to the ATM switch 13 through the ATM cell line (UP) (FIG. 2 (f)).
At this time, the cell counter 104 enables the segmentation start / end signal S _{S / T} (FIG. 2 (d)) to enable the segmentation start / end signal S _{S / T} (FIG. 2 (d)) to start reading the count value from the segmentation counter 103 after the segmentation is started. The number of ATM cells flowing to the (UP) is counted (FIG. 2 (g)).

The comparator 105 can determine the amount of data to be _cellized by using the count value _CSEG input from the segmentation counter 103, and further uses this amount of data to calculate the AAL1-SAR function block 12.
Can calculate the number of cells to be transmitted. The comparator 105 compares the calculated number of cells to be transmitted with the actually transmitted cell count value C _CELL input from the cell counter 104. The AAL1-SAR function block 1 is determined by whether or not the number of cells to be transmitted matches the actually transmitted cell count value C _CELL.
The normality of the segmentation function of the second ATM cell 19
Can be confirmed without directly verifying the data signal.

[0021] Also, A flowing through the ATM cell line (UP)
The TM cell is transferred to the ATM cell line (D
OWN), AAL1-SAR function block 1
Input to 2. AAL1-SAR function block 12
Performs the reassembly of the folded ATM cell and transmits it to the digital multiplex line (DOWN). That is, when the selector 107 selects the ATM line (UP),
Digital multiplexed line (UP) data is passed through a segmented / reassembled digital multiplexed line (DOW).
N).

Therefore, the test data detecting section 108 compares the test data inserted into an arbitrary channel by the test data inserting section 101 and the selector 102 with the data of the corresponding channel of the digital multiplex line (DOWN). , AAL1-SAR function block 12
Can test its segmentation / reassembly function.

As described above, the judgment unit 106 receives the judgment result of the segmentation function from the comparator 105 and the judgment result of the segmentation / reassembly function from the test data detection unit 108. Therefore, when a failure is detected by the test data detection unit 108 and the normality is confirmed by the comparator 105, it is understood that the reassembly function of the AAL1-SAR function block 12 has a failure.

When a failure is detected by the test data detection unit 108 and a failure is also detected by the comparator 105,
First, the AAL1-SAR function block 1 is restored by restoring the segmentation function and then performing the test again.
2 can confirm the normality of the reassembly function.

FIG. 3 is a block diagram showing another embodiment of the AAL1-SAR function test apparatus according to the present invention. However, the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

In the present embodiment, the ATM line (UP) of the AAL1-SAR function block 12 and the ATM switch 13
A cell filter 301 is inserted into the ATM cell line (U
Only the specific ATM cell of P) is selected and passed. The ATM cell that has passed through the cell filter 301 is output to the cell counter 104 and the selector 107.

A specific ATM is determined by the cell filter 301.
By allowing only the cells to pass, it becomes possible to test the normality of the segmentation function for any group of channels when the data of the digital multiplex line is divided into groups of a plurality of channels and segmentation is performed.

[0028]

As described above, according to the present invention, the normality of the segmentation function of the AAL1-SAR function block can be simplified by comparing the number of cells to be transmitted with the number of cells transmitted. You can check. Therefore, when a failure occurs in the AAL1-SAR function block, it is possible to easily determine which of the segmentation / reassembly functions has failed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an AAL1-SAR function test apparatus according to the present invention.

FIG. 2 is a signal time chart for explaining the operation of the AAL1-SAR function test device according to the present embodiment.

FIG. 3 is a block diagram showing another embodiment of the AAL1-SAR function test apparatus according to the present invention.

[Explanation of symbols]

 11 Line Corresponding Unit 12 AAL1-SAR Functional Block 13 ATM Switch 101 Test Data Insertion Unit 102 Selector 103 Segmentation Counter 104 Cell Counter 105 Comparator 106 Judge 107 Selector 108 Test Data Detection Unit 109 Control Unit 301 Cell Filter

Claims (6)

(57) [Claims] An AAL type 1 protocol SAR for dividing and assembling between a digital multiplex line and an ATM line.
(Hereinafter, referred to as AAL1-SAR.) In the test method of the functional block, the data of the digital multiplex line is stored in the AAL1-SAR.
The AAL1-SAR function is divided by the function block to generate an ATM cell, and the ATM cell is reassembled into the data of the digital multiplex line by the AAL1-SAR function block to perform a loopback test of the AAL1-SAR function. Count the number of data of the digital multiplexed line data from the start to the end of division by the block, calculate the number of ATM cells to be generated from the number of data, and start the division by the AAL1-SAR function block. Count the number of ATM cells generated by the AAL1-SAR functional block until the end, and calculate the number of ATM cells to be generated and the generated AT
A method for testing an AAL1-SAR functional block, wherein a division function test among the AAL1-SAR functions is performed by comparing the number of MAL cells with the number of M cells. 2. The method for testing an AAL1-SAR functional block according to claim 1, wherein a failure occurrence location is specified based on a result of the loopback test and a result of the division function test. 3. The AAL1-SAR according to claim 1, wherein only desired ATM cells are selectively passed through the ATM line, and the number of passed desired ATM cells is counted and looped back. Function block test method. 4. An AAL type 1 protocol SAR for dividing and assembling between a digital multiplex line and an ATM line.
(AAL1-SAR) a functional block test apparatus, comprising: first counting means for counting the number of data of the digital multiplex line from the start to the end of division by the AAL1-SAR functional block; Second counting means for counting the number of ATM cells generated by the AAL1-SAR function block between the start and end of division by the AAL1-SAR function block; and an ATM to be generated calculated from the data number. By comparing the number of cells with the number of generated ATM cells,
Division function determining means for determining a division function of the AAL1-SAR function;
The AAL1-S performs the AAL1-SAR function determination by dividing the function block into ATM cells and reassembling the ATM cells into the digital multiplex line data by the AAL1-SAR function block.
An AAL1-SAR functional block test apparatus, comprising: an AR function determining means. 5. The apparatus according to claim 1, further comprising a fault specifying unit for specifying a fault occurrence location based on a result of the determination by the split function determining unit and a result of the determination by the AAL1-SAR function determining unit. AAL1-SAR according to item 4
Test equipment for functional blocks. 6. An ATM line is provided with a cell filter for selecting and passing only desired ATM cells. The second counting means counts the number of ATM cells output from the cell filter. The SAR function determining means returns the ATM cell output from the cell filter to the AAL1
The AAL1-SA according to claim 4 or 5, wherein a SAR function is determined.
Test equipment for R function block.