JPH04124936A - Continuity testing system for exchange speech path - Google Patents

Abstract

PURPOSE:To confirm the normal operation of a speech path through a signal cell for a test by providing an ATM exchange speech path with a loop-back means, and connecting the generation circuit of a test cell connected to a specified incoming highway and the receiver of a testing device connected to a specified outgoing highway through the loop-back circuit. CONSTITUTION:The test cell generated by the test cell generating means 4 is looped back by the loop-back means 6 through the ATM exchange speech path 3, and is led to a test object route in the TAM speech path 3, and by detecting a VCI for a test in the arrival cell by a test cell receiving means 5, the continuity of the tested object route in the ATM speech path 3 is confirmed. The test cell generated by the test cell generating means 4 is outputted to one of the outgoing highways through the ATM exchange speech path 3 as long as the conductive line of the ATN exchange speech path 3 is normal, and the outputted test cell is looped back by the loop-back means 6 corresponding to the test object route, and is inputted again to the ATM exchange speech path 3, and is outputted to one of the outgoing highways through the test object route.

Description

[Detailed Description of the Invention] [Summary] Regarding a continuity test method for an ATM switching communication path, the present invention aims to easily conduct a continuity test of a path within an ATM switching communication path between multiple incoming highways and multiple outgoing highways. The ATM communication path for exchanging is connected to one of the human highways, and the test cell generating means for generating test cells containing the test VCI is connected to one of the outgoing highways for receiving test cells. A test cell receiving means, a test cell return means for returning only the test cells from the outgoing highway to an incoming highway paired with each outgoing highway, and an ATM.
A test path setting means is provided for forming a communication path for a test cell within the communication path, and the test cell generated by the test cell generation means is folded back by a test cell folding means,
The cell is guided to the test target route within the ATM communication path, and the test cell receiving means detects the test VCI in the arriving cell, thereby confirming continuity of the test target route within the ATM communication path.

[Industrial application field]

The present invention is an ATM (Asynchronous Tran)
sfer Mode) Concerning a continuity test method for switched communication paths, in particular, as a maintenance function in ATM exchanges, it is concerned with checking the normal operation of communication paths, confirming continuity in path connections at the time of call setup, and guaranteeing allocated bandwidth.

[Conventional technology]

In order to check the continuity of the communication path in general circuit switching, it is sufficient to send a signal to the time slot under test on the main highway and check the signal on the outgoing highway.
In order to check the continuity of the communication path during switching, each cell is input to the communication path asynchronously, so it is necessary to check the contents of the cells to determine the order in which the cells are sent and whether cells are being discarded or missing due to an increase in load. There is. Therefore, test equipment for continuity testing of ATM switching communication lines becomes complicated.

FIG. 8 is a diagram showing an example of a configuration for conducting a continuity test on a conventional ATM exchange channel. In the figure, for the sake of simplicity, four communication routes are shown for people's highways, and four communication routes are also shown for exit highways. Conventionally, as shown in FIG.
Test cell generating means 805 to 808 were connected to each of output highways 809 to 804, and test cell receiving means 813 to 816 were connected to each of output highways 809 to 812.

[Problem to be solved by the invention]

The above-mentioned conventional system has problems in that the number of test cell generating means and test cell receiving means is large, the amount of hardware is enormous, and the cost of the apparatus is high.

SUMMARY OF THE INVENTION An object of the present invention is to provide a continuity test method that reduces the amount of /S-ware in an ATM exchange channel.

[Means to solve the problem]

FIG. 1 is a block diagram of the principle of the present invention. In the figure, 1 is a plurality of people highways, 2 is a plurality of exit highways,
3 is an ATM communication path for performing exchange between the incoming highway 1 and the outgoing highway 20. According to the present invention, test V CI (
Virtual Channel Identifier
The test cell generating means 4 for generating test cells containing r) is connected to only one of the plurality of incoming highways 1, and the test cell receiving means 5 for receiving the test cells is connected to one of the plurality of outgoing highways 2. connected to only one of the Also,
Test cell folding means 6 for folding back test cells from the outgoing highway 2 is provided on the incoming highway paired with each of the outgoing highways 2. Further, a test path setting means 7 for forming a communication path for a test cell within the ATM communication path 3 is connected to the ATM communication path 3.

The test cell generated by the test cell generating means 4 is looped back by the turning means 6 via the ATM exchange channel 3, guided to the route to be tested within the ATM channel 3, and the arriving cell is received by the test cell receiving means 5. By detecting the test VCI within the ATM channel 3, continuity of the test target route within the ATM communication path 3 is confirmed.

The test cell generation means 5 is equipped with a means for controlling the frequency of test cell generation, generates cells corresponding to the path bandwidth allocation request, and connects the call after confirming that the corresponding path satisfies the service quality. is preferred.

[Effect]

The test cell generated by the test cell generating means 4 is outputted to one of the output highways via the ATM switching channel 4 as long as the conduction path of the ATM switching channel 3 is normal. is turned back by the turn-back means 6 corresponding to the route to be tested, is again manually inputted to the ATM switching communication path 3, passes through the route to be tested, and is routed to one of the outgoing highways. Next, this output test cell is turned back again by the turn-back means 6 corresponding to the test cell reception means 5, and is received by the test cell reception means 5. If there is a failure in the route to be tested, the test cell receiving means 5
Since no test cells are received, we know that there is a failure on that route.

Since the test cell generating means and the test cell receiving means, which were conventionally provided on each highway with a large number of people, are placed only on a specific one of the highways with a large number of people, the number of nodes can be greatly reduced.

〔Example〕

FIG. 2 is a block diagram showing the configuration of an ATM switching channel according to an embodiment of the present invention. In the same figure, 201 is AT
It is an M exchange communication path, and there are 4 people's 4 ways 202 to 2.
Exit the cell from any of the 05 highway 206
209. For this purpose, cell switches 210 to 225 each having a TAG determination section and a cell storage buffer are arranged in a matrix. A VCI (Virtual Cell
Identifier) TAG indicating exit highway
A conversion circuit (VCC) 226 is connected to convert the voltage into the voltage. Similarly, a conversion circuit (VCC) 227 is connected between the inputs of the cell switches 214 to 217 and the main highway 203, and a conversion circuit (VCC) 228 is connected between the inputs of the cell switches 218 to 2210 and the main highway 204. A conversion circuit (VCC) 229 is connected between the inputs of the cell switches 222 to 224 and the input highway 205. Cell switch 210.214.218
．． The output of cell switch 222 is connected to output highway 206, the output of cell switch 211.215.219.223 is connected to output highway 207, and the output of cell switch 212.216.220.224 is connected to output highway 208. connected and cell switch 213.21
? , 221.225 are connected to outbound highway 209.

According to an embodiment of the present invention, three of the four incoming highways
Return circuits 230, 231, and 232 are connected to the main highways 202, 203, and 204, respectively, and a test cell generation circuit (G) 233 is connected to the remaining human highway 205. Folding circuit 230
-232 have a function of receiving cells (1), (2), and (2) output from output highways 206-208, respectively, and returning them to conversion circuits (VCC) 226-228.

One output highway 209 is connected to the test cell receiving circuit 234.
It is connected to the.

In this embodiment, it is assumed that the cell identification code VCI output from the test cell generation circuit (G) 234 is '5''.

FIG. 3 is a circuit diagram showing one configuration of folding circuits 230-232. As shown in the figure, the return circuit includes a waiting buffer 331 for storing cells from the communication path, and a cell identification code VC in the signal cell from the corresponding outgoing highway.
It consists of a determination circuit 332 that determines I, and a selection circuit 333 that selects and outputs the test cell instead of outputting it from the waiting buffer 331 when the determination circuit 332 determines VCI '5'' of the test cell.

Figure 4 shows conversion circuits (VCC) 226 to 229 +, :-
A conversion table from Okel VCI to TAG is shown. As shown in the figure, when the VCI of the test cell, 5'', is input, in this embodiment, VCC 226 uses this as the TA.
Convert to G "1'", VCC227TEH, :ReoTA
G ``3'' i: Converts, VCC 228 te It ,: Converts it to TAG ``4'' l: Converts this to TAG ``2''.

The operation of the continuity test using the circuit shown in FIG. 2 will be explained below with reference to FIGS. 5 to 7. In addition, in the following explanation, major highways 202 to 205 will be represented by 1.2.3.4, respectively.
Exit highways 206 to 209 are also 1.2.3 respectively.
Represented by 4.

(1) Confirming the normality of the communication path For example, as shown in FIG. 5, consider the case where a test is performed on the path 2-3 between the incoming highway 2 and the outgoing highway 3. In this embodiment, the test cell generation circuit (G) 233 is connected to the incoming highway 4, and the test cell receiving circuit 234 is connected to the outgoing highway 4, so in order to test path 2-3, , paths 4-2 and 2-3.3-4 may be set. For this purpose, it is sufficient to define the contents of the table of the conversion circuit as shown in FIG.

The VCI in the test cell output from the test cell generation circuit (G) 233 is ``5'', and VCC2
In No. 29, the TAG corresponding to VCI P5'' is "2" as seen from the table in FIG.

When this signal is input to the loopback circuit 231 connected to the corresponding input highway 2, it is looped back and input to the VCC 227 via the input highway 2. VCC
227, 11511 of vCI from the table in FIG.
is converted to TAG “3”, and therefore, the test cell is input from the incoming highway 2 and outputted to the outgoing highway 3 along the non-test path.

The test cell from the outbound highway 3 is looped back by a loopback circuit 232 connected to the corresponding inbound highway 3,
It is input to VCC 228 via input highway 3. V
For CC228, from the table in Figure 4, VCI 5''
is converted to TAG “4”, and therefore, the test cell is input from the input highway 3, outputted to the output highway 4, and received by the test cell receiving circuit (C) 234. In the test cell receiving circuit (C) 234, the test cell is correct;
If the data can be received without any omissions, the continuity test is complete. However, ^
Since it is a TM exchange, there is a probability that cells will be discarded, but if the cell discard is within the allowable range, it is determined to be normal. The dotted lines in FIGS. 2 and 6 indicate the path through which the test cell described above passes.

If an abnormality is detected during this test, it is necessary to identify its location. For this purpose, it is assumed that there is no double failure within the communication path. In other words, it is assumed that abnormal failures do not occur simultaneously at two or more cross points.

Then, as shown in FIG. 7(a), paths 4-2 and 2-4
Then, as shown in Figure 7, pass 4-
3 and 3-4 may be used to conduct the continuity test. If no fault is detected in this continuity test, it is understood that there is a fault in path 2-3, which was the object of the first continuity test shown in FIG.

Normally, the purpose of this processing is to confirm the normality of the device, and the frequency of transmitting test cells is kept low to the extent that it does not interfere with cell exchange operations from communication paths other than test cells, and all paths are periodically tested.

(2) Bandwidth Guarantee According to another embodiment of the present invention, the test cell generation circuit (G) 2
33 has an additional function of controlling the frequency of cell occurrence. Then, at the time of call setup, the test cell generation circuit (G) 2
33, test cells are passed through a path similar to the continuity test described above at a frequency corresponding to the band allocation for the call. At this time, if the quality required by the test cell receiving circuit (C) 234 is satisfied, a pass is set.

〔Effect of the invention〕

As explained above, according to the present invention, means is provided for wiping the output test cell from the outbound highway onto the paired major highway and returning it to the ATM switching communication path, and the test cell connected to the specific person highway is provided. By passing the return circuit between the generation circuit and the receiving device of the test equipment connected to a specific output highway, all possible combinations of paths between the input and output highways can be set, and the test signal can be transmitted there. The normal operation of the communication path can be confirmed through the cell.

Since the test cell generation circuit only needs to be connected to a single input highway, and the receiving circuit to be tested only needs to be connected to a single output highway, the amount of hardware is significantly reduced compared to the conventional method.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the principle of the present invention. FIG. 2 is a block diagram showing the configuration of an ATM switching channel according to an embodiment of the present invention. FIG. 3 is a block diagram showing the configuration of one of the loopback circuits shown in FIG. 2. 4 is a diagram showing the contents of the conversion table in the conversion circuit (VCC) shown in FIG. 2, FIG. 5 is a diagram illustrating the path under test according to the embodiment of the present invention, and FIG. FIG. 7 is a diagram illustrating a continuity test of a path under test according to an embodiment of the present invention; FIG. 7 is a diagram illustrating fault point identification according to an embodiment of the present invention; FIG. 8 is a block diagram showing a conventional configuration. In the figure, 1 is an incoming highway, 2 is an outgoing highway, 3 is an ATM communication path, 4 is a test cell generating means, 5 is a test cell receiving means, 6 is a return means, and 7 is a path setting means.

Claims (1)

[Claims] 1. A plurality of ingress highways (1) and a plurality of egress highways (
2), a test cell generating means (4) connected to one of the input highways (1) and generating test cells containing a test VCI; A test cell receiving means (5) which is connected to one of the highways (2) and receives the test cell, and a test cell receiving means (5) that receives the test cell from the outgoing highway on the incoming highway paired with each of the outgoing highways (2). a test cell loopback means (6) for looping back only a test cell; and a test path setting means (7) for forming a communication path for the test cell within the ATM communication path (3); The test cell generated in step (4) is looped back by the test cell loopback means (6), guided to the route to be tested within the ATM communication path (3), and the test cell generated in the test cell receiver (5) is A continuity test method for an ATM switching channel, characterized in that continuity of the test target route in the ATM channel (3) is confirmed by detecting a test VCI. 2. In the continuity test method according to claim 1, the test cell generating means (5) includes means for controlling the frequency of generation of test cells, and generates cells corresponding to the bandwidth allocation request of the path and A line setting method that connects a call after confirming that the service quality is satisfied.