KR19980077124A - Periodic Path Test Method between Matching Modules in a Single Subscriber Switching Subsystem in Asynchronous Transfer Mode Switching Systems - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

Periodic path test method between matching modules in a single subscriber switching subsystem.

2. The technical problem to be solved by the invention

During the operation of the ATM switching system, the operator specifies the monitoring cycle and periodically tests the paths formed between all matching modules in the single subscriber switching subsystem and notifies the operator of the test results.

3. Summary of Solution to Invention

Bandwidth is allocated to each port connecting two matching modules to be tested, each routing module controller is informed of routing tag information to change the received test cell, and the test information is sent to the test device to start the test. After receiving the result, it records in the database and performs the test through the same method for the next test object. When the test for all matching modules is completed, the path test result is output to the operator.

4. Important uses of the invention

Path test of ATM switching system—used in the method.

Description

Periodic Path Test Method between Matching Modules in a Single Subscriber Switching Subsystem in Asynchronous Transfer Mode Switching Systems

The present invention relates to a periodic path test method between an interface module (IM) in a single ATM local switching subsystem (ALS) in an Asynchronous Transfer Mode (ATM) switching system.

The ASW (Access Switch), a switch in the ASS of the Asynchronous Switching Mode (ATM) switching system, consists of 32X32 input / output ports, each of which is connected to a call connection control processor (CCCP) or a subscriber / relay line. It is connected to the matching module and to the central switch (CSW) of the central switching subsystem (ACS).

In the asynchronous delivery mode (ATM) switching system, the end-user call service occurs between two matching modules (IM). There is a need for a way to test connectivity and performance between IMs. In addition, for maintenance purposes, it is necessary to check this periodically to prevent it before a failure occurs or to recover the location of the failure.

Existing asynchronous delivery mode (ATM) switching system does not have a test method to check the connection status between two matching modules (IM) in a single subscriber switching subsystem (ALS) periodically during system operation. There is a need for a method for performing periodic path tests that does not affect user call services.

Accordingly, the present invention provides the operator with a monitoring cycle during the operation of the ATM switching system to periodically test the path formed between all matching modules IM in the single subscriber switching subsystem (ALS) and notify the operator of the test results. In addition, the operator can know the path status between all matching modules (IM) periodically, and if a failure occurs, the purpose is to provide a path test method that can know the location information of the failure.

1 is a schematic configuration diagram of an asynchronous transfer mode (ATM) exchange system to which the present invention is applied;

2 is an explanatory diagram of an inter-block operation for performing a path test;

3 is a diagram illustrating a path connecting two matching modules in a subscriber switching subsystem (ALS);

4 is a table illustrating routing tag information for a path test between two matching modules in a subscriber switching subsystem (ALS).

5A through 5C are process flow diagrams of a periodic path test method according to the present invention.

* Explanation of symbols for main parts of the drawings

11: ATM Local Switching Subsystem (ALS)

12: ATM Central Switching Subsystem (ACS)

13 Subscriber Interface Module (SIM)

14 Trunk Interface Module (TIM)

15: Access Switching Network Module (ASNM)

16: Call Connection Control Processor (CCCP)

17 test device

18: Interconnection Switch Network Module (ISNM)

19: Operation and Maintenance Processor (OMP)

In order to achieve the above object, the present invention provides a periodic path test method between matching modules in a single subscriber switching sub-system applied to an asynchronous delivery mode switching system, and determines two matching modules for a path test when a path test is performed. After allocating the bandwidth for each, and preparing the control for the loopback in the determined matching module, and after the preparation is complete, the routing header information to be attached to the test cell is extracted and the path test is requested to the test apparatus. Receiving a result from the test apparatus, a second step of releasing preparation for the path test of the two matching modules currently set, and recording the path test results in the database; and the paths of all matching modules connected in one subscriber switching subsystem. When the test for the above is completed through the above process, the third test result is output to the operator. Characterized in that it comprises a step.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention;

1 shows a schematic diagram of an asynchronous transfer mode (ATM) exchange system to which the present invention is applied.

In general, the ATM switching system is largely composed of a plurality of subscriber switching subsystems (ALS) 11 and a central switching subsystem (ACS) 12.

Subscriber Switching Subsystem (ALS) 11 includes an Access Switching Network Module (ASNM) 15, which is a self routing switch module, and is a call connection control processor for user call processing and maintenance. (CCCP) 16, a Subscriber Interface Module (SIM) 13 for registration with subscribers, and a Trunk Interface Module (TIM) 14 for registration with relay lines. do.

A subscriber switching subsystem (ALS) 11 operates as a concentrating device having an aggregation ratio of n: m, where n is the number of user-side links and m is the number of switch-side links, and the central switching subsystem (ACS) 12 Performs the interconnection function between the subscriber switching subsystem (ALS) 11 to operate as a distribution device for a large capacity system.

When a call request is made from a subscriber, the subscriber switching subsystem (ALS) 11 detects it, performs a call service, and calls the corresponding subscriber switching subsystem through the called subscriber number under the control of the originating subscriber switching subsystem (ALS). ALS) and request translation of the number to the called subscriber exchange subsystem (ALS).

The terminating subscriber exchange subsystem (ALS) selects an optimal path at the same time as number translation and notifies the originating subscriber exchange subsystem (ALS), and the originating subscriber exchange subsystem (ALS) establishes a call path.

The originating subscriber exchange subsystem (ALS) counts the cells delivered during the call, sends the billing data to the central switching subsystem (ACS) along with the user requested service after the call completes, and the originating subscriber exchange subsystem (ALS). Restores the call data to a dormant state.

The central switching subsystem (ACS) 12 is a pure interconnector without call processing that exchanges information between the subscriber switching subsystems (ALS), unlike the subscriber switching subsystem (ALS), the call connection control processor. Do not put (CCCP).

An Interconnection Switch Network Module (ISNM) 18, which is a switch network module of the central switching subsystem (ACS), uses the same switch element as a subscriber switching subsystem (ALS) as a magnetic routing switch. Can be. In addition, the Central Exchange Subsystem (ACS) has an Operation and Maintenance Processor (OMP) (19) for system-wide operation and maintenance, as well as system-wide maintenance, testing, measurement, and statistical functions. Mass storage device control management and various input / output statement control with the operator.

Here, the test apparatus 17 exists for each subscriber switching subsystem (ALS) and performs a test function.

2 is an explanatory diagram of inter-block connections for performing a periodic path test according to the present invention.

The path test block 21 is located in the call connection control processor (CCCP) and performs a series of tasks to prepare for the path test. That is, the path test block 21 requests the call processing block 22 for the bandwidth allocation required for the path test for the two matching modules IM in the single subscriber switching subsystem ALS that is the path test target when the periodic path test time comes. When the band is allocated, the routing module information is notified to the matching module (IM / subscriber / relay line) control unit 23, and when the response is received from the matching module control unit 23, the test information is sent to the test device 17. Require a test start. The test information sent to the test device consists of routing tag information attached to the test cell, the number of test cells, the test run time, and the traffic generation mode.

When the test result is transmitted from the test device 17, the path test block 21 stores the test result in the database until the path test for all matching modules IM is completed, and then all the matching modules IM When the path test for) is completed, the result is output to the operator.

The call processing block 22 manages currently available bands, and performs a function of allocating / releasing a band required for a path test.

The matching module control unit 23 performs a function of loopbacking the test cell coming into the matching module IM according to the routing tag information transmitted from the path test block 21.

The test apparatus 17 generates a test cell including the routing tag information input from the path test block 21 and transmits the cell along the corresponding path. When the transmitted cell is received through the path, the test cell 17 transmits the received cell. By comparing with the cells, the number of lost cells, the number of error cells, the number of duplicate cells, the average cell transmission delay, and the like are measured, and the result is notified to the path test block 21.

When the path test is completed, the path test block 21 returns the band to the call processing block 22 and notifies the matching module controller 23 of the end of the loop back.

3 is a diagram illustrating a connection path between two matching modules IM in a subscriber switching subsystem (ALS).

The path test block in the call connection control processor (CCCP) is a call processing block that bidirectionally transfers the bandwidth required for the path test for each random I-th matching module (IM # I) and random J-th matching module (IM # J). To be allocated.

When a band is allocated for a port connecting any two matching modules (IM), the matching module (IM) control routes to each of the matching modules IM # I and IM # J to receive and loop back the test cell. Notify the tag information and the virtual path identifier (VPI) / virtual channel identifier (VCI) information of the test cell. If this process is successful, the path test block in the call connection control processor (CCCP) requires test cell generation to the test device (31).

The test apparatus generates a test cell (32) and transmits it to an arbitrary matching module IM # I (33), which matches the routing tag information of the test cell so that the path test cell is transmitted to the matching module IM # J. Change it and transmit it to the matching module IM # J (34). The matching module IM # J changes the routing tag information of the test cell so that the received test cell can be transmitted to the test apparatus and transmits the routing tag information to the test apparatus (35).

The test apparatus analyzes the test cell looped back from the matching module IM # J and notifies the test result to the path test block in the call connection control processor (CCCP) (36). When the path test is completed, the path test block in the call connection control processor (CCCP) returns a band to the call processing block and notifies the IM # I control unit and the IM # J control unit of the loopback termination.

Thereafter, the same test is performed on the next test object, and each test result is recorded in the database as shown in [Table 2], and after the test for all matching modules is finished, the test result is output to the operator.

4 shows routing tag information pasted from a test device, IM # I, IM # J, to perform a path test connecting two matching modules IM in the same subscriber switching subsystem (ALS).

The test apparatus assigns the port number to which the IM # I is connected to the first byte of the routing tag in order for the test cell to be sent to IM # I (41). IM # I assigns the port number to which the IM # J is connected to the first byte of the routing tag so that the test cell received from the test apparatus is sent to IM # J (44). IM # J assigns the port number to which the test device is connected to the first byte so that the test cell received from IM # I returns to the test device (47).

Table 1 shows the path test contents required by the path test block to the test apparatus. The path test requirement consists of routing tag information, test run time, path test bandwidth, and traffic mode (1 cell / even cell / burst cell).

Table 2 shows the path test results to be stored in the database.

ASW number, port number to which IM # I is connected, port number to which IM # J is connected, path test run time, path test bandwidth, traffic mode, number of test cells generated, number of received cells, number of error cells, number of lost cells, duplicate Number of cells, and cell transmission delay time.

The number of test cells generated is the number of test cells generated for the test. The number of cells in which an error occurs is measured by a header error control (HEC) test and a cyclic redundancy check (CRC). If the number of lost cells is discontinuous in the cell number among correctly received cells without error, cell loss is generated by the number of discontinuous cells. The number of duplicated cells is determined to be a duplicated cell if the cell number has the same value among cells correctly received without error. The average cell transmission delay measures cell transmission delay time and cell reception time in microseconds.

TABLE 1

Path test requirements

TABLE 2

Path test results

5A-5C show a flow chart of a periodic path test method according to the present invention.

When it is time to perform the path test (101), the random value I representing the originating port to be tested is initialized to 0 (102), and it is checked whether the set port I is a user port connected to the matching module (IM) (103). .

If the set port I is not connected to the matching module (IM), increase the value of I by 1 (121), and increase if the value of the increased I is not greater than the maximum port-1 value representing the end of the test object (122). Repeat the procedure below to determine if port I is the user port.

If the configured port I is a user port connected to the matching module (IM) (103), an arbitrary J value representing the destination port to be tested is set to a value of I + 1 (104), and the set arbitrary port J matches. Check whether the user port is connected to the module IM (105).

If any port J is not a user port connected to the matching module (IM), increase the value of J by 1 (116), and increase it if the increased value of J is not greater than the maximum port value representing the end of the test object (117). Investigate if port J is your port.

If the set port J is a user port connected to the matching module IM (105), path test preparation for the configured matching module IM # I is performed (106).

Looking at the path test preparation process with reference to Figure 5B, first if the bandwidth required for the path test for the port connecting the IM # I from the call processing block in both directions (201), and notifies the preparation incomplete (206), The failure to perform the path test is recorded in the database with the cause (118).

When the bandwidth is allocated (201), the control unit address of IM # I is calculated (202), and the information to be appended to the routing header to loop back the test cell IM # I received from the test apparatus to IM # J is extracted (203). In step 204, it transmits to the IM # I control unit.

When the IM # I control unit is ready to loop back the test cell (205), it notifies the preparation completion (207), and if the preparation is not complete (205), it notifies the preparation incomplete (206).

Once the IM # I is ready (107), the path test preparation for IM # J performs the path test preparation for IM # J through the same process (FIG. 5B) as the path test preparation for IM # I (108). .

That is, if the bandwidth required for the path test is allocated to the port connecting IM # J from the call processing block in both directions (201), the address of the IM # J controller is calculated (202), and the IM # J is received from IM # I. In order to loop back a test cell to the test apparatus, information to be attached to the routing header is extracted (203) and transmitted to the IM # J control unit (204). If the IM # J control unit is ready to loop back the test cell (205), it notifies the preparation completion (207), and if the preparation is not complete (205), it notifies the preparation incomplete (206).

If no bandwidth is allocated for the port connecting IM # J (201), the preparation is notified of completion (206).

If the IM # J is not ready for the path test (109), it releases the IM # I path test preparation (119) and records in the database that the path test cannot be performed (120).

If both IM # I and IM # J are ready (109), the routing device extracts routing header information to be attached to the test cell (110) and requests the test device to start the path test (111).

When the test is completed and the test result is notified from the test device (112), the IM # I and IM # J path test preparations are released (113,114), and the path test result is recorded in the database (115).

The path test preparation release for IM # I and IM # J (FIG. 5C) returns the allocated bandwidth (301), calculates the addresses of the IM # I control unit and the IM # J control unit (302) and the IM # I control unit. This is accomplished by notifying the IM # J control unit of the end of the path test (303).

After recording the test result about the currently set path in the database, increase the value of J indicating the port of the called party by 1 (116) and increase the port J if the value of the increased J is not greater than the maximum port value (117). Repeat step 105 of checking whether the port is a user port, and if the value of the increased J is greater than the maximum port value and there are no more ports to select with IM # J, the value of I is increased by one (121). If the value of I is not greater than the maximum port-1 value (122), repeat the process of checking if the increased port I is the user port (103) or less, and if the value of the increased I is greater than the maximum port-1 value, then all Since the path test for the matching module (IM) is completed, the path test results recorded in the database are output to the operator (123), and the path test for the matching module is terminated.

The present invention described above is capable of various substitutions, modifications, and changes within the scope without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains, and thus is limited to the above-described embodiments and drawings. It is not.

According to the present invention as described above, by periodically testing a connection path between two IMs in a single ALS, a failure state can be detected and prevented in advance, thereby increasing the availability of the internal path of the switch, the stability of the path, and the reliability of the call processing. As in the case of processing a general user call from a block, the path test is performed with bandwidth allocation, and thus, the path test can be performed without affecting the call processing service currently in progress.

Claims (6)

In the periodic path test method between matching modules in a single subscriber switching subsystem applied to an asynchronous delivery mode switching system, A first step of determining two matching modules for a path test by allocating a bandwidth for each path test and preparing a control for loopback in the determined matching module when a path test execution time arrives; After the preparation is completed, the routing header information to be attached to the test cell is extracted, and after the path test is requested to the test apparatus, when the result is received from the test apparatus, the path test result of the two matching modules currently set is canceled, and the path test result Recording the data into a database; And When the test of the paths of all matching modules connected in one subscriber switching subsystem is completed through the above process, the matching modules in the single subscriber switching subsystem including the third step of outputting the test results to the operator Periodic path test method. The method of claim 1, The first step is, A fourth step of setting any port I, J to any initial value so that the path test for all user ports connected to the matching module existing in the single subscriber switching subsystem when the path test execution time comes can be performed; If the bidirectional bandwidth allocation for the arbitrary port I set in step 4 is possible, the address of the matching module controller connected to the port I is calculated, and the routing module information to be attached to the test cell is extracted from the matching module. A fifth step of transmitting routing header information to the matching module controller; If the bidirectional bandwidth allocation for the arbitrary port I is not possible or if the matching module controller is not prepared, the path test is not performed in the database, and the value of the random port J is increased by 1 to the maximum port. A sixth step of repeating the steps; A seventh step of performing a path test preparation for the arbitrary port J through the same process as the fifth step when the preparation for the path test for the arbitrary port I is completed; And After performing the seventh step, if the bidirectional bandwidth allocation for any port J is not possible or the matching module controller is not ready, the path test preparation for the random port I is canceled, and the path test cannot be performed in the database. Thereafter, the eighth step of repeating the fourth step to the maximum port by increasing the value of any port J by 1, the periodic path test method between the matching modules in a single subscriber switching subsystem. The method of claim 2, The initial value of the arbitrary port I, J in the fourth step is set to any port I is set to a value of 0, and the arbitrary port J is set to a value greater than 1 to the value of the arbitrary port I. A periodic path test method between matching modules in a single subscriber switching subsystem. The method according to claim 1 or 2, Path test preparation release of the arbitrary port, And returning the assigned port bandwidth, calculating an address of the matching module controller, and notifying the matching module controller of the completion of the path test. The method of claim 1, When the path test request to the test device of the second step is transmitted, A periodic path test method between matching modules in a single subscriber switching subsystem including routing tag information to be attached to a test cell, a path test progress time, a path test bandwidth, and a traffic mode. The method of claim 1, Path test result data stored in the database, Port number, path test progress time, path test bandwidth, traffic mode, number of test cells, number of received cells, number of error cells, number of lost cells, and duplicated cells A method for testing periodic paths between matching modules in a single subscriber switching subsystem comprising a number and a cell transmission delay time.