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On Line Test Operations in a Switching System

IP.com Disclosure Number: IPCOM000088653D
Original Publication Date: 1977-Jul-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 4 page(s) / 55K

Publishing Venue

IBM

Related People

Mariotti, R: AUTHOR

Abstract

On-line tests are performed in a switching system to check the validity of the information contained in the main tables of the operational program so that software errors are detected as soon as they occur and that the events that caused them are immediately identified.

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On Line Test Operations in a Switching System

On-line tests are performed in a switching system to check the validity of the information contained in the main tables of the operational program so that software errors are detected as soon as they occur and that the events that caused them are immediately identified.

As shown in Fig. 1, the switching system comprises two switching networks S1 and S2. S1, the main network, connects any two input lines Lm and Lp through a junctor Jij and two feeders Fi and Fj. It comprises four stages (1, 2, 3 and 4) of switching matrices.v Once the two input lines to be connected are known and the junctor is selected, the input of stage 1 (line address SRQP) and the output of stage 4 (feeder address DCBA) determine the connecting path within switching network S1.

S2 is the service network. It connects feeder Fi to service devices S, such as tone senders, tone detectors, multifrequency receivers and operators. It comprises three stages (5, 6 and 7) of switching matrices which connect the input of stage 5 (feeder address DCRA) to the output of stage 7.

The input lines and the junctors have an image in tables stored in the system memory and called line tables (TXT's) and feeder tables (TRA's) (Fig. 2).

Since the physical line addresses (SRQP's) and feeder addresses (DCBA's) are not sequential, new sequential parameters (XTDP's and TBA's) corresponding to these addresses have been created to address the line and feeder tables.

Two fields are allocated to each 16-bit line table entry as follows: - a 10-bit field (0-9) indicating either . a Stand-Alone-Status of the line if the line is not involved

in a transaction, or

. the software address (TBAY of the associated feeder if the

line is involved in a transaction, and - a 6-bit field (A-F) indicating the class of services (CS) of the line, i.e., the feature the line can access. 16-bit feeder table entry comprises: - a 12-bit field (0-B) indicating the address (XTDP) of the line associated with the feeder (if any), and - a 4-bit field (C-F) indicating the side status (SS) of the transaction i.e., a value depending on the status of the path formed by

the line, the feeder and the service device (if any).

In this table, entries are arranged in such a way that the two feeders Fi and Fj, attached to a junctor Jij, are assigned consecutive positions.

Status changes are controlled by the switching system which handles the telephone events by establishing the physical connections between the lines, the

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feeders and the service devices and which updates the software images of the hardware elements contained in the tables.

On-line tests check the table contents and send error messages when anomalies are detected.

Routines or traps check the adequacy and/or the compatibiiity of the information contained in the tables.

For example, the configuration represented in Fig. 1 is checked in:

. verifying the chaining of Line Table TXT and Feeder Table TRA,

as show...