The “system restart” of the program control switch is an automatic troubleshooting program that is set by itself to exclude certain system failures (mostly software failures). When the program-controlled switchboard is in operation, if it is interfered with internally or externally, it will easily cause "system restart", which will directly affect the communication quality and equipment maintenance.

First, the main cause of "system restart"

First, due to human-induced reactivation. Program-controlled exchanges mainly include low maintenance technicians with low skill levels, unskilled operation, artificially entering dangerous commands or changing office data; inter-office trunk lines that are interrupted due to natural disasters or human factors and transmission equipment failures, causing system confusion after system reconfiguration. Power system failure caused the system to lose power and reload.

The second reason is that due to the irrational network structure, traffic overload caused by restart. The traffic distribution of each cabinet in the main office and the module office is unbalanced and exceeds the processing capacity that the processor can handle; the number of office routes and trunks introduced into the switch is too large and the load is too heavy; the local call terminal office and the long distance access office When connected via a digital trunk, the object of the extracted clock is different. The

The third is the restart caused by problems and defects in the software and hardware of the program control switch itself. Mainly there is no backup of working software. Once it is damaged, it cannot be switched automatically. It has low processing capacity and can not tolerate excessive traffic, resulting in traffic congestion. The software version is low and the function is not perfect, resulting in the inability to automatically disconnect the line after a long distance. Problems such as users, virtual trunk occupation, and virtual link occupation of internal links occur during abnormal connections.

Second, the main countermeasures to prevent or reduce system restart

The first is to strengthen technical training and improve on-duty maintenance capabilities. It is necessary to adopt a flexible and diversified approach to strengthen the technical training of on-duty maintenance personnel and improve the quality of service. When a system failure occurs, it can be handled in a timely and correct manner to prevent “restart” upgrades and prolong the duration of failures. Strict implementation of man-machine commands is required. The management system should be cautious in using dangerous man-machine commands; it must strengthen the maintenance of system software and promptly make up the transcription of backup information.

The second is to adjust the network structure and improve the stability of the equipment. To grasp the traffic distribution situation, timely adjust the network structure, reasonably arrange the installation of LIM rack users, evacuation of system traffic, reduce the total number of busy calls, to avoid causing the connection is not smooth, blocked channels, traffic out of control and so on; To strengthen the management of program-controlled switches and trunk maintenance, to prevent the switch equipment itself and trunk failure and the emergence of a low rate of connection, blocking, traffic is too high; to reduce the introduction of the main office of the number of long-distance and trunk, the maximum To relieve the burden on the main office; to properly resolve the synchronization mode between digital network offices, it is recommended that the long-distance tandem exchange and the local terminal station and each user-controlled exchange connected to the digital circuit adopt the “master-slave” synchronization mode.

The third is to carry out version upgrades in due course, program-controlled exchanges to improve system software capabilities. When the version is upgraded, software debugging is complicated and the replacement of the hardware of the switching system is more difficult, requires higher requirements, involves a wide range, and the entire network is interrupted for a long time. Therefore, prior to the version upgrade, it is necessary to seriously organize technical personnel and relevant experts to conduct repeated argumentation, formulate practical implementation plans and emergency measures, and ensure that the version upgrade is successful at the premise of full preparation.