In load sharing mode, the prevention of duplicate calls and fault control method for shared DB SCPs

摘要

PURPOSE: An overlapped call prevention and fault processing method is provided to make systems share database divided by a reference for preventing overlapped calls, and make other systems recognize a fault generated in one system and automatically share the database allocated in the fault system for preventing a loss of calls. CONSTITUTION: The method comprises steps of starting a call generation service in an idle state(S1, S2), a service logic program reading point codes and sub-system number of a service control system, comparing the read data with data registered in a table 1, and recognizing a range of database of call arrival numbers to be processed(S3), the service logic program sending messages to a backup system with the point code and the sub-system number of the backup service control system registered in the table 1(S4), the service logic program adjusting a range of the database to be searched according to the state of the backup service control system(S5), allocating signals of a corresponding event for checking state change of the backup service control system(S6), allocating a timer to determine a database search frequency(S7), getting in a signal waiting state(S8), determining the state change of the backup service control system if a signal of the state change is sensed, setting the database search range to a self system and a backup system if the state of the backup service system is converted from a normal to an abnormal state, setting the database search range to the self system if the state of the backup service system is converted from an abnormal to a normal state, generating a message for reflecting the state of the self system on the backup system, allocating a state change signal again and allocating a database search timer.