SYSTEM FOR INVESTIGATING ADDRESS IN CHANGE DESTINATION OF TELEPHONE NUMBER

摘要

PROBLEM TO BE SOLVED: To provide a system for investigating the address of change destination of a telephone number by which the address in the change destination of the telephone number in efficiently investigated. SOLUTION: This system includes stages (4 and 12), where investigation of usagee conditions of plural telephone numbers connected to ISDN is performed, stages (7 and 14) where collected data of each telephone number is stored as history information, and stages (1 and 9), where the use condition of each telephone number is collected periodically or any time and is stored as history information at each time of use condition investigation and the customer name, of which the changed telephone number is unknown, is retrieved from history information, when the changed telephone number has been unknown for a prescribed time until the present time in usage condition investigation.