PURPOSE: To allow the system to make detailed operation with high reliability by bypassing calls requiring processing relating to a faulty service without bypassing all of calls.

CONSTITUTION: Service relevant process means 31-3m make processing specific to service in a message distributed from a message handler 2 and give the message to call processing process means 41-4n, from which converted number information and processing information are returned. The service relevant process means 3 informs function stop information to a telephone exchange 5 through a message handler 2 when a fault of database specific to the service is detected. A telephone exchange 5 bypasses a call requiring processing relating to the service whose function is stopped to other service control processor 1.