EXCHANGE AND ITS CONTROL METHOD

摘要

An exchange capable of adequately suppressing calls seeming single-ring-and-hang-up solicitation calls. The exchange (300) measures the time from calling (or start of ring-back tone sending) till the disconnection. If the time is shorter than a predetermined time, the call is judged as a single-ring-and-hang-up solicitation call and stored in a database server (102). When a call back for the call judged as a single-ring-and-hang-up solicitation call is made, the exchange (300) changes the charging method to charge the caller who has made the single-ring-and-hang-up solicitation call for the call back between terminals according to the data stored in the database server (102).