CALL ALARM DEVICE, CALL ALARM SYSTEM, CALL ALARM METHOD, AND CALL ALARM PROGRAM

摘要

The present invention is characterized in that, upon receiving a call signal for which a receiving-side terminal (31) is the transmission destination, an SIP server (24): reads, from the call signal, a number conversion history set by an SIP server (22) that has transferred the call signal by means of a transfer service involving number conversion; and transmits, in the case in which said number conversion history satisfies a specific condition, an alarm signal to the receiving-side terminal (31) before transmitting the call signal to the receiving-side terminal (31). The present invention is also characterized in that the SIP server (24) transmits an alarm signal to the receiving-side terminal (31) in the case in which the specific condition is defined as the number of times the number conversion is performed is equal to or greater than a prescribed number.