TELEPHONE NUMBER SURVEY DEVICE, METHOD AND PROGRAM, TELEPHONE NUMBER INFORMATION PROVIDING SYSTEM, AND RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To conduct a survey on whether an IP phone is used or not without ringing nor charging.SOLUTION: A telephone number survey device 10 connected with a SIP server in a communication common carrier connected with an IP telephone comprises: a message exchange control unit 12 that transmits a SIP option request to inquire an option function and capability to a survey object IP telephone 70 or a SIP server 40, and receives a response message via the SIP server 40; and a determination unit 13 that determines whether the survey object telephone 70 is used or not now referring to the response message.SELECTED DRAWING: Figure 3