Patent ID: 7675907

Claim:
An IP (Internet Protocol) telephone system comprising: an IP telephone apparatus that is connected to an IP network and functions as a base station for a multi-handset telephone system; a Web server that stores ring tone information corresponding to a telephone number assigned to said IP telephone apparatus, and transmits, to said IP telephone apparatus, the ring tone information in response to a request from said IP telephone apparatus; and an ENUM (Telephone Number Mapping) server that stores a NAPTR (Naming Authority Pointer) resource record in which a URI (Uniform Resource Identifier) specifies link data related to the ring tone information, the ring tone information being stored in said Web server, and transmits, to said IP telephone apparatus, the NAPTR resource record in response to a query from said IP telephone apparatus, said IP telephone apparatus, when a call is received, that transmits, to said ENUM server, a query for a NAPTR resource record according to an intended recipient telephone number, transmits, to said Web server, a request for the ring tone information corresponding to the intended recipient telephone number, according to the obtained NAPTR resource record, and sounds a ring tone through the apparatus itself and all handsets that are connected to the apparatus according to the obtained ring tone information.