IP telephone system, IP telephone apparatus and method for identifying destination user

An Internet Protocol (IP) telephone apparatus that receives calls, which is connected to a Web server and a Telephone Number Mapping (ENUM) server, the Web server storing call reception screen information corresponding to each of a plurality of concurrently active telephone numbers assigned to the call receiving IP telephone apparatus on an IP network, the ENUM server storing a plurality of Naming Authority Pointer (NAPTR) resource records for a given ENUM domain name, in which a Uniform Resource Identifier (URI) of each of the plurality of NAPTR resource records specifies link information for the call reception screen information, the call reception screen information being stored on the Web server, the call receiving IP telephone apparatus comprising:

• a receiver for receiving an INVITE message according to Session Initiation Protocol (SIP);
• an extractor for extracting a called intended recipient telephone number from the received INVITE message;
• a generator that generates an ENUM domain name from the called intended recipient telephone number upon reception of a call from a call originating IP telephone apparatus for the intended recipient telephone number of the plurality of concurrently active telephone numbers assigned to the call receiving IP telephone apparatus;
• a querier that transmits, to the ENUM server, a query for a generated ENUM domain name of an NAPTR resource record comprising the URI corresponding to the call reception screen information for the called intended recipient telephone number;
• a requester that transmits, to the Web server, a request for the call reception screen information corresponding to the called intended recipient telephone number, wherein the request includes the URI corresponding to the call reception screen information, the URI being obtained from the queried NAPTR resource record;
• a display that displays a call reception screen with obtained call reception screen information that corresponds to the intended recipient telephone number;
• and
• a speaker for sounding a ring tone.

A method for identifying a destination user using an Internet Protocol (IP) telephone apparatus that receives calls, the call receiving IP telephone apparatus being connected to a Web server and a Telephone Number Mapping (ENUM) server, the Web server storing call reception screen information corresponding to each of a plurality of concurrently active telephone numbers assigned to the call receiving IP telephone apparatus on an IP network, the ENUM server storing a plurality of Naming Authority Pointer (NAPTR) resource records for a given ENUM domain name, in which a Uniform Resource Identifier (URI) of each of the plurality of NAPTR resource records specifies link information for the call reception screen information, the call reception screen information being stored on the Web server, the method comprising:

• receiving, by the call receiving IP telephone apparatus, an INVITE message according to Session Initiation Protocol (SIP);
• sounding a ring tone;
• and
• performing the following at a period from the reception, by the call receiving IP telephone apparatus, of the INVITE message according to SIP protocol to the sounding of the ring tone:
• extracting a called intended recipient telephone number from the received INVITE message;
• generating, by the call receiving IP telephone apparatus, an ENUM domain name from the called intended recipient telephone number upon reception of a call from a call originating IP telephone apparatus for the intended recipient telephone number of the plurality of concurrently active telephone numbers assigned to the call receiving IP telephone apparatus;
• transmitting, by the call receiving IP telephone apparatus to the ENUM server, a query for the generated ENUM domain name of an NAPTR resource record comprising the URI corresponding to the call reception screen information for the called intended recipient telephone number;
• transmitting, by the call receiving IP telephone apparatus to the Web server, a request for the call reception screen information for the called intended recipient telephone number, wherein the request includes the URI corresponding to the call reception screen information, the URI being obtained from the queried NAPTR resource record;
• and
• displaying, by the call receiving IP telephone apparatus, a call reception screen with obtained call reception screen information that corresponds to the intended recipient telephone number.