Patent ID: 7729341

Claim:
An Internet Protocol (IP) telephone apparatus connected to a Telephone Number Mapping (ENUM) server and a Domain Name System (DNS) server via a network, the ENUM server storing a Naming Authority Pointer (NAPTR) resource record of the IP telephone apparatus, the NAPTR resource record including a domain name corresponding to a Uniform Resource Identifier (URI), the domain name and the URI being associated with the IP telephone apparatus, the DNS server storing an IP address corresponding to the URI, the IP telephone apparatus comprising: a memory that stores the NAPTR resource record of the IP telephone apparatus, and that stores a plurality of telephone numbers, wherein each telephone number is associated with a different predetermined call destination to transmit a notice indicating that a user of the IP telephone apparatus is available; a panel that includes: a first predetermined key, when actuated by the user of the IP telephone apparatus, that causes the IP telephone apparatus to initiate an automatic notification of each of the different predetermined call destinations that the user is available to answer the IP telephone apparatus; a second predetermined key, when actuated by the user of the IP telephone apparatus, that causes the IP telephone apparatus to initiate an automatic notification of each of the different predetermined call destinations that the user is not available to answer the IP telephone apparatus, and a controller that: transmits, to the ENUM server, a request for registering, in the ENUM server, the NAPTR resource record stored in the memory of the IP telephone apparatus when the predetermined key of the panel is selected, whereby the ENUM server stores the NAPTR resource record of the IP telephone apparatus in response to the request, obtains, from the ENUM server, a NAPTR resource record of each predetermined call destination, based on the plurality of telephone numbers stored in the memory of the IP telephone apparatus when the first predetermined key of the panel is selected, obtains, from the DNS server, an IP address of each predetermined call destination, based on the URI included in the NAPTR resource record of each predetermined call destination obtained from the ENUM server, and transmits, to each predetermined call destination, a notice indicating that the user of the IP telephone apparatus is available, based on the IP address of each predetermined call destination obtained from the DNS server.