IP telephone system, IP telephone apparatus and communications method

An IP telephone apparatus connected to a calling IP telephone apparatus via the Internet, the IP telephone apparatus comprising:

• a panel configured to indicate that a user of the calling IP telephone apparatus is available;
• a controller configured to notify the user of the IP telephone apparatus that the user of the calling IP telephone apparatus is available, via the panel, when a notice is received from the calling IP telephone apparatus, the notice indicating that the user of the calling IP telephone apparatus is available.

An ENUM server connected to an IP telephone apparatus, the ENUM server comprising:

• a memory configured to store at least one NAPTR (Naming Authority Pointer) resource record, the NAPTR resource record including a domain name corresponding to a URI;
• and
• a controller configured to receive, from the IP telephone apparatus, a request for registering a NAPTR resource record of the IP telephone apparatus, and to store the received NAPTR resource record of the IP telephone apparatus in the memory to response to the request.

A method for registering a NAPTR (Naming Authority Pointer) resource record of an IP telephone apparatus in an EMUM server, the NAPTR including a domain name corresponding to a URI, the domain name and the URI being associated with the IP telephone apparatus, the IP telephone apparatus being connected to the ENUM server via a network, the method comprising:

• storing, at the IP telephone apparatus, the NAPTR resource record of the IP telephone apparatus;
• and
• transmitting, to the ENUM server, a request for a registering, in the ENUM server, the NAPTR resource record stored in the IP telephone apparatus, whereby the ENUM server can register the NAPTR resource record of the IP telephone apparatus in response to the request.