A method for communication using an ENUM (Telephone Number Mapping) client apparatus and an ENUM server, the ENUM client apparatus being connected to a Web server and to the ENUM server, the Web server storing a plurality of first NAPTR (Naming Authority Pointer) resource records corresponding to an ENUM domain name, each of the first NAPTR resource records including a second URI (Uniform Resource Identifier) associated with a service available to a destination ENUM client apparatus, the ENUM server storing a second NAPTR resource record corresponding to the ENUM domain name, the second NAPTR resource record including a first URI specifying link information to the plurality of first NAPTR resource records stored in the Web Server, and a protocol corresponding to the first URI, the method comprising:
- inputting, at the ENUM client apparatus, a telephone number of the destination ENUM client apparatus;
- generating, at the ENUM client apparatus, an ENUM domain name based on the input telephone number;
- transmitting, from the ENUM client apparatus to the ENUM server, the generated ENUM domain name and a request for transmitting, to the ENUM client apparatus, the second NAPTR resource record corresponding to the generated ENUM domain name;
- receiving, at the ENUM server, the ENUM domain name and the request transmitted by the ENUM client apparatus;
- determining, at the ENUM server, whether the protocol included in the second NAPTR resource record corresponding to the ENUM domain name received from the ENUM client apparatus is a predetermined protocol, the predetermined protocol being operable to encrypt data for transmission,
- transmitting, from the ENUM server to the ENUM client apparatus, the second NAPTR resource record corresponding to the received ENUM domain name, when it is determined that the protocol included in the second NAPTR resource record is the predetermined protocol,
- receiving, at the ENUM client apparatus, from the ENUM server, the second NAPTR resource record corresponding to the generated ENUM domain name;
- transmitting, from the ENUM server to the ENUM client apparatus, an error indication, when it is determined that the protocol included in the second NAPTR resource record is not the predetermined protocol;
- receiving, at the ENUM client apparatus, from the ENUM server, the error indication,
- transmitting, from the ENUM client apparatus to the Web server, a request to access the plurality of first NAPTR resource records, using the first URI included in the received second NAPTR resource record, without using the generated ENUM domain name;
- receiving, at the ENUM client apparatus from the Web server, the plurality of first NAPTR resource records addressed by the link information specified by the first URI;
- and
- accessing, by the ENUM client apparatus, the destination ENUM client apparatus via the Internet, based on the second URI included in one of the received plurality of first NAPTR resource records,
- wherein when the ENUM client apparatus receives, from the ENUM server, the second NAPTR resource record including the predetermined protocol, the ENUM client apparatus transmits, to the Web server, the request to access the plurality of first NAPTR resource records, utilizing the predetermined protocol, and receives, from the Web server, the encrypted plurality of first NAPTR resource records, utilizing the predetermined protocol, and
- wherein for every domain name transmitted to the ENUM server, the second URI to access the destination ENUM client apparatus is obtained by reference to the Web server based upon the link information specified by the first URI corresponding to the transmitted domain name in the ENUM server.