Converting Apparatus for converting internet protocol address and Home network system using thereof

An internet protocol address converting apparatus (100) has an address acquiring unit (120) for acquiring a first private IP address in a first IP address format by connecting to a DHCP server (35,55) that dynamically allots the IP address, and also acquiring a second private IP address for the second terminal; a network address providing unit (130) for allotting the second terminal with a network address to generate a global IP address; a storing unit (140) for storing a mapping table, the mapping table saving the second private IP address of the second terminal and the global IP address; an address converting unit (150) for converting the second private IP address into the global IP address; and a control unit (110) for performing an announcing, requesting a registration of the second terminal to a master server.