Private ip address operator in multimedia satellite communication system

PURPOSE: A private Internet protocol(IP) address operator in a multimedia satellite communication system, is provided, that one set top box and personal computers to the set top box execute communication, based on each fixed allocated private IP address, and to supply a multimedia service based on a public IP address allocated from a central station when a subscriber communicates with a multimedia server or a Internet. CONSTITUTION: A private Internet protocol(IP) address operator in a multimedia satellite communication system supplying a communication link between a subscriber and an internet or a multimedia server, comprises a central station(1), a set top box(41-4n), and communication terminals(511-51n, 5M1-5Mn). The central station(1) manages all public IP addresses used in the system, and allocates public addresses to be used presently, when a communication terminal requests for allocation of the public IP address. The set top box(41-4n) manages public IP address allocated from the central station(1), mapping with private IP addresses fixedly allocated to the communication terminal. The communication terminals(511-51n, 5M1-5Mn) are combined with the set top box(41-4n) physically. If the set top box(41-4n) inputs a traffic message from an arbitrary communication terminal, the operator transmits the traffic message to the central station(1) based on a public IP address mapped on the private IP address. If a traffic message is received from the central station, the operator outputs traffic data to a corresponded communication terminal based on a private IP address mapped on a received public address.