Patent ID: 7533185

Claim:
A data communication method for sending and receiving packet data between a plurality of computers connected to each other via a network, wherein each of said computers includes a multicast sending part sending packet data between said computers in a multicast form, a multicast receiving part receiving said packet data, and a connection type data sending and receiving part sending and receiving data to and from another computer of the computers in a one-to-one unicast form, the data communication method comprising: communicating an encapsulated document including at least a digital information file, a display information file, and an operation program file, which operation program file includes a communicating program, wherein said multicast sending part, said multicast receiving part, and said connection type data sending and receiving part in respective of the computers are executed by causing said respective computers to read the communicating program of the operation program file in the encapsulated document; establishing a unicast communication in which one computer of said computers designates another computer of said computers and establishes a communication to the another computer in the one-to-one unicast form when data are sent between said computers, based on the communication program in the encapsulated document causing the one computer and the another computer to execute at least their respective connection type data sending and receiving parts; and establishing a multicast communication from one of said computers to at least one other of the computers, based on the communication program in the encapsulated document causing the one computer and the at least one other of the computers to execute at least their respective multicast sending parts and multicast receiving parts.