MULTICASTING COMMUNICATION METHOD, SERVER DEVICE AND CLIENT DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a method and devices for multicasting communication using IGMP which facilitate management and control of receivers of the multicasting communication data. SOLUTION: This multicasting communication method includes a content server device allotting multicasting data, an IP layer routing device, a key management server device managing encoding and decoding keys, a reception management server device managing a client device, and the client device receiving the multicasting data. The content server device encodes the multicasting data and allots them onto an IP network, the client device requests the key management server device to give the decoding key, the key management server device inquires of the reception management server device whether the decoding key can be allotted or not, the reception management server device permits the allotment of the decoding key, the key management server device allots the decoding key to the client device, and the client device decodes the codes of the multicast data.