ON-DEMAND CONTENTS DISTRIBUTION SYSTEM

PROBLEM TO BE SOLVED: To provide an on-demand contents distribution system that allows a user to reproduce contents immediately after requesting the contents without the provision of a communication path exclusively for repeat broadcast. SOLUTION: The storage means 12 of a server 10 stores the identifiers of relaying devices 20 to be managed as to a generated multicast group as multicast group information, the names of contents distributed at present, and a reproduction possible period denoting a time when a client 30 takes part in a group and can receive data from the beginning of the contents or the like. When receiving contents distribution request from the client 30, an allocating means 13 informs the client 30 about the multicast group capable of distributing the contents from the beginning on the basis of the multicast group information.