Patent ID: 7443851
Filing Date: 2008-10-28
Classification: H04L

Abstract:
1. In a multicast communication device receiving a multicast data packet from a multicast delivery server via a multicast router and forwarding the received data packet to a receiving terminal that is requesting reception of the data packet and that does not support multicast communication, the multicast communication device comprising: a unit for storing multicast request information including information required to receive multicast data packets; a unit for monitoring requests from the receiving terminal to receive multicast information sent by the multicast delivery server and for obtaining the contents of the requests when the requests are detected; a unit for storing multicast delivery server information relating to the multicast delivery server, the multicast delivery server information including an address of the multicast delivery server and addresses of receiving terminals subscribing to multicast groups associated with the multicast delivery server; a unit for comparing contents of a request obtained by monitoring requests from the receiving terminal with the multicast request information stored in the unit for storing multicast request information to determine if the request obtained by monitoring requests from the receiving terminal comprises a request to receive multicast information sent by the multicast delivery server; a unit for generating and sending a join group request to the multicast router including instructing the multicast router to route multicast data packets based on results of the comparison performed when the request is detected, wherein the join group request is not generated if at least one receiving terminal is already subscribed to receive multicast information sent by the multicast delivery server; and a unit for receiving data packets multicast from the multicast delivery server corresponding to the join group request, setting a destination address of the data packet to address information of the receiving terminal, and sending the received data packet to the receiving terminal.