Method and devices for multicasting

摘要

A server device used in a mobile communication system which transfers a multicast packet sent from a sending terminal to a receiving terminal through a packet transfer network, includes: a multicast tree determination unit configured to determine a multicast tree showing a transfer route of the multicast packet; and an instruction unit configured to instruct a multicast-corresponding router within the packet transfer network to prepare a multicast transfer table used for transferring the multicast packet, in accordance with a determined multicast tree.