An LAC manages multicast destinations, and forms and distributes copies of
the multicast packets. An L2TP tunnel and an L2TP session are formed
between LAC 1-i and LNS 2-i, and LNS 2-i is connected to network NW2 such
as the Internet. Data is transferred between a subscriber and the network
through the L2TP connection. LNS 2-i and sever S1 are connected through
network NW2 which has routers. A packet transfer apparatus enables LAC
1-i to manage subscriber information and to form and distribute copies of
the packets to the subscribers when server S1 on network NW2 distributes
multicast packets of a program or the like to the subscribers.