Packet transfer apparatus

摘要

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 NW 2 such as the Internet. Data is transferred between a subscriber and the network through the L2TP connection. LNS 2 -i and sever S 1 are connected through network NW 2 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 S 1 on network NW 2 distributes multicast packets of a program or the like to the subscribers.