Patent ID: 7388877
Filing Date: 2008-06-17
Classification: H04L

Abstract:
1. A packet transfer apparatus for terminating Layer 2 Tunneling Protocol (L2TP), disposed on a subscriber side of a network in which an L2TP tunnel and an L2TP session are formed, the packet transfer apparatus comprising: an LNS-multicast group information table for storing an L2TP network server (LNS) address to which a multicast L2TP connection is made, an L2TP connection established flag, an upstream L2TP tunnel identifier, and an upstream L2TP session identifier, for the address of an LNS which a subscriber terminal belongs to and the address of a multicast group; an L2TP decapsulation table for storing a multicast session flag, which indicates whether a multicast L2TP connection is made, for an LAC address, a downstream L2TP tunnel identifier, and a downstream L2TP session identifier; a multicast table for storing line information including the information of an output port and an output interface to which copies of multicast packets are distributed, for a multicast LNS address and a multicast group address; and a protocol processing unit which can access each of the tables and is connected to a network through an interface, the protocol processing unit comprising: