Patent ID: 7639683
Filing Date: 2009-12-29
Classification: H04J,H04L

Abstract:
1. A communication method in a multicast communication network, including at least one Layer-2 switch interposed between two Layer-3 switches, for distributing multicast packets from a multicast transmitting terminal (source) through at least the Layer-2 switch to a plurality of multicast receiving terminals (receivers), comprising: forming a receiving terminal discrimination mechanism for discriminating multicast receiving terminals for receiving distribution of said multicast packets by using a discrimination packet, to be transmitted from said multicast receiving terminal to said multicast transmitting terminal when sending an IGMP-JOIN packet, for teaching said Layer-2 switch of an existence of the multicast receiving terminal requesting distribution of said multicast packets under the Layer-2 switch, the discrimination packet including an IP header and MAC header and wherein an IP source address and MAC source address are an IP address and MAC address of a multicast group to which said multicast receiving terminal belongs; and distributing multicast packets selectively by said receiving terminal discrimination mechanism only to multicast receiving terminals requesting distribution of said multicast packets when there are multicast receiving terminals relating to such requests under said Layer-2 switches, wherein each of said Layer-3 switches relays said multicast packets transmitted from said multicast transmitting terminal (source) through the Layer-2 switch and distributes them to said multicast receiving terminals requesting distribution of said multicast packets and transmits said discrimination packet, where each of the Layer-3 switches comprises a decision function unit for deciding if a received packet is the discrimination packet or a general packet other than the discrimination packet and a header processing function unit for processing the MAC header of said received packet and performing different processing in accordance with results of decision of said decision function unit.