Patent ID: 7640333

Claim:
A multicast router situated in a data network system between sources that send multicast packets to at least one multicast group address and one or more hosts that request data from the multicast group address and sources, the multicast router comprising: one or more downstream network interfaces; a storage medium that stores for a downstream network interface and multicast group address at least one INCLUDE source record and at least one EXCLUDE source record, the INCLUDE source record containing information about include source lists derived by data requests made by the one or more hosts and the EXCLUDE source record containing information about exclude source lists derived by data requests made by the one or more hosts; a source-timer for each of the sources in the include and exclude source lists, the exclude source lists including a Requested List containing a list of sources having a source-timer of a value greater than zero and an Exclude List containing a list of sources having a source-timer of a value zero; and wherein the downstream network interface transmits for each multicast group address multicast packets to the hosts based on the information of the at least one INCLUDE source record and the at least one EXCLUDE source record by transmitting for each INCLUDE source of a multicast group address having a source-timer of a value greater than zero multicast packets through the network interface and also transmitting multicast packets of the remaining sources of the multicast group address through the network interface except the EXCLUDE sources from the Exclude List; and the multicast router using a host-router multicast routing protocol based on the IGMP (Internet Group Management Protocol) or the MLD (Multicast Listener Discovery) protocol to communicate with the one or more hosts and a router-router multicast routing protocol to communicate with at least one other multicast router situated between the multicast router and the sources.