Patent ID: 8094602
Filing Date: 2012-01-10
Classification: H04L

Abstract:
1. A method implemented by a multicast router having one or more downstream network interfaces and 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 the sources, the method comprising: the multicast router storing for a downstream network interface and multicast group address at least one INCLUDE source record containing information about include source lists derived by data requests made by the one or more hosts and at least one EXCLUDE source record containing information about exclude source lists derived by data requests made by the one or more hosts, 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, the multicast router maintaining a source-timer for each of the sources in the include and exclude source lists, the multicast router transmitting for the network interface and 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, the multicast router transmitting for each INCLUDE source of a multicast group address having a source-timer of a value greater than zero multicast packets through the downstream network interface and also transmitting multicast packets of the sources of the multicast group address through the network interface except the EXCLUDE sources having a source timer of a value zero.