Patent ID: 8416777

Claim:
A method for transmitting multicast data packets from a multicast router, the method comprising: a) the multicast router receiving, via one or more downstream network interfaces, multicast data requests made by a host; b) the multicast router reading information data contained in the multicast data requests; c) the multicast router storing state data based on the information data contained in the multicast data requests for a first downstream network interface, a first multicast group address, and the host that requests multicast data of the first multicast group address from the first downstream network interface, the state data comprising: i) an INCLUDE state record, the INCLUDE state record comprising identifying data of the first downstream network interface through which the multicast router received the multicast data request, identifying data of the first multicast group address from which the multicast data has been requested, identifying data of the host from which the multicast data request has been received, a source list comprising source IP addresses and a source-timer associated with each source IP address, and an INCLUDE filter mode designator; or ii) an EXCLUDE state record, the EXCLUDE state record comprising identifying data of the first downstream network interface through which the multicast router received the multicast data request, identifying data of the first multicast group address from which the multicast data has been requested, identifying data of the host from which the multicast data request has been received, a source list comprising a requested list having source IP addresses with an associated source-timer having a value greater than zero and an exclude list comprising source IP addresses with an associated source-timer of value zero, and an EXCLUDE filter mode designator; d) the multicast router storing one or more of the INCLUDE state records for the first downstream network interface and the first multicast group address; and e) the multicast router transmitting, through the first downstream network interface, at least the multicast data packets which have as a destination IP address the first multicast group address and which have as a source IP address any source IP address from the union of all the source lists stored in the INCLUDE state records of the first downstream network interface and the first multicast group address and having a source-timer greater than zero.