Patent ID: 8559427
Filing Date: 2013-10-15
Classification: H04L

Abstract:
1. A method implemented in a network element in a wide area network, the network element functioning as a proxy for an upstream multicast router using internet group management protocol (IGMP) or Multicast Listener Discovery (MLD) to provide a plurality of multicast sources to a plurality of multicast subscriber nodes, the plurality of multicast subscriber nodes in communication with the network element, the method to efficiently and scalably manage an interface between the upstream multicast router and the proxy by tracking a subset of multicast sources from the plurality of multicast sources required by an aggregate state of the plurality of multicast subscriber nodes, the tracking using an interface tracking table for determining the aggregate state for the interface instead of a forwarding information base (FIB) and membership database that tracks more specific data detailing each multicast source required by each multicast subscriber node, the method comprising the steps of: receiving an IGMP or MLD membership report by the network element from a first of the plurality of multicast subscriber nodes, the IGMP or MLD membership report indicating at least one change in the set of multicast sources to be received by the first multicast subscriber node on the interface between the network element and the upstream multicast router; updating the interface tracking table to reflect the at least one change in the subset of multicast sources, the interface tracking table corresponding to the interface between the network element and the upstream multicast router and maintaining the aggregate state of the plurality of multicast subscriber nodes, the aggregate state defining the subset of multicast sources to be forwarded to or blocked from the plurality of multicast subscriber nodes; and notifying the upstream multicast router of the at least one change in the subset of multicast sources to be forwarded to or blocked from the network element based on the updating of the interface tracking table, the updating of the interface tracking table being independent of the updating of the FIB and membership database that maintains multicast sources to be forwarded and blocked for each multicast subscriber node.