US Patent 10069639 Multicast systems and methods for segment routing

Multicast systems and methods for Segment Routing include receiving, at a node, a multicast packet including an outer label comprising a Multiprotocol Label Switching (MPLS) source node identifier defining a source-rooted broadcast tree and an inner label including a service identifier defining a service specific multicast tree; responsive to the node including a branch point on the source-rooted broadcast tree, popping the outer label, analyzing the inner label to identify active egress ports, pushing back the outer label, and forwarding the multicast packet to the active egress ports; and responsive to the node including point-to-point transit for the source-rooted broadcast tree, forwarding the multicast packet on the source-rooted broadcast tree.