US Patent 10587495 Hierarchical bit indexed replication of multicast packets

A hierarchical domain includes egress routers, an ingress router, set gateway routers, and subdomain gateway routers. The ingress router receives a multicast packet in a flow associated with the egress routers. The ingress router is in a first set of egress routers in a first subdomain of the hierarchical domain. The set gateway routers provide gateways to second sets of the plurality of egress routers in the first subdomain. The subdomain gateway routers provide gateways to second subdomains that includes sets of the plurality of egress routers. The ingress router generates a first copy of the multicast packet for transmission to the first set of egress routers based on a first bitstring, a second copy of the multicast packet for transmission to the set gateway routers based on a second bitstring, and a third copy of the multicast packet to the subdomain gateway routers based on a third bitstring.