Patent ID: 7978718

Claim:
A router that is interconnected to a source end station, comprising: a processor; and a memory configured to store: a data structure including a multicast distribution tree for a multicast group, the multicast distribution tree configured to specifically identify a path through a computer network from the router that is interconnected to the source end station to a destination end station, and software that, when executed by the processor of the router that is interconnected to the source end station, causes the router, upon receipt of a multicast data packet associated with the multicast group from the source end station, to encapsulate the received multi-cast data packet in a unicast data packet having a header, and to write the multicast distribution tree from the memory into the header of the encapsulating unicast data packet, to permit multicast transmission from the router to the destination end station, the multicast distribution tree represented in the header by a tree list and an address list, wherein the entries of the tree list are encoded according to a depth encoding scheme where the entries in the tree list are arranged in an order from parent to child and each of the entries of the tree list describes the depth of the network device in the multicast distribution tree, and wherein each the entries of the address list corresponds to the network device specified in one of the entries of the tree list and includes an address for the network device.