Patent ID: 7558219

Claim:
A method comprising: establishing a multicast tree comprising a point-to-multipoint (P2MP) label switched path (LSP) forming a P2MP tunnel, the P2MP tunnel having a source device providing an ingress to the P2MP tunnel and a plurality of destination devices providing a plurality of different egresses from the P2MP tunnel, wherein each of the destination devices belongs to at least one virtual private local area network service (VPLS) multicast instance; and transmitting multicast data packets for the VPLS multicast instances from the source device through the P2MP tunnel to the destination devices on the multicast tree, wherein establishing the multicast tree comprises: discovering, with the source device, the VPLS multicast instances of which the destination devices are members; mapping more than one of the discovered VPLS multicast instances to the multicast tree; allocating an inner label with the source device for each of the more than one VPLS multicast instances mapped to the multicast tree; advertising mapping information from the source device to the one or more destination devices, wherein the mapping information specifies which of the discovered VPLS multicast instances are mapped to the multicast tree; with the source device, including the allocated inner labels within the mapping information advertised from the source device to the destination devices to allow the destination devices to demultiplex the multicast data packets received over the multicast tree; in response to the mapping information advertised by the source device, maintaining, within each destination device, a separate label space for the multicast tree, wherein the label space within each destination device includes forwarding entries for the inner labels allocated by the source device, and wherein transmitting the multicast data packets from the source device comprises encapsulating each of the multicast data packets at the source device with an outer label and one of the inner labels, wherein the outer label identifies the label space within the destination device that corresponds to the multicast tree, and wherein the inner label is based on the VPLS multicast instance with which the multicast data packet is associated.