# US 2021/0243111 A1 · Supporting multicast communications > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0243111 A1 - Document ID: US20210243111A1 - Status: Published application - Kind: A1 - Application number: 16/781,376 - Filed: 2020-02-04 - Published: 2021-08-05 - Earliest claimed: 2020-02-04 - Assignees: Nokia Solutions and Networks Oy - Applicants: Nokia Solutions and Networks Oy - Inventors: Pranjal Kumar Dutta - Web page: https://patentgrep.com/patent/US20210243111A1 ## CPC - H04L 45/16: Multipoint routing - H04L 12/08: Allotting numbers to messages; Counting characters, words or messages - H04L 12/4641: {Virtual LANs, VLANs, e.g. virtual private networks [VPN] (LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272)} - H04L 45/24: Multipath - H04L 45/34: {Source routing} - H04L 45/48: Routing tree calculation - H04L 45/50: using label swapping, e.g. multi-protocol label switch [MPLS] - H04L 45/74: Address processing for routing - H04L 63/0272: {Virtual private networks} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Various example embodiments for supporting multicast communications in a communication system are presented. Various embodiments for supporting multicast communications may be configured to support multicast communications of multiple virtual private networks over a single multicast distribution tree. Various embodiments for supporting multicast communications of multiple virtual private networks over a single multicast distribution tree may support communication of a packet of a virtual private network within a network, wherein the packet includes a set of tuples associated with a set of egress devices to which the packet is to be delivered via a multicast distribution tree supported within the network, wherein, for each of the egress devices, the respective tuple associated with the respective egress device includes a respective device identifier of the egress device that uniquely identifies the respective egress device within the network and a respective label assigned by the respective egress device for the virtual private network. ## Claims ### Claim at position 1 1-20. (canceled) ### Claim 21 An apparatus, comprising: at least one processor; and at least one memory including a set of instructions; wherein the set of instructions is configured to, when executed by the at least one processor, cause the apparatus to: support communication of a packet of a virtual private network within a network, wherein the packet includes a tuple associated with an egress device to which the packet is to be delivered via a multicast distribution tree supported within the network, wherein the tuple includes a device identifier of the egress device that uniquely identifies the egress device within the network and a label assigned by the egress device for the virtual private network. ### Claim 22 (depends on 21) The apparatus of claim 21, wherein the device identifier of the egress device is determined by the egress device based on communication with at least one other egress device. ### Claim 23 (depends on 21) The apparatus of claim 21, wherein the device identifier of the egress device is determined by the egress device based on communication with a network controller. ### Claim 24 (depends on 21) The apparatus of claim 21, wherein the device identifier of the egress device comprises an index assigned from a unique index space of the network. ### Claim 25 (depends on 24) The apparatus of claim 24, wherein the unique index space of the network is based on a sorting of a respective set of addresses of a respective set of devices of the network. ### Claim 26 (depends on 24) The apparatus of claim 24, wherein the tuple is encoded within the packet based on an indexed label stack including an encoding of the tuple and an indexed label stack identifier configured to indicate a presence of the indexed label stack within the packet. ### Claim 27 (depends on 26) The apparatus of claim 26, wherein the encoding of the indexed label stack includes: an index bit string having a set of bit positions corresponding to a respective set of devices of the network, wherein one of the bit positions corresponding to the index of the egress device is set; and a label stack encoding the label assigned by the egress device for the virtual private network. ### Claim 28 (depends on 27) The apparatus of claim 27, wherein the label assigned by the egress device for the virtual private network is positioned within the label stack based on a position of the index of the egress device within the index bit string. ### Claim 29 (depends on 26) The apparatus of claim 26, wherein the encoding of the indexed label stack includes: a label pair for the tuple, wherein the label pair for the tuple includes a first label encoding the index of the egress device and a second label encoding the label assigned by the egress device for the virtual private network. ### Claim 30 (depends on 21) The apparatus of claim 21, wherein to support communication of the packet within the network, the set of instructions is configured to, when executed by the at least one processor, cause the apparatus to: receive the packet at an ingress device of the network via an access link of the ingress device; determine, based on the access link, that the packet is associated with the virtual private network; and forward the packet from the ingress device of the network toward a second device of the network based on a next-hop label configured to identify the second device in the multicast distribution tree. ### Claim 31 (depends on 30) The apparatus of claim 30, wherein, to forward the packet, the set of instructions is configured to, when executed by the at least one processor, cause the apparatus to: generate a multicast packet including the packet and including the next-hop label configured to identify the second device in the multicast distribution tree; and forward the multicast packet from the ingress device of the network toward the second device of the network. ### Claim 32 (depends on 21) The apparatus of claim 21, wherein, to support communication of the packet within the network, the set of instructions is configured to, when executed by the at least one processor, cause the apparatus to: receive, at a transit device of the network, a multicast packet including the packet and including a next-hop label identifying the transit device; and forward the packet from the transit device toward a second device of the network. ### Claim 33 (depends on 32) The apparatus of claim 32, wherein, to forward the packet, the set of instructions is configured to, when executed by the at least one processor, cause the apparatus to: determine, based on a lookup based on the next-hop label, a next-hop label identifying the second device; create, based on the lookup based on the next-hop label, a copy of the multicast packet; swap the next-hop label identifying the transit device with the next-hop label identifying the second device in the copy of the multicast packet to form thereby a new multicast packet; and forward the new multicast packet from the transit device toward the second device based on the next-hop label identifying the second device. ### Claim 34 (depends on 21) The apparatus of claim 21, wherein to support communication of the packet within the network, the set of instructions is configured to, when executed by the at least one processor, cause the apparatus to: receive the packet at the egress device; identify, based on the device identifier of the egress device, the tuple including the device identifier of the egress device; identify, based on the tuple including the identifier of the egress device, the label assigned by the egress device for the virtual private network; and forward the packet from the egress device based on the label assigned by the egress device for the virtual private network. ### Claim 35 (depends on 34) The apparatus of claim 34, wherein, to forward the packet, the set of instructions is configured to, when executed by the at least one processor, cause the apparatus to: determine, based on a lookup based on the label assigned by the egress device for the virtual private network, that the packet is associated with the virtual private network; and forward the packet network from the egress device based on a forwarding table of the virtual private network. ### Claim 36 (depends on 21) The apparatus of claim 21, wherein the multicast distribution tree is selected from a set of available multicast distribution trees of the network based on a determination that a set of leaf devices of the multicast distribution tree includes a set of egress devices to which the packet is to be delivered. ### Claim 37 (depends on 21) The apparatus of claim 21, wherein the set of instructions is configured to, when executed by the at least one processor, cause the apparatus to: support communication of a second multicast packet associated with a second virtual private network using the multicast distribution tree. ### Claim 38 (depends on 21) The apparatus of claim 21, wherein the set of instructions is configured to, when executed by the at least one processor, cause the apparatus to: support communication of a second packet intended for delivery to the egress device, wherein the second packet is a unicast packet of the virtual private network, wherein the second packet includes the label assigned by the egress device for the virtual private network. ### Claim 39 A non-transitory computer-readable medium storing instructions which, when executed by at least one processor of an apparatus, cause the apparatus to: support communication of a packet of a virtual private network within a network, wherein the packet includes a tuple associated with an egress device to which the packet is to be delivered via a multicast distribution tree supported within the network, wherein the tuple includes a device identifier of the egress device that uniquely identifies the egress device within the network and a label assigned by the egress device for the virtual private network. ### Claim 40 A method, comprising: supporting communication of a packet of a virtual private network within a network, wherein the packet includes a tuple associated with an egress device to which the packet is to be delivered via a multicast distribution tree supported within the network, wherein the tuple includes a device identifier of the egress device that uniquely identifies the egress device within the network and a label assigned by the egress device for the virtual private network.