# US 9,143,333 B2 · System and method for multicast transmission > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,143,333 B2 - Document ID: US9143333B2 - Status: Granted - Kind: B2 - Application number: 14/337,920 - Filed: 2014-07-22 - Published: 2014-11-13 - Granted: 2015-09-22 - Earliest claimed: 2007-03-12 - Assignees: Upload Technologies S.A. - Applicants: Upload Technologies S.A. - Inventors: Robert E. Nimon; David E. Espenlaub; Francis Dinha; James Yonan - Web page: https://patentgrep.com/patent/US9143333B2 ## CPC - H04L 12/18: for broadcast or conference {, e.g. multicast} - H04L 45/02: Topology update or discovery - H04L 45/122: by minimising distances, e.g. by selecting a route with minimum of number of hops - H04L 45/16: Multipoint routing - H04L 45/04: {Interdomain routing, e.g. hierarchical routing} - H04L 45/42: Centralised routing - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A system and method for multicast transmission are disclosed. In one embodiment, a virtual exchange network including interconnected nodes is embedded within a network. A sender is disposed in communication with a root node and receivers are disposed in communication with a set of edge nodes. The sender publishes a packetized data stream to which the receivers subscribe. The packetized data stream is promulgated by implicit signaling through optimum virtual exchange network connections from the sender through the virtual exchange network to the receivers. The interconnected nodes, responsive to receiving the published packetized data stream, are adapted to multicast N instances of the published packetized data stream to N recipients selected from the group consisting of receivers and other of the interconnected nodes. ## Claims ### Claim 1 A system for multicast transmission of data over a network, the system comprising: a virtual exchange network embedded within the network, the virtual exchange network including a plurality of interconnected nodes; a plurality of sender-receivers disposed in communication with a set of edge nodes of the plurality of interconnected nodes, the plurality of sender-receivers configured to publish respective packetized data streams including virtual exchange network addresses, the plurality of sender-receivers configured to respectively subscribe to receive the published packetized data streams; a global multicast routing topology map disposed in the virtual exchange network, the global multicast routing topology map including an optimum virtual exchange network connection, the optimum virtual exchange network connection being defined by a pair of endpoints including at least two of the edge nodes of the set of edge nodes; and a plurality of local multicast routing topology maps disposed along the optimum virtual exchange network connection, each of the plurality of local multicast routing topology maps being a subset of the global multicast routing topology map to provide routing information for a defined area of the virtual exchange network, wherein the packetized data streams are propagated by implicit signaling through the optimum virtual exchange network connection according to the plurality of local multicast routing topology maps. ### Claim 2 (depends on 1) The system as recited in claim 1, wherein each of the plurality of interconnected nodes, responsive to receiving an instance of the published packetized data stream, is adapted to multicast N instances of the published packetized data stream to N recipients selected from the group consisting of receivers and other of the interconnected nodes. ### Claim 3 (depends on 2) The system as recited in claim 2, wherein each of the plurality of interconnected nodes aligned with the plurality of optimum virtual exchange network connections further comprises, for each of the N recipients, a port address and recipient identity associated with the virtual exchange network address. ### Claim 4 (depends on 1) The system as recited in claim 1, wherein each of the plurality of interconnected nodes aligned with the optimum virtual exchange network connection subscribes to receive the published packetized data streams successively regressively along the optimum virtual exchange network connection from one of the set of edge nodes to another of the edge nodes. ### Claim 5 (depends on 1) The system as recited in claim 1, wherein at least one of the edge nodes comprises a root node. ### Claim 6 (depends on 1) The system as recited in claim 1, wherein more than one of the plurality of sender-receivers subscribes to a particular one of the edge nodes. ### Claim 7 (depends on 1) The system as recited in claim 1, further comprising network elements for interconnecting the plurality of interconnected nodes, the network elements having the plurality of local multicast routing topology maps disposed therewith for routing the packetized data streams. ### Claim 8 (depends on 1) The system as recited in claim 1, further comprising a topology server subsystem disposed to communicate with the virtual exchange network, the topology server configured to generate the topology server subsystem. ### Claim 9 (depends on 8) The system as recited in claim 8, wherein the topology server subsystem executes a Dijkstra-based algorithm to calculate path costs and build the global multicast topology routing map. ### Claim 10 (depends on 8) The system as recited in claim 8, wherein the topology server subsystem recalculates the global multicast topology routing map in response to a virtual exchange network topology change. ### Claim 11 (depends on 10) The system as recited in claim 10, wherein the virtual exchange network topology change is selected from the group consisting of loss of a sender-receiver, addition of a sender-receiver, loss of a node, and addition of a node.