MULTICAST WITH ADAPTIVE DUAL-STATE

• US 20090052449A1
• Filed: 04/01/2008
• Published: 02/26/2009
• Est. Priority Date: 08/24/2007
• Status: Active Grant

• Current Assignee: AT&T Intellectual Property I LP (AT&T, Inc.)
• Original Assignee: AT&T Intellectual Property I LP (AT&T, Inc.)
• Inventors: Srivastava, Divesh, Zhang, Yin, Ramakrishnan, Kadangode K., Rabinovich, Michael, Cho, Tae Won
• Granted Patent: US 8,064,446 B2
• Time in Patent Office: Days
• US Class Current: 370/390
• CPC Class Codes: H04L 12/1886 with traffic restrictions for efficiency improvement, e.g. involving subnets or subdomains
• CPC Class Codes: H04L 45/16 Multipoint routing
• CPC Class Codes: H04L 45/48 Routing tree calculation

Abstract

A method and system are described to multicast with an adaptive dual state. The system receives multicast traffic over a membership tree including a first plurality of nodes connected in a first topology destined for a plurality of multicast members of a first multicast group. Next, the system determines a rate of multicast traffic that exceeds a predetermined threshold based on the receiving the multicast traffic. Next, the system generates a dissemination tree including a second plurality of nodes connected in a second topology to reduce a number of hops to communicate the multicast traffic to the plurality of multicast members of the first multicast group. Finally, the system forwards the multicast traffic to the plurality of multicast members of the first multicast group over the dissemination tree.

Claims

1. A method comprising:

receiving multicast traffic over a membership tree including a first plurality of nodes connected in a first topology, the multicast traffic destined for a plurality of multicast members of a first multicast group;

determining a rate of multicast traffic that exceeds a first predetermined threshold based on the receiving the multicast traffic;

generating a dissemination tree including a second plurality of nodes connected in a second topology, the generating to reduce a number of hops to communicate the multicast traffic to the plurality of multicast members of the first multicast group; and

forwarding the multicast traffic to the plurality of multicast members of the first multicast group over the dissemination tree.

2. The method of claim 1, wherein the first plurality of nodes includes a third plurality of nodes used to access subscriber information for the plurality of multicast members of the first multicast group.

3. The method of claim 2, wherein the first plurality of nodes include first hop node information that identifies a first node that communicates with a first multicast member of the first multicast group.

4. The method of claim 2, wherein the first plurality of nodes include topology branch information that identifies a branch in the first topology that includes the multicast members of the first multicast group.

5. The method of claim 1, wherein the receiving the multicast traffic includes receiving the multicast traffic from a first hop node.

6. The method of claim 1, wherein the first plurality of nodes is included in a base tree that includes a fourth plurality of nodes and wherein the first plurality of nodes includes a first plurality of routers

7. The method of claim 1, wherein the second plurality of nodes respectively stores interface information that identifies interfaces for multicasting the multicast traffic.

8. The method of claim 1, further comprising:

determining a second rate of multicast traffic is less than the first predetermined threshold;

deconstructing the second dissemination tree responsive to the determination; and

communicating the multicast traffic over the membership tree.

9. The method of claim 8, wherein the communicating the multicast traffic includes unicasting the multicast traffic over the membership tree.

10. The method of claim 1, wherein the generating includes using the Core Based Tree Protocol to generate the dissemination tree.

11. The method of claim 1, further including forwarding the multicast traffic from a first domain including a second plurality of nodes to a second domain including a third plurality of nodes, wherein the first domain is associated with the first predetermined threshold and the second domain is associated with a second predetermined threshold, wherein the first predetermined threshold is different from the second predetermined threshold.

22. The system of claim 1, wherein the processing module forwards the multicast traffic from a first domain including a second plurality of nodes to a second domain including a third plurality of nodes, wherein the first domain is associated with the first predetermined threshold and the second domain is associated with a second predetermined threshold used, wherein the first predetermined threshold is different from the second predetermined threshold.

12. A system comprising:

a receiving module to receive multicast traffic over a membership tree including a first plurality of nodes connected in a first topology, the multicast traffic destined for a plurality of multicast members of a first multicast group; and

a processing module to determine a rate of multicast traffic that exceeds a predetermined threshold based on the receiving the multicast traffic, the processing module to generate a dissemination tree including of a second plurality of nodes connected in a second topology to reduce a number of hops to communicate the multicast traffic to the plurality of multicast members of the first multicast group, the processing module to forward the multicast traffic to the plurality of multicast members of the first multicast group over the dissemination tree.

13. The system of claim 12, wherein the first plurality of nodes includes a third plurality of nodes used to access subscriber information for the plurality of multicast members of the first multicast group.

14. The system of claim 13, wherein the first plurality of nodes include first hop node information that identifies a first node that communicates with a first multicast member of the first multicast group.

15. The system of claim 13, wherein the first plurality of nodes include child node information that identifies a branch in the first topology that includes the multicast members of the first multicast group.

16. The system of claim 12, wherein the receiving module is to receive the multicast traffic from a first hop node.

17. The system of claim 12, wherein the first plurality of nodes is included in a base tree that includes a fourth plurality of nodes and wherein the first plurality of nodes includes a first plurality of routers.

18. The system of claim 12, wherein the second plurality of nodes respectively stores interface information that identifies interfaces for multicasting the multicast traffic.

19. The system of claim 12, wherein the processing module is to determine whether a second rate of multicast traffic is less than a predetermined threshold, deconstruct the second dissemination tree responsive to the determination and communicate the multicast traffic over the membership tree.

20. The system of claim 19, wherein the processing module is to unicast the multicast traffic over the membership tree.

21. The system of claim 12, wherein the processing module generating uses the Core Based Tree Protocol to generate the dissemination tree.

23. A system comprising:

a first means for receiving multicast traffic over a membership tree including a first plurality of nodes connected in a first topology destined for a plurality of multicast members of a first multicast group; and

a second means for determining a rate of multicast traffic that exceeds a predetermined threshold based on the receiving the multicast traffic, the second means to generate a dissemination tree including a second plurality of nodes connected in a second topology to reduce a number of hops to communicate the multicast traffic to the plurality of multicast members of the first multicast group, the second means to forward the multicast traffic to the plurality of multicast members of a first multicast group over the dissemination tree.

24. A machine-readable medium storing instructions that, when executed by a machine, cause the machine to:

receive multicast traffic over a membership tree including a first plurality of nodes connected in a first topology destined for a plurality of multicast members of a first multicast group;

determine a rate of multicast traffic that exceeds a predetermined threshold based on the receiving the multicast traffic;

generate a dissemination tree including a second plurality of nodes connected in a second topology, the generating to reduce a number of hops to communicate the multicast traffic to the plurality of multicast members of the first multicast group; and

forward the multicast traffic to the plurality of multicast members of the first multicast group over the dissemination tree.