Multicast with adaptive dual-state

• US 8,064,446 B2
• Filed: 04/01/2008
• Issued: 11/22/2011
• Est. Priority Date: 08/24/2007
• Status: Expired due to Fees

• Current Assignee: AT&T Intellectual Property I LP (AT&T, Inc.)
• Original Assignee: AT&T Intellectual Property I LP (AT&T, Inc.)
• Inventors: Ramakrishnan, Kadangode K., Cho, Tae W., Srivastava, Divesh, Zhang, Yin, Rabinovich, Michael
• Primary Examiner(s): Shah; Chirag
• Assistant Examiner(s): Van; Jenkey
• Application Number:
  US12/060,723
• Publication Number:
  US 20090052449A1
• Time in Patent Office: 1,330 Days
• Field of Search: None
• 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:

storing on a core node subscription information for a plurality of multicast members of a first multicast group;

receiving at the core node multicast traffic destined for the plurality of multicast members of the first multicast group;

determining a rate of the received multicast traffic;

unicasting the multicast traffic from the core node to the plurality of multicast members of the first multicast group over a membership tree including a first plurality of nodes connected in a first topology unless the determined rate of received multicast traffic exceeds a first threshold; and

multicasting the multicast traffic from the core node to the plurality of multicast members of the first multicast group over a dissemination tree including a second plurality of nodes connected in a second topology unless the determined rate of received multicast traffic does not exceed the first threshold, wherein the subscription information is provisioned to the plurality of multicast members of the first multicast group.

2. The method of claim 1, wherein the first plurality of nodes includes a third plurality of nodes used to access the 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 includes first hop node information that identifies a first node that communicates with the core node.

4. The method of claim 2, wherein the first plurality of nodes includes 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 at the core node of 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 third plurality of nodes and wherein the first plurality of nodes includes a first plurality of routers.

7. The method of claim 1, further comprising:

generating the dissemination tree responsive to the determined rate of the received multicast traffic exceeding the first threshold.

8. The method of claim 7, further comprising:

determining a second rate of additional multicast traffic received at the core node; and

deconstructing the dissemination tree responsive to the determined rate not exceeding the first predetermined rate.

9. The method of claim 7, wherein generating the dissemination tree includes using a core based tree protocol.

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

11. A device comprising a memory coupled to a controller, wherein the controller is adapted to:

store on a core node subscription information for a plurality of multicast members of a first multicast group;

receive at the core node multicast traffic destined for the plurality of multicast members of the first multicast group;

unicast the multicast traffic from the core node to the plurality of multicast members of the first multicast group over a membership tree including a first plurality of nodes connected in a first topology unless a rate of the received multicast traffic exceeds a first threshold; and

multicast the multicast traffic from the core node to the plurality of multicast members of the first multicast group over a dissemination tree including a second plurality of nodes connected in a second topology unless the rate of the received multicast traffic does not exceed the first threshold, wherein subscription information is provisioned to the plurality of multicast members of the first multicast group.

12. The device of claim 11, wherein the first plurality of nodes includes a third plurality of nodes used to access the subscriber information for the plurality of multicast members of the first multicast group.

13. The device of claim 12, wherein the first plurality of nodes includes first hop node information that identifies a first node that communicates with the core node.

14. The device of claim 12, wherein the first plurality of nodes includes child node information that identifies a branch in the first topology that includes the multicast members of the first multicast group.

15. The device of claim 11, wherein the multicast traffic is received from a first hop node.

16. The device of claim 11, wherein the first plurality of nodes is included in a base tree that includes a third plurality of nodes and wherein the first plurality of nodes includes a first plurality of routers.

17. The device of claim 11, wherein the controller is further adapted to generate the dissemination tree responsive to the first multicast traffic rate.

18. The device of claim 11, wherein the controller is further adapted to deconstruct the dissemination tree responsive to the second multicast traffic rate.

19. The device of claim 11, wherein the dissemination tree includes using the core based tree protocol.

20. A method comprising:

storing on a core node subscription information for a plurality of multicast members of a first multicast group;

receiving at the core node multicast traffic destined for the plurality of multicast members of the first multicast group;

unicasting multicast traffic from the core node to the plurality of multicast members of the first multicast group over a membership tree including a first plurality of nodes connected in a first topology unless a rate of the received multicast traffic exceeds a first threshold; and

multicasting the multicast traffic from the core node to the plurality of multicast members of the first multicast group over a dissemination tree including a second plurality of nodes connected in a second topology unless a rate of the received multicast traffic does not exceed a first threshold, wherein subscription information is provisioned to the plurality of multicast members of the first multicast group.

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

receive at a core node multicast traffic destined for a plurality of multicast members of a first multicast group;

storing on the core node subscription information for the plurality of multicast members of the first multicast group;

determine a rate of the received multicast traffic;

unicast the multicast traffic from the core node to the plurality of multicast members of the first multicast group over a membership tree including a first plurality of nodes connected in a first topology unless the determined rate of received multicast traffic exceeds a first threshold; and

multicast the multicast traffic from the core node to the plurality of multicast members of the first multicast group over a dissemination tree including a second plurality of nodes connected in a second topology unless the determined rate of received multicast traffic does not exceed the first threshold, wherein the subscription information is provisioned to the plurality of multicast members of the first multicast group.