Methods and systems to store state used to forward multicast traffic

• US 8,649,377 B2
• Filed: 10/20/2011
• Issued: 02/11/2014
• 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, Srivastava, Divesh, Cho, Tae W., Zhang, Yin, Rabinovich, Michael
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): Boakye, Alexander O
• Application Number:
  US13/277,865
• Publication Number:
  US 20120033582A1
• Time in Patent Office: 845 Days
• Field of Search: 370/390, 370/432, 370/401, 370/389, 370/397, 370/449, 370/469, 370/400, 370/409, 370/489, 370/255, 370/253, 370/270
• 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, by a core node device comprising a processor, at a communication network a message intended for a multicast group associated with a first plurality of node devices of the communication network, wherein the communication network comprises a communication tree and comprises the core node device, the first plurality of node devices, and a second plurality of node devices;

determining, by the core node device, a distribution mode for the communication network;

sending, by the core node device, a multicast message from the core node device to the first plurality of node devices through at least a first portion of the second plurality of node devices responsive to a first determination that the distribution mode of the communication network is active, wherein membership state information for the multicast group is stored at the core node device and at the first portion of the second plurality of nodes; and

sending, by the core node device, a unicast message from the core node device to the first plurality of node devices through a second portion of the second plurality of node devices responsive to a second determination that the distribution mode of the communication network is inactive, wherein the membership state information for the multicast group is stored at the core node device and a first node device of the second plurality of node devices.

2. The method of claim 1, wherein the message received at the core node device is from a first hop node device of the communication network.

3. The method of claim 2, wherein the core node device is identified according to a hashing algorithm performed on the message at the first hop node device.

4. The method of claim 2, wherein the multicast group is associated with the first plurality of node devices as a result of members of the multicast group accessing the first plurality of node devices.

5. The method of claim 1, comprising:

receiving, by the core node device, a plurality of messages;

determining, by the core node device, a rate of the plurality of messages received; and

comparing, by the core node device, the rate to a threshold.

6. The method of claim 5, wherein the distribution mode of the communication network is determined to be active responsive to the rate exceeding the threshold.

7. The method of claim 5, wherein the distribution mode of the communication network is determined to be inactive responsive to the rate not exceeding the threshold.

8. The method of claim 1, comprising sending the multicast message, by the core node device, to the first plurality of node devices through a portion of the second plurality of node devices according to a core based tree protocol responsive to the determination that the distribution mode of the communication network is active.

9. A device comprising a memory to store executable instructions and coupled to a controller, wherein the controller, responsive to executing the executable instructions, performs operations comprising:

determining a distribution mode for a message through a communication network, wherein the communication network comprises a communication tree and comprises the device, a first plurality of node devices associated with a multicast group, and a second plurality of node devices;

multicasting the message to the first plurality of node devices through the second plurality of node devices responsive to a determination that the distribution mode of the communication network is active, wherein membership state information is stored at the device and at the second plurality of node devices; and

unicasting the message to the first plurality of node devices through a portion of the second plurality of node devices responsive to a determination that the distribution mode of the communication network is inactive, wherein the membership state information is stored at the device and at a first node device of the second plurality of node devices.

10. The device of claim 9, wherein the message is received at the device from a first hop node device of the communication network.

11. The device of claim 10, wherein the first hop node device is identified in the membership state information.

12. The device of claim 10, wherein the device is identified by a hashing algorithm performed on the message at the first hop node device.

13. The device of claim 9, wherein the controller further performs operations comprising:

receiving a plurality of messages;

determining a rate of the plurality of messages received; and

comparing the rate to a threshold.

14. The device of claim 13, wherein the distribution mode of the communication network is determined to be active responsive to the rate exceeding the threshold.

15. The device of claim 13, wherein the distribution mode of the communication network is determined to be inactive responsive to the rate not exceeding the threshold.

16. The device of claim 9, wherein the controller further performs operations comprising sending the message that is multicast from the device to the first plurality of node devices through the second plurality of node devices according to a core based tree protocol responsive to the determination that the distribution mode of the communication network is active.

17. A non-transitory computer-readable storage medium comprising instructions, which when executed by a processor, cause the processor to perform operations comprising:

receiving a plurality of messages;

determining a rate of the plurality of messages received; and

comparing the rate to a threshold,

determining a distribution mode of a communication network, wherein the communication network comprises a communication tree and comprises a first plurality of node devices and a second plurality of node devices and wherein the distribution mode is determined according to the comparing of the rate to the threshold; and

according to the determination of the distribution mode of the communication network;

distributing a multicast message to the first plurality of node devices through at least a first portion of the second plurality of node devices by one of multicasting or unicasting; and

storing membership information at a second portion the second plurality of nodes.

18. The non-transitory storage medium of claim 17, wherein the distribution mode of the communication network is determined to be active responsive to the rate exceeding the threshold.

19. The non-transitory storage medium of claim 17, wherein the distribution mode of the communication network is determined to be inactive responsive to the rate not exceeding the threshold.