Systems and Methods of Multicast Reconfiguration Using Cross-Layer Information

• US 20110019534A1
• Filed: 07/27/2009
• Published: 01/27/2011
• Est. Priority Date: 07/27/2009
• 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: Doverspike, Robert, Yuksel, Murat, Ramakrishnan, Kadangode
• Granted Patent: US 8,462,621 B2
• Time in Patent Office: Days
• US Class Current: 370/217
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/16 Multipoint routing
• CPC Class Codes: H04L 45/18 Loop-free operations
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04L 45/28 using route fault recovery
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06

Abstract

Systems and methods of multicast configuration are provided. A particular method includes detecting a failure in the data network at a first node of a data network. The method also includes determining an alternate route from the first node to a data source of the data network. The alternate route includes a second node as an upstream node. The method further includes determining whether the alternate route would create a loop in the data network. The method includes setting a state of the first node to a waiting-to-join the second node state when the alternate route would create a loop.

Claims

1. A method, comprising:

detecting, at a first node of a data network, a failure in the data network;

determining an alternate route from the first node to a data source of the data network, wherein the alternate route includes a second node as an upstream node;

determining whether the alternate route would create a loop in the data network and, when the alternate route would create a loop, setting a state of the first node to a waiting-to-join the second node state.

2. The method of claim 1, wherein when the alternate route would not create a loop, sending a join message to the second node.

3. The method of claim 1, further comprising sending a notice of the failure to at least one other node of the data network.

4. The method of claim 1, further comprising receiving data via a fast reroute (FRR) link of the data network.

5. The method of claim 1, further comprising:

receiving a prune message at the first node from a downstream node;

pruning a link to the downstream node;

determining that the state is set to the waiting-to-join the second node state; and

after pruning the link to the downstream node, sending a join message to the second node,

wherein the downstream node is the second node.

6. The method of claim 5, further comprising:

receiving data from the second node; and

after receiving the data, sending a FRR prune message to a node associated with a FRR link.

7. The method of claim 1, wherein determining whether the alternate route would create a loop in the data network includes determining whether the second node is a downstream node of the first node.

8. The method of claim 1, further comprising:

receiving fast reroute (FRR) data from another node via a FRR link; and

sending the FRR data to a downstream node;

after receiving a particular data packet, determining a transmission priority of the particular data packet, wherein data packets received via the FRR link have a lower priority than data packets not received via the FRR link; and

sending the particular data packet to the downstream node based on the transmission priority.

9. The method of claim 1, wherein detecting the failure in the data network includes receiving a link state advertisement from another node of the data network.

10. The method of claim 1, wherein determining the alternate route from the first node to the data source comprises determining a least cost route based on cost weights assigned to links of the data network.

11. The method of claim 1, wherein no data packets are lost as a result of the upstream failure other than data packets in transit when the upstream failure occurred.

12. The method of claim 1, wherein the failure in the data network occurs along a primary path of the first node and wherein the primary path of the first node is determined based on at least one of available bandwidth or the inverse of available bandwidth.

13. The method of claim 1, wherein the alternate route includes at least one link selected based on a high cost associated with at least one link.

14. The method of claim 1, further comprising:

detecting, at the first node of the data network, a second failure in the data network;

determining a second alternate route from the first node to the data source of the data network, wherein the second alternate route includes a third node as an upstream node and at least one data network loop; and

sending a join message to the third node.

15. A system, comprising:

a first network node, comprising;

a network interface to receive data from one or more upstream nodes of a data network, and to send the data to one or more downstream nodes of the data network based on a multicast tree; and

a routing module coupled to the network interface, the routing module to determine the multicast tree based on cost values associated with links of the data network from a data source to the first network node;

wherein, when the routing module determines a new multicast tree, the routing module determines whether the new multicast tree would create a loop in the data network, and when the new multicast tree would create a loop in the data network, the routing module stores a data record indicating a state of waiting-to-join a second network node, wherein the second network node is an upstream node of the first network node in the new multicast tree.

16. The system of claim 15, wherein, after receiving a prune message from a downstream node of the data network, the routing module sends a join message to the second network node, wherein the routing module determines the new multicast tree in response to a link state advertisement indicating a failure in the data network, and wherein the network interface is adapted to detect a failure of a link of the data network coupling the first network node directly to a downstream node of the data network.

17. The system of claim 16, further comprising a fast reroute (FRR) module to establish a FRR link to the downstream node via at least one second node of the data network using a label switching protocol.

18. The system of claim 16, wherein the FRR module assigns a reduced priority to data sent via the FRR link as compared to data sent based on the multicast tree.

19. The system of claim 15, wherein the first network node stores a network topology of the data network and a routing table that identifies connections between network nodes of the data network, shortest paths between the first network node and other network nodes of the data network, and a primary path from the first network node to a next hop node.

20. The system of claim 19, wherein the first network node stores an initial backup path to the primary path.

21. A computer-readable medium, comprising:

instructions that, when executed by a processor, cause the processor to determine an alternate route from a first node to a data source of a data network in response to an identified failure in the data network, wherein the alternate route includes a second node as an upstream node;

instructions that, when executed by the processor, cause the processor to determine whether the alternate route would create a loop in the data network; and

instructions that, when executed by the processor, cause the processor to set a state of the first node to waiting-to-join the second node when the alternate route would create a loop.

22. A method comprising:

receiving notice of an upstream failure of a data network;

determining an alternate route from a particular node to a data source of the data network;

receiving a data packet via the data network;

determining a transmission priority of the data packet;

sending the data packet to a downstream node of the data network based on the transmission priority of the data packet;

sending a first join message to a first upstream node of the data network;

sending a prune message to a second upstream node of the data network;

receiving a second join message from the second upstream node; and

adding a link to the second upstream node as a new downstream node of the data network.