REROUTING TUNNEL TRAFFIC IN COMMUNICATION NETWORKS

• US 20160099865A1
• Filed: 10/07/2014
• Published: 04/07/2016
• Est. Priority Date: 10/07/2014
• 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: Klincewicz, John Gregory, Choudhury, Gagan, Meier-Hellstern, Kathleen S.
• Granted Patent: US 9,954,770 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 43/0817 by checking functioning
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04L 45/28 using route fault recovery
• CPC Class Codes: H04L 47/41 by acting on aggregated flows or links

Abstract

Methods, apparatus, systems and articles of manufacture (e.g., physical storage media) to reroute tunnel traffic in a network are disclosed. Example methods disclosed herein include, in response to detecting an event associated with routing first traffic in the network, determining a plurality of paths to carry respective traffic for a plurality of tunnels between pairs of routers in the network, the plurality of paths being determined based on a quality metric characterizing an aggregate tunnel bandwidth to be carried by the plurality of paths for the plurality of tunnels. Such disclosed example methods also include sending first routing information describing the plurality of paths to the routers in the network to cause the routers to route the respective traffic for the plurality of tunnels using the plurality of paths.

Claims

1. A method to reroute tunnel traffic in a network, the method comprising:

in response to detecting an event associated with routing first traffic in the network, determining, with a processor, a plurality of paths to carry respective traffic for a plurality of tunnels between pairs of routers in the network, the plurality of paths being determined based on a quality metric characterizing an aggregate tunnel bandwidth to be carried by the plurality of paths for the plurality of tunnels; and

sending first routing information describing the plurality of paths to the routers in the network to cause the routers to route the respective traffic for the plurality of tunnels using the plurality of paths, at least some of the first routing information to replace second routing information previously determined at a first one of the routers in response to the event associated with routing the first traffic.

2. The method of claim 1, wherein determining the plurality of paths comprises:

determining a first plurality of candidate paths to carry the respective traffic for the plurality of tunnels, respective ones of the plurality of tunnels associated with respective tunnel sizes;

determining a first value of the quality metric representing a first aggregate tunnel bandwidth carried by the first plurality of candidate paths; and

determining the first routing information to describe the first plurality of candidate paths when the first value of the quality metric corresponds to a sum of the respective tunnel sizes associated with the respective ones of the plurality of tunnels.

3. The method of claim 2, wherein when the first value of the quality metric does not correspond to the sum of the respective tunnel sizes associated with the respective ones of the plurality of tunnels, determining the plurality of paths further comprises:

determining a second plurality of candidate paths to carry the respective traffic for the plurality of tunnels;

determining a second value of the quality metric representing a second aggregate tunnel bandwidth carried by the second plurality of candidate paths; and

determining the first routing information to describe the second plurality of candidate paths when the second value of the quality metric does not correspond to the sum of the respective tunnel sizes associated with the respective ones of the plurality of tunnels and the second value of the quality metric exceeds the first value of the quality metric.

4. The method of claim 3, wherein the first plurality of candidate paths is determined based on a first ordering of the plurality of tunnels, and the second plurality of candidate paths is determined based on a second ordering of the plurality of tunnels different from the first ordering of the plurality of tunnels.

5. The method of claim 2, wherein determining the first plurality of candidate paths comprises:

determining whether a first candidate path capable of supporting a first tunnel size associated with a first one of the plurality of tunnels is available in the network; and

in response to determining the first candidate path is available;

setting a routed bandwidth value for the first one of the plurality of tunnels equal to the first tunnel size; and

decreasing available link capacities of a first set of network links included in the first candidate path by the first tunnel size.

6. The method of claim 5, further comprising, in response to determining that the first candidate path is not available:

determining whether a second candidate path capable of supporting a portion of the first tunnel size associated with the first one of the plurality of tunnels is available in the network; and

in response to determining the second candidate path is available;

setting the routed bandwidth value for the first one of the plurality of tunnels equal to the portion of the first tunnel size; and

decreasing available link capacities of a second set of network links included in the second candidate path by the portion of the first tunnel size.

7. The method of claim 6, wherein determining the first value of the quality metric comprises increasing the first value of the quality metric by the routed bandwidth value for the first one of the plurality of tunnels.

8. The method of claim 1, wherein the processor is included in a controller separate from the routers in the network, the plurality of tunnels corresponds to a first plurality of tunnels evaluated during a first processing iteration, the plurality of paths corresponds to a first plurality of paths, and further comprising:

accessing state information reported by the routers to determine respective amounts of traffic to be supported between the pairs of the routers in the network for different classes of service;

processing the state information and a largest tunnel size parameter to determine the first plurality of tunnels to be examined during the first processing iteration;

determining a tunnel ordering for the first processing iteration;

determining the first plurality of paths during the first processing iteration based on the tunnel ordering, the first plurality of tunnels and the first plurality of paths being included in a first rerouting solution associated with a first value of the quality metric;

varying at least one of the tunnel ordering and the largest tunnel size parameter among subsequent processing iterations to determine different rerouting solutions comprising different pluralities of tunnels having respective different pluralities of paths, the different rerouting solutions associated with different values of the quality metric; and

selecting, based on the different values of the quality metric, one of the different rerouting solutions to be used to determine the first routing information.

9. A tangible machine readable storage medium comprising machine readable instructions which, when executed, cause a machine to perform operations comprising:

in response to detecting an event associated with routing first traffic in a network, determining a plurality of paths to carry respective traffic for a plurality of tunnels between pairs of routers in the network, the plurality of paths being determined based on a quality metric characterizing an aggregate tunnel bandwidth to be carried by the plurality of paths for the plurality of tunnels; and

sending first routing information describing the plurality of paths to the routers in the network to cause the routers to route the respective traffic for the plurality of tunnels using the plurality of paths, at least some of the first routing information to replace second routing information previously determined at a first one of the routers in response to the event associated with routing the first traffic.

10. The tangible machine readable storage medium of claim 9, wherein determining the plurality of paths comprises:

determining a first plurality of candidate paths to carry the respective traffic for the plurality of tunnels, respective ones of the plurality of tunnels associated with respective tunnel sizes;

determining a first value of the quality metric representing a first aggregate tunnel bandwidth carried by the first plurality of candidate paths; and

determining the first routing information to describe the first plurality of candidate paths when the first value of the quality metric corresponds to a sum of the respective tunnel sizes associated with the respective ones of the plurality of tunnels.

11. The tangible machine readable storage medium of claim 10, wherein the first plurality of candidate paths is determined based on a first ordering of the plurality of tunnels, and when the first value of the quality metric does not correspond to the sum of the respective tunnel sizes associated with the respective ones of the plurality of tunnels, the operations further comprise:

determining a second plurality of candidate paths to carry the respective traffic for the plurality of tunnels, the second plurality of candidate paths being determined based on a second ordering of the plurality of tunnels different from the first ordering of the plurality of tunnels;

determining a second value of the quality metric representing a second aggregate tunnel bandwidth carried by the second plurality of candidate paths; and

determining the first routing information to describe the second plurality of candidate paths when the second value of the quality metric does not correspond to the sum of the respective tunnel sizes associated with the respective ones of the plurality of tunnels and the second value of the quality metric exceeds the first value of the quality metric.

12. The tangible machine readable storage medium of claim 10, wherein to determine the first plurality of candidate paths, the operations further comprise:

determining whether a first candidate path capable of supporting a first tunnel size associated with a first one of the plurality of tunnels is available in the network; and

in response to determining the first candidate path is available;

setting a routed bandwidth value for the first one of the plurality of tunnels equal to the first tunnel size; and

decreasing available link capacities of a first set of network links included in the first candidate path by the first tunnel size.

13. The tangible machine readable storage medium of claim 12, wherein the operations further comprise, in response to determining that the first candidate path is not available:

determining whether a second candidate path capable of supporting a portion of the first tunnel size associated with the first one of the plurality of tunnels is available in the network; and

in response to determining the second candidate path is available;

setting the routed bandwidth value for the first one of the plurality of tunnels equal to the portion of the first tunnel size; and

decreasing available link capacities of a second set of network links included in the second candidate path by the portion of the first tunnel size.

14. The tangible machine readable storage medium of claim 13, wherein the operations further comprise increasing the first value of the quality metric by the routed bandwidth value for the first one of the plurality of tunnels to determine the first value of the quality metric.

15. An apparatus to reroute tunnel traffic in a network, the apparatus comprising:

a memory having machine readable instructions stored thereon; and

a processor to execute the machine readable instructions to perform operations comprising;

in response to detecting an event associated with routing first traffic in a network, determining a plurality of paths to carry respective traffic for a plurality of tunnels between pairs of routers in the network, the plurality of paths being determined based on a quality metric characterizing an aggregate tunnel bandwidth to be carried by the plurality of paths for the plurality of tunnels; and

sending first routing information describing the plurality of paths to the routers in the network to cause the routers to route the respective traffic for the plurality of tunnels using the plurality of paths, at least some of the first routing information to replace second routing information previously determined at a first one of the routers in response to the event associated with routing the first traffic.

16. The apparatus of claim 0, wherein to determine the plurality of paths, the operations further comprise:

determining a first plurality of candidate paths to carry the respective traffic for the plurality of tunnels, respective ones of the plurality of tunnels associated with respective tunnel sizes;

determining a first value of the quality metric representing a first aggregate tunnel bandwidth carried by the first plurality of candidate paths; and

determining the first routing information to describe the first plurality of candidate paths when the first value of the quality metric corresponds to a sum of the respective tunnel sizes associated with the respective ones of the plurality of tunnels.

17. The apparatus of claim 16, wherein the first plurality of candidate paths is determined based on a first ordering of the plurality of tunnels, and when the first value of the quality metric does not correspond to the sum of the respective tunnel sizes associated with the respective ones of the plurality of tunnels, the operations further comprise:

determining a second plurality of candidate paths to carry the respective traffic for the plurality of tunnels, the second plurality of candidate paths being determined based on a second ordering of the plurality of tunnels different from the first ordering of the plurality of tunnels;

determining a second value of the quality metric representing a second aggregate tunnel bandwidth carried by the second plurality of candidate paths; and

determining the first routing information to describe the second plurality of candidate paths when the second value of the quality metric does not correspond to the sum of the respective tunnel sizes associated with the respective ones of the plurality of tunnels and the second value of the quality metric exceeds the first value of the quality metric.

18. The apparatus of claim 16, wherein determining the first plurality of candidate paths comprises:

determining whether a first candidate path capable of supporting a first tunnel size associated with a first one of the plurality of tunnels is available in the network; and

in response to determining the first candidate path is available;

setting a routed bandwidth value for the first one of the plurality of tunnels equal to the first tunnel size; and

decreasing available link capacities of a first set of network links included in the first candidate path by the first tunnel size.

19. The apparatus of claim 18, wherein the operations further comprise, in response to determining that the first candidate path is not available:

determining whether a second candidate path capable of supporting a portion of the first tunnel size associated with the first one of the plurality of tunnels is available in the network; and

in response to determining the second candidate path is available;

setting the routed bandwidth value for the first one of the plurality of tunnels equal to the portion of the first tunnel size; and

decreasing available link capacities of a second set of network links included in the second candidate path by the portion of the first tunnel size.

20. The apparatus of claim 0, wherein the operations further comprise increasing the first value of the quality metric by the routed bandwidth value for the first one of the plurality of tunnels to determine the first value of the quality metric.