PROACTIVE TIMER-BASED LOCAL REPAIR PATH COMMUNICATION IN REACTIVE ROUTING NETWORKS

• US 20130250754A1
• Filed: 08/03/2012
• Published: 09/26/2013
• Est. Priority Date: 03/23/2012
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Vasseur, Jean-Philippe, Hui, Jonathan W.
• Granted Patent: US 9,232,458 B2
• Time in Patent Office: Days
• US Class Current: 370/225
• CPC Class Codes: H04L 45/32 Flooding denial of service attacks H04L63/1458
• CPC Class Codes: H04L 45/46 Cluster building
• CPC Class Codes: H04W 40/023 Limited or focused flooding to selected areas of a network
• CPC Class Codes: H04W 40/20 based on geographic position or location
• CPC Class Codes: H04W 40/28 for reactive routing

Abstract

In one embodiment, an intermediate device may determine a source route in use from a source to a destination in a reactive routing computer network, and may also determine a request to provide local repair for the source route for duration of a timer set by the source. In response to the request (e.g., and in response to a poor/failed connection), the device may discover a local repair path based on a limited-scope discovery, and maintains the local repair path for the source route until expiration of the timer.

Claims

1. A method, comprising:

determining a source route in use from a source to a destination in a reactive routing computer network;

determining a request to provide local repair for the source route for duration of a timer set by the source;

discovering, in response to the request, a local repair path based on a limited-scope discovery; and

maintaining the local repair path for the source route until expiration of the timer.

2. The method as in claim 1, further comprising:

monitoring connectivity to a next-hop node of the source route for the duration of the timer; and

discovering the local repair path in response to the connectivity being below a threshold.

3. The method as in claim 2, further comprising:

redirecting traffic using the source route onto the local repair path in response to the connectivity being below the threshold.

4. The method as in claim 3, further comprising:

notifying the source of the redirecting.

5. The method as in claim 4, wherein notifying the source of the redirecting comprises:

notifying the source of the redirecting only in response to one or more factors selected from a group consisting of;

a given path cost change;

a given path delay change; and

a given amount of traffic on the local repair path.

6. The method as in claim 1, wherein determining the request to provide local repair comprises:

detecting an explicit request within a path discovery probe message originated by the source.

7. The method as in claim 1, wherein determining the request to provide local repair comprises:

detecting an explicit indication within traffic sent using the source route.

8. The method as in claim 1, wherein discovering the local repair path comprises:

discovering the local repair path in further response to the timer being greater than a threshold length.

9. A method, comprising:

determining, by a source, a timer after the expiration of which discovered routes are flushed to cause new route discovery in a reactive routing computer network;

transmitting a route discovery probe into the computer network, the probe having an explicit indication of the timer;

selecting a discovered route based on the route discovery probe; and

transmitting traffic on the selected discovered route as a source route, the traffic carrying an explicit indication that the source route requests local repair for the source route for duration of the timer.

10. The method as in claim 9, further comprising:

receiving a notification that the traffic is being redirected onto a particular local repair path; and

determining whether to perform route rediscovery in response to the notification.

11. An apparatus, comprising:

one or more network interfaces to communicate within a reactive routing computer network;

a processor coupled to the network interfaces and adapted to execute one or more processes; and

a memory configured to store a process executable by the processor, the process when executed operable to;

determine a source route in use from a source to a destination in a reactive routing computer network;

determine a request to provide local repair for the source route for duration of a timer set by the source;

discover, in response to the request, a local repair path based on a limited-scope discovery; and

maintain the local repair path for the source route until expiration of the is timer.

12. The apparatus as in claim 11, wherein the process when executed is further operable to:

monitoring connectivity to a next-hop node of the source route for the duration of the timer; and

discover the local repair path in response to the connectivity being below a threshold.

13. The apparatus as in claim 12, wherein the process when executed is further operable to:

redirect traffic using the source route onto the local repair path in response to the connectivity being below the threshold.

14. The apparatus as in claim 13, wherein the process when executed is further operable to:

notify the source of the redirecting.

15. The apparatus as in claim 14, wherein the process when executed to notify the source of the redirecting is further operable to:

notify the source of the redirecting only in response to one or more factors selected from a group consisting of;

a given path cost change;

a given path delay change; and

a given amount of traffic on the local repair path.

16. The apparatus as in claim 11, wherein the process when executed to determine the request to provide local repair is further operable to:

detect an explicit request within a path discovery probe message originated by the source.

17. The apparatus as in claim 11, wherein the process when executed to determine the request to provide local repair is further operable to:

detect an explicit indication within traffic sent using the source route.

18. The apparatus as in claim 11, wherein the process when executed to discover the local repair path is further operable to:

discover the local repair path in further response to the timer being greater than a threshold length.

19. An apparatus, comprising:

one or more network interfaces to communicate within a reactive routing computer network;

a processor coupled to the network interfaces and adapted to execute one or more processes; and

a memory configured to store a process executable by the processor, the process when executed operable to;

determine, as a source, a timer after the expiration of which discovered routes are flushed to cause new route discovery in a reactive routing computer network;

transmit a route discovery probe into the computer network, the probe having an explicit indication of the timer;

select a discovered route based on the route discovery probe; and

transmit traffic on the selected discovered route as a source route, the is traffic carrying an explicit indication that the source route requests local repair for the source route for duration of the timer.

20. The apparatus as in claim 19, wherein the process when executed is further operable to:

receive a notification that the traffic is being redirected onto a particular local repair path; and

determine whether to perform route rediscovery in response to the notification.