METHODS AND APPARATUS TO DETECT AND RESTORE FLAPPING CIRCUITS IN IP AGGREGATION NETWORK ENVIRONMENTS

• US 20110149721A1
• Filed: 12/22/2009
• Published: 06/23/2011
• Est. Priority Date: 12/22/2009
• 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: Hossain, Monowar, Ilango, Thiru, Ferro, Robert, Figueroa, Luis, Bajpay, Paritosh, Yang, Chen-Yui, Lu, David
• Granted Patent: US 8,717,869 B2
• Time in Patent Office: Days
• US Class Current: 370/216
• CPC Class Codes: H04L 41/0213 Standardised network management protocols, e.g. simple network management protocol [SNMP]
• CPC Class Codes: H04L 41/0631 using root cause analysis; using analysis of correlation between notifications, alarms or events based on decision criteria, e.g. hierarchy, tree or time analysis
• CPC Class Codes: H04L 41/0654 using network fault recovery ring fault isolation or reconfiguration in loop networks without recovery actions by a network management system H04L12/437
• CPC Class Codes: H04L 41/5074 Handling of user complaints or trouble tickets
• CPC Class Codes: H04L 43/0817 by checking functioning
• CPC Class Codes: H04L 43/0823 Errors, e.g. transmission errors
• CPC Class Codes: H04L 43/0829 Packet loss
• CPC Class Codes: H04L 43/0852 Delays
• CPC Class Codes: H04L 43/087 Jitter

Abstract

Methods and apparatus to detect and restore flapping circuits in IP aggregation network environments are disclosed herein. An example method for use in maintaining a communication network includes retrieving information related to an operating state of a device associated with a network disturbance; determining whether the information related to the operating state of the device is indicative of a flapping condition; when the operating state information indicates that the flapping condition is present in the network, determining a cause of the flapping condition; when the cause of the flapping condition is a physical cause, selecting a first recovery procedure; and when the cause of the flapping condition is a logical cause, selecting a second recovery procedure different from the first recovery procedure.

Claims

1. A method for use in maintaining a communication network, comprising:

retrieving information related to an operating state of a device associated with a network disturbance;

determining whether the information related to the operating state of the device is indicative of a flapping condition;

when the operating state information indicates that the flapping condition is present in the network, determining a cause of the flapping condition;

when the cause of the flapping condition is a physical cause, selecting a first recovery procedure; and

when the cause of the flapping condition is a logical cause, selecting a second recovery procedure different from the first recovery procedure.

2. A method as defined in claim 1, wherein determining whether the information related to the operating state of the device is indicative of the flapping condition comprises calculating a rate at which the operating state of the device changed over a period of time including the network disturbance.

3. A method as defined in claim 2, wherein the operating state information is indicative of the flapping condition when the rate at which the operating state of the device changed over the period of time exceeds a threshold.

4. A method as defined in claim 1, wherein determining the cause of the flapping condition comprises analyzing utilization information associated with the device associated with the network disturbance.

5. A method as defined in claim 4, further comprising determining that the cause of the flapping condition is the logical cause when the utilization information indicates congestion on the device associated with the network disturbance.

6. A method as defined in claim 1, further comprising measuring a logical distance of a logical network circuit including the device associated with the network disturbance and using the logical distance of the logical network circuit to measure a characteristic of the logical network circuit over a period of time.

7. A method as defined in claim 6, further comprising determining that the cause of the flapping condition is the physical cause when the characteristic of the logical network circuit indicates a presence of a physical error along the logical network circuit.

8. A method as defined in claim 6, wherein the characteristic comprises at least one of packet jitter, packet latency, or packet loss.

9. A method as defined in claim 1, wherein the first recovery procedure includes a reconfiguration of the device, and wherein the second recovery procedure includes a rerouting of network communication from the device to another device.

10. A tangible machine accessible medium having instructions stored thereon that, when executed, cause a machine to:

retrieve information related to an operating state of a device associated with a network disturbance;

measure a logical distance of a logical network circuit including the device associated with the network disturbance;

use the logical distance of the logical network circuit to measure a characteristic of the logical network circuit over a period of time

determine whether the information related to the operating state of the device is indicative of a flapping condition by calculating a frequency at which the operating state of the device changed over a period of time including the network disturbance, wherein the operating state information is indicative of the flapping condition when the frequency at which the operating state of the device changed over the period of time exceeds a threshold;

when the operating state information indicates that the flapping condition is present in the network, determine a cause of the flapping condition;

when the cause of the flapping condition is a physical cause, select a first recovery procedure; and

when the cause of the flapping condition is a logical cause, select a second recovery procedure different from the first recovery procedure.

11. A tangible machine accessible medium as defined in claim 10 having instructions stored thereon that, when executed, cause a machine to determine the cause of the flapping condition by analyzing utilization information associated with the device associated with the network disturbance.

12. A tangible machine accessible medium as defined in claim 11 having instructions stored thereon that, when executed, cause a machine to determine that the cause of the flapping condition is the logical cause when the utilization information indicates congestion on the device associated with the network disturbance.

13. A tangible machine accessible medium as defined in claim 10 having instructions stored thereon that, when executed, cause a machine to determine that the cause of the flapping condition is the physical cause when the characteristic of the logical network circuit indicates a presence of a physical error along the logical network circuit.

14. A tangible machine accessible medium as defined in claim 10, wherein the first recovery procedure includes a reconfiguration of the device, and wherein the second recovery procedure includes a rerouting of network communication from the device to another device.

15. An apparatus in communication with an operational support system to receive a report of a network disturbance and to identify a device associated with the network disturbance, comprising:

a circuit analyzer to determine whether information related to an operating state of the device is indicative of a flapping circuit, wherein the operating state information includes a rate at which the device is switching operating states;

a root cause analyzer to determine whether the flapping circuit is caused by a physical condition by analyzing a characteristic associated with the device, the root cause analyzer is to determine whether the flapping circuit is caused by a logical condition by analyzing utilization information associated with the device; and

a selector to select a first recovery procedure when the root cause analyzer determines that the flapping circuit is likely caused by the physical condition, and the selector is to select a second recovery procedure different from the first recovery procedure when the root cause analyzer determines that the flapping circuit is likely caused by the logical condition.

16. An apparatus as defined in claim 15, wherein the first recovery procedure includes an interface reconfiguration of the device, and wherein the second recovery procedure includes a rerouting of network communications from the device to another device.

17. An apparatus as defined in claim 15, further comprising a logical path measurer to measure a logical distance of a logical network circuit including the device associated with the network disturbance.

18. An apparatus as defined in claim 17, wherein the logical distance of the logical network circuit including the device is used to determine the characteristic to be analyzed by the root cause analyzer.

19. An apparatus as defined in claim 15, the root cause analyzer to determine that the cause of the flapping condition is the logical cause when the utilization information indicates congestion on the device associated with the network disturbance.

20. An apparatus as defined in claim 15, the root cause analyzer to determine that the cause of the flapping condition is the physical cause when the characteristic of the logical network circuit indicates a presence of a physical error along the logical network circuit.