METHOD AND APPARATUS FOR OUTAGE MEASUREMENT

• US 20070028147A1
• Filed: 09/25/2006
• Published: 02/01/2007
• Est. Priority Date: 07/30/2002
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Huang, Jiandong, Marathe, Madhav, Song, Sejun
• Granted Patent: US 7,523,355 B2
• Time in Patent Office: Days
• US Class Current: 714/43
• CPC Class Codes: H04L 41/0213 Standardised network management protocols, e.g. simple network management protocol [SNMP]
• CPC Class Codes: H04L 41/044 comprising hierarchical management structures
• CPC Class Codes: H04L 41/0604 using filtering, e.g. reduction of information by using priority, element types, position or time
• CPC Class Codes: H04L 41/064 involving time analysis
• CPC Class Codes: H04L 43/0811 by checking connectivity
• CPC Class Codes: H04L 43/10 Active monitoring, e.g. heartbeat, ping or trace-route
• CPC Class Codes: H04L 43/106 using time related information in packets, e.g. by adding timestamps

Abstract

An Outage Measurement System (OMS) monitors and measures outage data at a network processing device. The outage data can be stored in the device and transferred to a Network Management System (NMS) or other correlation tool for deriving outage information. The OMS automates the outage measurement process and is more accurate, efficient and cost effective than previous outage measurement systems.

Claims

1. An apparatus, comprising:

one or more processors;

a memory coupled to the processors comprising instructions executable by the processors, the processors operable when executing the instructions to;

monitor for outages occurring locally at a network device that is a single-point-of-failure for one or more remote endpoints that send communications from a first private network, through the network device, to a second network;

monitor for outages occurring remotely on first network links that connect the remote endpoints to the network device;

identify outage information according to the local and remote monitoring; and

send the outage information from the network device, over the second network to a remote system that is located outside the first private network and that monitors for outages located on remote links located in the second network.

2. The apparatus of claim 1, wherein the processors are located in the network device that is a single point-of-failure for messages originating in the first private network and addressed to other endpoints located in a publicly accessible network.

3. The apparatus of claim 2 wherein the processors are further operable to filter a plurality of failures associated with a same element into a single root cause notification that is included in the outage information.

4. The apparatus of claim 2 wherein the processors are further operable to generate both connectivity measurements as well as component operability measurements for inclusion within the outage information.

5. The apparatus of claim 2 wherein the processors are further operable to:

generate time stamp values according to a configured period;

store the periodically generated time stamp values in a local storage;

when recovering from a local crash, comparing a most recently stored time stamp value to a local current system time to determine an outage measurement for the local crash; and

include the outage measurement within the outage information.

6. The apparatus of claim 2 wherein the processors are further operable to perform the local and the remote outage monitoring according to configuration parameters sent from the remote system.

7. The apparatus of claim 6 wherein the received configuration parameters specify a pinging rate for pings sent from the network device.

8. The apparatus of claim 6 wherein the processors are further operable to identify neighboring devices using Cisco Discovery Protocol (CDP.)

9. An apparatus comprising:

one or more processors;

a memory coupled to the processors comprising instructions executable by the processors, the processors operable when executing the instructions to;

exchange communications with a remote network device that forwards messages generated by one or more remote endpoints located in a private network through the remote network device and to a publicly accessible network;

receive outage information generated by the remote network device, the received outage information corresponding to the remote network device and to private network links that connect the remote endpoints to the remote network device;

compare the received outage information to local outage information that corresponds to other network links for connecting the remote endpoints to the publicly accessible network, the local outage information generated independently from monitoring performed by the remote network device; and

identify failures on the private network links, the remote network device and the other network links according to the comparison such that outages affecting Internet accessibility for the remote endpoints are identified.

10. The apparatus of claim 9 wherein the remote network device is a single point of failure for the remote endpoints such that the processors that are located outside the private network cannot access the remote endpoints independently of the remote network device.

11. The apparatus of claim 9 wherein the processors are operable to calculate object availability using accumulated outage time values included in the received outage information.

12. The apparatus of claim 9 wherein the processors are operable to calculate a product of an accumulated outage time value that is included in the received outage information and an inverse of an accumulated number of failures that is included in the received outage information.

13. The apparatus of claim 9 wherein the remote network device is a router or a switch.

14. The apparatus of claim 9 wherein the processors are further operable to send a communication to control pinging by the remote network device for generating the outage information.

15. An apparatus, comprising:

one or more processors;

a memory coupled to the processors comprising instructions executable by the processors, the processors operable when executing the instructions to;

monitor for outages occurring locally at a network device that provides publicly accessible network access for one or more remote endpoints by transferring communications sent over a first private network by the remote endpoints to a second network;

monitor for outages occurring between the network device and the remote endpoints;

identify first outage information according to the local and remote monitoring; and

send the first outage information from the network device to a remote system that is located outside the first private network for combining with remotely-generated second outage information that identifies outages occurring between the network device and the publicly accessible network.

16. The apparatus of claim 15 wherein the first outage information, when combined with the second outage information, defines a completely monitored connection path extending from the remote endpoints, through the network device and to the publicly accessible network.

17. The apparatus of claim 15 wherein the processors are further operable to:

perform local monitoring by checking layer-2 link status for the network device; and

perform remote monitoring by checking layer-3 traffic flows between the remote endpoints and the network device.

18. The apparatus of claim 17 wherein the processors are further operable to:

analyze an input rate, an output rate, an input queue packet drop and an output queue packet drop to identify candidate endpoints for pinging; and

ping only the identified candidate endpoints to identify remote endpoints having outages;

wherein the identified candidate remote endpoints are a subset of the remote endpoints.

19. The apparatus of claim 15 wherein the processors are further operable to monitor a software process responsive to a configuration signal sent from the remote system.

20. The apparatus of claim 15 wherein the processors select objects for remote monitoring according to configuration signals sent from the remote system.