Problem model for alarm correlation

• US 6,598,033 B2
• Filed: 07/14/1997
• Issued: 07/22/2003
• Est. Priority Date: 10/21/1996
• Status: Expired due to Term

• Current Assignee: Ciena Corporation
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Ross, Niall, White, Anthony Richard Phillip
• Primary Examiner(s): Davis, George B.
• Application Number:
  US08/892,433
• Publication Number:
  US 20010051937A1
• Time in Patent Office: 2,199 Days
• Field of Search: 706/46, 706/47, 706/45, 707/103
• US Class Current: 706/46
• CPC Class Codes: H04L 41/0233 Object-oriented techniques, for representation of network management data, e.g. common object request broker architecture [CORBA]
• 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 41/0856 by backing up or archiving configuration information
• CPC Class Codes: H04L 41/0893 Assignment of logical groups to network elements
• CPC Class Codes: H04L 41/0894 Policy-based network configuration management
• CPC Class Codes: H04M 3/36 Statistical metering, e.g. recording occasions when traffic exceeds capacity of trunks

Abstract

A method of processing data such as alarms from a communications network, the network comprising a plurality of network entities, having predetermined states of operation, the method comprising the step of creating an object (88) associated with a given state of one of the entities, such as a fault state. The object comprises knowledge based reasoning capability (89) such as rules for determining whether the entity is in the given state, and the method further comprises the steps of: passing data about the network, such as alarms and events, to the object; and inferring whether the entity is in the given fault state using the rules. This enables faster correlation of alarms and simpler development and maintenance of the rules.

Claims

1. An automated method of processing data from a communications network comprising a plurality of network entities, having predetermined states of operation, the method comprising the steps of:

creating a plurality of different objects each associated with different possible rival states of one of the entities, the objects comprising knowledge based reasoning capability for determining whether the entity is in a given one of the possible rival states;

passing data about the network to the objects;

and inferring whether the entity is in the given one of the possible rival states using the reasoning capability.

2. The method of claim 1 wherein the given state is a fault state.

3. The method of claim 2 wherein the data about the network comprises alarms and other events relating to abnormal or undesired operation of the network.

4. The method of claim 3 wherein the method further comprising the step of passing messages between the objects as part of the inference process.

5. The method of claim 1 wherein the object creation step is triggered by an event notified by the network, and the given state is a possible cause of the event.

6. The method of claim 1 wherein the object creation step is triggered by an event notified by the network, and the given state is a possible consequence of the event.

7. The method of claim 1 wherein the reasoning capability comprises rules grouped according to the class of messages they can process.

8. The method of claim 1 wherein the reasoning capability comprises rules for translating events notified by the network into a degradation of a service received or offered by the associated entity from or to other entities.

9. The method of claim 8, further comprising the step of passing such service degradation information to other objects associated with the same or the other entities.

10. The method of claim 1, wherein the inference steps for each object are carried out in parallel in threads sharing a common knowledge base.

11. The method of claim 1 wherein knowledge bases are built up for each part, the method of claim 1 is carried out in parallel on the separate parts, and the inference step is carried out using respective ones of the knowledge bases, and messages from one object in one knowledge base to a connected object in another, are passed transparently.

12. The method of claim 11 wherein a plurality of said objects are created, in one of the knowledge bases, and the inference steps for each of these objects are carried out in parallel, in threads wherein messages passed from these objects contain a reference to the thread in which they were processed.

13. A method of acquiring knowledge for the knowledge based reasoning capacity for the method of claim 1, comprising the step of creating rules for translating events notified by the network relating to the associated entity, into a degradation of a service offered by the associated entity to other entities.

14. An automated method of processing data from a communications network, comprising the step of:

applying a knowledge based reasoning capability to interpret the data, wherein the reasoning capability comprises object orientated hierarchy of rule bases, the hierarchy being arranged to have object orientated inheritance properties, such that the method further comprises the steps of;

determining whether a named rule is in one of the rule bases, and where it is not present, making available the same named rule from a rule base higher in the hierarchy;

and applying the named rule to the data.

15. The method of claim 14 wherein the data comprises events notified by the network, and the named rule is for inferring the cause of one of the events.

16. An automated method of processing data from a communications network comprising the steps of:

providing a knowledge based reasoning capability wherein the reasoning capability comprises one or more rulebases, comprising rules encoded directly in an object oriented language;

providing an object oriented compiler;

and applying said knowledge based reasoning capability to interpret the data by specialising selected classes of the compiler so extending its functionality that it compiles rules and standard code.

17. The method of claim 16 wherein the rules comprise rules for processing events notified by the network, the method comprising the step of applying the reasoning to determine the cause of the events.

18. The method of claim 16 wherein the compiler is a smalltalk compiler.