Subject : Telecom Network Management

Topic : Network Management Tools and Applications

When a centralized NMS receives a trap or a notification, it is called receiving an event.

A single problem source may cause multiple symptom and each symptom is detected is reported as an independent event to the management system obviously we do not want to treat each event independently and act to resolve it. thus, it is important that the management system correlates all these events and isolates the root cause of the problem.

The techniques used for accomplishing this are called event correlation techniques. there are several correlation techniques used to isolate and localize fault in networks. All are based on

1. Detecting end filtering of events.

2. Correlating observed events to isolate and localize the fault either to logically or functionally.

3. Identifying the cause of the problem. in all three methods / cases, there is intelligence or reasoning behind these methods. the risk approaches to correlation techniques.

   a) Rule based reasonings.

   b) Model based reasonings.

   c) case based reasonings.

   d) code look.

   e) state transition graph model.

   f) finite state machine model.