We define a network management system (NM system) as a methodology and a set of tools that help in performing network management. In this section we describe the set of desirable features of an NM system in the form of a network administrator’s wish list. At this point, we are not concerned with whether the items on this wish list are easy to provide, how much they cost or even if it is even possible to provide the features listed. The main objective of this section is to capture all that one could possibly want from a NM system.
A NM system should help in rectifying network faults. Many organisations provide a helpdesk where employees call if they experience any network problems. The helpdesk staff records the problem and take corrective action. This form of management is often called Reactive Network Management. In contrast, a NM system may autonomously monitor the network to detect faults. When faults are detected, the NM system records it and may either take corrective action on its own or inform the appropriate personnel who then decide what to do. This form of management is often called Proactive Network Management. Proactive Network Management is generally better since it minimises the impact on the users. Ideally, a network fault should be detected and rectified before users even become aware of it.