What is NMS ?

Network Management System

NMS is responsible for the monitoring,alerting and reporting for the global network infrastructure.To understand network management system, we need to understand wgar exactly is network management ?In simpler terms network management means monitoring network activity using protocol analyzer.To eleborate the defination - network management is a service that employs a variety of tools, applications, and devices to assist human network managers in monitoring and maintaining nodes.

Network Management Architecture

Most network management architectures use the same basic structure and set of relationships. End stations (managed devices), such as computer systems and other network devices, run software that enables them to send alerts when they recognize problems (for example, when one or more user-determined thresholds are exceeded). Upon receiving these alerts, management entities are programmed to react by executing one, several, or a group of actions, including operator notification, event logging, system shutdown, and automatic attempts at system repair. Management entities also can poll end stations to check the values of certain variables. Polling can be automatic or user-initiated, but agents in the managed devices respond to all polls. Agents are software modules that first compile information about the managed devices in which they reside, then store this information in a management database, and finally provide it (proactively or reactively) to management entities within network management systems (NMSs) via a network management protocol. Well-known network management protocols include the Simple Network Management Protocol (SNMP) and Common Management Information Protocol (CMIP). Management proxies are entities that provide management information on behalf of other entities.

Network Management Model
Network management model is the primary means for understanding the major functions of network management systems.The standard network management model consists of five conecptual areas. They are
1) Performance Management
2) Configuration Management
3) Accounting Management
4) Fault Management
5) Security Management

Courtsey - cisco.com - http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/