Chapter 11: Network Management Systems

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11.1 Introduction

Enterprise applications and mission-critical data that are essential to business operations rely on the availability and continued reliability of the corporate network. But the increasing use of wireless links and the Internet to extend the corporate network adds complexity to network management. While many companies prefer to retain total control of their network resources, others rely on computer vendors and carriers to find and correct problems on their networks or they depend on third-party service firms. Wherever these responsibilities ultimately reside, the tool set used for monitoring the status of the network and initiating corrective action is the NMS.

In addition to improving network availability (uptime) and service reliability, the purpose of an NMS is to centralize control of network components, reduce staff time for administrative tasks, and contain operational and maintenance costs. The NMS can effectively lower the cost and complexity of today’s networks by providing a set of integrated tools that allow IT staff to quickly isolate and diagnose network problems. The ability to analyze and resolve network problems from a central location is critical to the proper management of both network and personnel resources. The following are the minimum functional requirements of any NMS:

• Fault management. This function includes the detection, isolation, and correction of events that are responsible for abnormal network operation. Fault management provides the means to receive alarms, determine the cause of a network fault, isolate the fault, and implement corrective action.

• Configuration management. This function includes the setup, maintenance, and updating of network components. Configuration management also includes notification to network users of pending and completed configuration changes.

• Accounting management. This function includes the ability to track network usage to detect inefficiencies, abuse of network privileges, or unusual network activity—all of which are useful for planning network changes or growth.

• Performance management. This function includes the ability to recognize current or impending performance issues that can cause problems for network users. Activities include collecting and analyzing statistics to determine baseline network performance, as well as monitoring the system and conducting maintenance to ensure acceptable network performance.

• Security management. This function includes controlling and monitoring access to the network and associated network management information. This usually involves controlling passwords and user authorization mechanisms and collecting and analyzing security or access logs to reveal suspicious activity and track down its source.

Ideally, these and other functions should be available from the same network management interface, which treats the entire network as a single entity. In practice, however, NMSs vary in sophistication, forcing organizations to rely on different tools from different vendors to obtain all the functionality they need to properly manage their networks. Increasingly, corporate programmers are even applying their UNIX scriptwriting skills to enhance freely available open-source management utilities. Within a relatively short time, they can create management tools for the wireless environment that meet their needs simply and economically instead of having to work with limited APIs or petition a vendor for desired features, which may or may not show up in a subsequent release.

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