Network Management Resource Costs

The reliance on computer communications networks for business and commerce, education, entertainment and many other applications demands these resources are managed effectively. In this context, “management” refers to ensuring security and performance, recovering from faults and accounting for utilisation. Each of these activities requires knowledge of the network configuration, and information about the networked devices. It is on the basis of this knowledge that management decisions to change the configuration and network behaviour are taken. Hence the manager requires as full and accurate a set of information about the network under their control as it is possible to get. Typically, this information resides across the network and is transferred (to the network manager) to assist the network manager’s decision making. Therefore, network management creates network traffic and consumes network resources, as information is collected, transferred, and processed, and commands move to their required destinations. Because a typical computer network uses the same network facilities, data links, processors, network interfaces, switch, and router storage as ordinary user data, the management process must be efficient. Resources consumed by network management activity: bandwidth, processor time, and data storage space are not available to “real” network users and hence have a direct impact on the level of service experienced by users. Historically, this has meant network management designs being constrained to a greater or lesser extent by their resource consumption, and one development aim is often to deliver an effective network management service with as little resource consumption as possible. Indeed, proponents of particular network management paradigms, particularly the first version of the de facto standard Simple Network Management Protocol (SNMPv1) (Case, Fedor, Schoffstall, & Davin, 1990), made much of the minimal resource demands of their design. More recently, other network management proposals often use SNMPv1 as a benchmark for comparative resource consumption. It is therefore appropriate to consider the resource impacts of different network management paradigms to gauge likely effects on networks they manage. In this chapter, we identify the characteristics of various network management systems, describe how the ways in which these tools are used by a network manager generate work (traffic and processing loads) for the network, consider appropriate ways to measure their behaviour, and discuss performance data.