Network performance management is central to the long-term management of most networks. By gathering statistical data about the behaviour of managed network devices and traffic flows between them, trends in network performance can be predicted. There are various tools and protocols used for network performance management such as the simple network management protocol (SNMP) and Common Management Information Protocol (CMIP). This book discusses the more advanced netflow protocol which has the ability to characterize IP traffic and provide visibility for Network administrators. The book also explains how we can generate and archive netflow traces for analysis and research purposes. The book should be useful to researchers, IT professionals and Network Engineers who are interested in having more insights into how their computer networks are performing.