Abstract: “Network monitoring and measurement have become more and more important in a modern complicated network. In the past, administrators might only monitor a few network devices or less than a hundred computers. The network bandwidth may be just 10 or 100 Mbps; however, now administrators have to deal with not only higher speed wired network (more than 10 Gbps and ATM (Asynchronous Transfer Mode) network) but also wireless networks. Network administrators are constantly striving to maintain smooth operation of their networks. Network monitoring is a set of mechanisms that allows network administrators to know instantaneous state and long-term trends of a complex computer network. This paper provides the readers with an overview of the current network monitoring approaches, their architectures, features and properties. In addition, it presents a comparison between those approaches.”

Keywords: Network monitoring, traffic duplication, packet capture, deep packet inspection, flow observation.