Nowadays, the network and communication technology are developing rapidly, while the network Quality of Service (QoS) are often not satisfied, because of the overburdened network and the overloaded routers and switches. Therefore, regular measurement and evaluation to the relative parameters and indexes are absolutely necessary. In this paper, the functional module of network measurement system and the commonly used network measurement instruments are introduced; active measurement, passive

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... urement and the application of these two measurements are presented; the advantages and disadvantages of these measurements are analyzed.