中文摘要：

为提高测量精度并减少所需资源，提出一种近似的测量流长度分布的方法．通过分析产生一个定长原始流的概率分布，并考虑流的重尾特性对其产生的影响，给出了近似测量流长度分布的测量模型．理论分析和实验结果均表明，该方法在使用抽样技术条件下，可以准确对流长度分布作出统计，满足实际测量需要．

英文摘要：

To improve the measurement accuracy while reducing the resource usage, an approximate method for measuring flow length distributions was developed. The probability distribution model of original flow for a sampled flow of fixed length was analyzed, the effects of heavy-tailed feature of flow were investigated, and a measuring model which approximately measured flow length distribution was given. Theoretical analysis and experiment results both indicate that the method can generate the statistics of the flow length distribution accurately under the condition of using packet sampling, which meet the demands of actual measurement.