关键词: 分组抽样, 流大小, 分布估计, 网络测量

Abstract:

In order to improve the estimation accuracy of flow size distribution,several maximum likelihood estimate（MLE） algorithms using SYN flag information and TCP sequence numbers are compared.The results show that the algorithms using SYN flag and SEQ information in TCP flow,especially the algorithm using both SYN flag and SEQ sequence numbers,are more accurate than the simple sampling estimation.Then,a nonuniform grained estimation algorithm of flow size is proposed,which implements the estimation with fine-grained estimators for the flow with small size and coarse-grained ones for the flow with large size.Case study demonstrates that the proposed algorithm is applicable and greatly improves the estimation accuracy of large-size flow with less computation.

Key words: packet sampling, flow size, distribution estimation, network measurement