Fixed-Period Packet Sampling and its Application to Flow Rate Estimation

We propose a packet sampling strategy called fixed-period sampling, which selects at most one packet in every fixed-length period. Under the fixed-period sampling, the number of flow-cache lookups during a unit of time or the number of entries in a flow cache is bounded by a constant, which is simply expressed by a few tuning parameters. As an application of the fixed-period sampling, we also focus on the flow-rate estimation from fixed-period sampled packet streams. In particular, we propose a simple estimator based solely on the sampling frequency overestimates flow rates of detected flows. We have conducted simulation experiments using two real traces to show basic characteristics of the fixed-period sampling for the comparison with the fixed-period sampling. We also show the accuracy of the proposed flow-rate estimator through simulations.