Characterization of high-rate large-sized flows

High-rate, large-sized (α) flows are of interest to providers for various reasons, e.g., they have the potential to degrade service quality for real-time flows, and users are sensitive to the throughput variance of these flows. In this paper, we present characteristics, such as size, duration, average rate, of α flows computed from NetFlow records collected over a 7-month period from 4 ESnet routers. Flows moving datasets as large as 811 GB and at rates as high as 5.7 Gbps were observed. Some source-destination pairs were found to repeatedly create α flows. An analysis of the rates of the 1596 repeated α flows created by one pair showed considerable variance, with minimum rate of 100 Mbps, maximum rate of 536 Mbps, and a coefficient of variation of 30%.