Existence, Identification and Stability of Elephant flows in IP Traffic

Traffic on the Internet today is routed on the shortest path to the destination. This is considered as the quickest path but if traffic congestion occurs on the route, packets are dropped and the traffic slows down due to the retransmission of the missing packets. If the network resources could be more evenly utilised, some congestions could be avoided and the problem with retransmissions could be reduced. In order to balance the load evenly over a network, the load variation has to be known and predictable. Other studies of IP traffic have shown that a small number of flows carry the main part of the network traffic, these flows are referred to as elephants. This property is studied in this report and the stability of these flows is examined. By aggregating with respect to the source and destination network of the traffic, individual flows are easily identified. This report also discusses how to identify the large flows during runtime in order to use their properties when calculating the stability for the future traffic demand. The traffic prediction is based on analysis of logged Internet traffic. The report concludes that the phenomenon with elephant and mice flows can be observed when aggregating traffic artificially by different lengths of their network prefixes. When calculating future stability of flows the network aggregation does not have a major impact