A survey of elephant flow detection in SDN

Elephant flows usually transfer significant amount of data in the network, which may tend to cause network congestion and impact the network performance. Therefore, the accurate, timely and low-cost elephant flow detection is crucial in efficient network management. Taking advantages of SDN (software defined network), the elephant flow detection appears a fresh developing change. This paper firstly describes the related management mechanisms in SDN. Then according to the detecting location, the elephant detection approaches are classified into two kinds: detection in switch and detection in endhost. In switches, the detection approaches are well studied and can be not only based on the Flow-Statistics threshold but also based on flow characteristics. In end-hosts, the detection approaches are mainly based on the Flow-Statistics threshold and often collecting flow-statistics through monitoring socket buffer or hypervisor. Finally, the paper makes a performance comparison and puts forward several points of future prediction in terms of the elephant flow detection taking the deepening development of SDN into account.