The power of SDN to improve the estimation of the ISP traffic matrix through the flow spread concept

Traffic matrix estimation in communication network is a long standing problem for its intrinsic difficulty and potential benefit to a vast number of network optimization and management functions. We address the improvement of the traffic matrix estimation by means of selected traffic flow measurements, besides the easily obtained link load measurements. The key contribution of this paper is the definition and assessment of an effective criterion, based on the flow spread parameter, to identify the flows to be measured that reduce the estimation error most. It turns out that a small percentage of flows are enough to drive the estimation error an order of magnitude lower than the one obtained with the classical solution solely based on link load measurements. Our algorithm, referred to as flow spread-based algorithm (FSBA), is also able to distribute measurement tasks fairly among network nodes, taking into account the available forwarding tables space. We also show that FSBA outperforms the state-of-the-art similar approaches. A detailed discussion on how the observation of the desired flows can be performed is done as well, by addressing the SDN paradigm. This is in fact a rapidly growing concept that enables individual flow measurements, though for only a limited number of flows to be practical with current technology.