Evaluation of an end-to-end delay estimation in the case of multiple flows in SDN networks

Though SDN (Software Defined Network) provides the executive building blocks for programming data-plane appliances, controller decisions must be grounded in an accurate outlook on the network topology and performance. In this context, we focus on the possibility of providing accurate measurements for the end-to-end (E2E) delay in SDN networks. In practice, like many variable quantities, a good description of the E2E delay requires characterizing its first two moments, i.e., expectation and variance. We propose to estimate the E2E delay by making use only of measurements collected locally on each node of the network. We extend a procedure that has been proposed to estimate the E2E delay in the case of one flow to handle the case of multiple competing flows. We compare its accuracy using several scenarios, with different types of traffic following real traces, different topologies and bandwidth. Also, an analysis of the computational and networking costs of our solution is proposed.