|M.Sc Student||Itamar Cohen|
|Subject||T-Plots: A Novel Approach to Network Design|
|Department||Department of Electrical Engineering||Supervisor||Full Professor Keslassy Isaac|
|Full Thesis text|
It is accepted wisdom that changes in the traffic matrix entail capacity over-provisioning, but there is no simple measure of just how much over-provisioning can buy. In this thesis, we aim to provide the network designer with a simple view of the network robustness to traffic matrix changes. We first present the Traffic Load Distribution Plots, or T-Plots, a class of plots illustrating the percentage of traffic matrices that can be serviced as a function of the capacity over-provisioning. For instance, from a simple look at their T-Plots, network designers can guarantee that their network services all admissible traffic matrices, or 99% of permutation traffic matrices, or all traffic matrices with ingress/egress load at most half the maximum. We further show that unfortunately in the general case plotting T-Plots is #P-Complete, i.e. that it is impossible to plot a T-plot in a polynomial time by the noon tools. However, we show that T-Plots can sometimes be closely modeled as Gaussian, thus only using two values (mean and variance) to quantify the robustness of a capacity allocation to traffic matrix changes; and we utilize these Gaussian T-Plots to provide a more robust capacity allocation. Finally, we demonstrate the benefits from using T-Plots by showing results of extensive Monte Carlo simulations in real backbone network.