M.Sc Student | Itamar Cohen |
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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.}