Toward energy-proportional Internet core networks: an energy-minimized routing and virtual topology design for Internet protocol layer

With the exponential growth of Internet traffic, the energy consumption issue of core networks is increasingly becoming critical. Today's core networks are highly underutilized most of the time because of the over-provisioning and redundancy dimensioning, which results in severe energy inefficiency. In previous work, many non-deterministic polynomial-time hard mathematics formulation models have been proposed to minimize the energy consumption of core networks. However, effective heuristics are needed to solve these models in medium/large-size networks. This work studies the energy-minimized routing and virtual topology design problem of the power-hungry Internet protocol IP layer in core networks, aiming to achieve an energy-proportional IP layer by exploiting the variation of traffic with hours to reconfigure virtual topology and reroute traffic. We formulate energy-minimized routing and virtual topology design as an Integer linear programming problem and propose a LR algorithm, a heuristic based on the Lagrangian relaxation, to solve this problem in a polynomial-time. The simulation results indicate that the LR algorithm outperforms the best previous algorithm and can achieve a near energy-proportional IP layer with significant power saving. Furthermore, a detailed analysis of simulation results is conducted, which suggests a design principle of network equipment to facilitate the power saving. Copyright © 2013 John Wiley & Sons, Ltd.