Energy adaptation in multi-core software routers

We consider a new generation of Commercial-Off-The-Shelf (COTS) Software Routers (SRs), able to effectively exploit multi-core/CPU hardware platforms. This choice was mainly driven from the fact that SRs are one of the few platforms including power management features, and that can be easily customized. Our main objective is to evaluate and to model the impact of power saving mechanisms, generally included in today’s COTS processors, on the SR networking performance and behaviour. To this purpose, we separately characterize the roles of both hardware and software layers through a large set of internal and external experimental measurements, obtained with a heterogeneous set of hardware platforms and SR setups. Starting from this detailed measure analysis, we propose a simple model, able to represent the SR performance with a high accuracy level in terms of packet throughput and related power consumption. The proposed model is thought to estimate how SRs behave under different network conditions and power management configurations. In fact, the model has been effectively applied inside a “green optimization” policy, which aims at minimizing power consumption, while maintaining a certain SR performance target. Finally, in order to provide an experimental evaluation of the proposed ideas, we apply such power management policies to a new generation software router platform, and we test their performance under real traffic traces. Keywords—software routers, green networking, performance measurement.