Energy evaluation of gigabit routers towards energy efficient network

Energy efficient routers are a promising step forward in the road-map towards energy efficient networking. In this paper, we use gigabit routers to measure and evaluate the impacts of green technologies in different scenarios. These programmable NetFPGA based routers come with the inbuilt feature of frequency scaling which can reduce the operational frequency of the board by half from 125MHz to 62.5MHz. Router power consumption is compared for standard and low frequency modes with different numbers of activated ports. Perpacket and per-byte energy costs in different cases with different packet sizes are measured and analyzed to evaluate the effects of frequency adjustment. Finally, a simple energy model for real traffic is proposed and evaluated. This paper reveals the internal power usage of a gigabit router at the granularity of packet, and header and payload byte level, and offers the reader a clear understanding of the potential power savings at different operational router frequencies, for different numbers of activated ports, various traffic loads and packet sizes, which would assist the green data center networks.