Switch sizing for energy-efficient datacenter networks

Saving power in datacenter networks has become a pressing issue. ElasticTree and CARPO fat-tree networks have recently been proposed to reduce power consumption by using sleep mode during the operation stage of the network. In this paper, we address the design stage where the right switch size is evaluated to maximize power saving during the expected operation of the network. Our findings reveal that deploying a large number of small switches is more power-efficient than a small number of large switches when the traffic demand is relatively moderate or when servers exchanging traffic are in close proximity. We also discuss the impact of sleep mode on performance such as packet delay and loss.