Cloud Computing: Survey on Energy Efficiency <s> Scaling of Energy Consumption with Load in Wired Networks. <s> Most Ethernet interfaces available for deployment in switches and hosts today can operate in a variety of different low power modes. However, currently these modes have very limited usage models. They do not take advantage of periods of inactivity, when the links remain idle or under-utilized. In this study, we propose methods that allow for detection of such periods to obtain energy savings with little impact on loss or delay. We evaluate our methods on a wide range of real-time traffic traces collected at a high-speed backbone switch within our campus LAN. Our results show that Ethernet interfaces at both ends can be put in extremely low power modes anywhere from 40%-98% of the time observed. In addition, we found that approximately 37% of interfaces studied (on the same switch) can be put in low power modes simultaneously which opens the potential for further energy savings in the switching fabric within the switch. <s> BIB001 </s> Cloud Computing: Survey on Energy Efficiency <s> Scaling of Energy Consumption with Load in Wired Networks. <s> We present the design and evaluation of two forms of power management schemes that reduce the energy consumption of networks. The first is based on putting network components to sleep during idle times, reducing energy consumed in the absence of packets. The second is based on adapting the rate of network operation to the offered workload, reducing the energy consumed when actively processing packets. ::: ::: For real-world traffic workloads and topologies and using power constants drawn from existing network equipment, we show that even simple schemes for sleeping or rate-adaptation can offer substantial savings. For instance, our practical algorithms stand to halve energy consumption for lightly utilized networks (10-20%). We show that these savings approach the maximum achievable by any algorithms using the same power management primitives. Moreover this energy can be saved without noticeably increasing loss and with a small and controlled increase in latency (<10ms). Finally, we show that both sleeping and rate adaptation are valuable depending (primarily) on the power profile of network equipment and the utilization of the network itself. <s> BIB002
Initial attention has been focused on designing energy-aware network devices in which power consumption is manageable according to traffic load. Among them, sleeping and rate adaptation are two representative approaches. In BIB001 , the authors proposed taking advantage of the low-power modes of Ethernet interfaces and discussed the detection of inactive periods to obtain energy savings with slight impact on network performance. BIB002 then presented two network power management schemes: adapting the rate based on offered workload during packet processing and sleeping during idle times.