Energy proportionality of an enterprise network

Abstract

Energy efficiency is becoming increasingly important in the operation of networking infrastructure, especially in enterprise and data center networks. While strategies for lowering the energy consumption of network devices have been proposed, what is lacking is a comprehensive measurement study conducted across a large network (such as an enterprise), that monitors power usage as a function of traffic flowing through the network. We present a large power profile study that we conducted in an enterprise network, comprising of 90 live switches from various vendors. We first describe Urja, the system that we built, that collects required configurations from a wide variety of deployed switches and uses them to accurately predict the power consumed by individual devices and the network as a whole. Urja is vendor neutral, and relies on standard SNMP MIBs to gather the required configuration and traffic information. Further, based on available knobs in current devices, the analysis engine in Urja lists various configuration and rewiring changes that can be made to the devices in order to make the network more energy proportional. Urja has been deployed in an enterprise sub-network for about 4 months; through comprehensive analysis of the data collected over this period, we present various changes (in increasing order of cost and complexity) that network administrators can perform; in this segment of an enterprise network, we can save over 30% of the network energy through simple configuration and rewiring changes, and without any performance impact.