Implementing data center network energy management capabilities in NS3

In this paper, we present an enhanced and holistic energy model for the widely used Network Simulator, NS3. As computing becomes more energy efficient, data movement, and hence data center networks consume an increasing percentage of the total energy consumption and it is important to provide energy management capabilities in the network simulators. Our enhanced NS3 simulator supports the use of different sleep modes for each network port on a switch/router and endpoint, and backplane on switch/router in order to reduce the network energy consumption. It also supports two port level power management mechanisms - unidirectional (transmitter only) and bidirectional (transmitter and receiver). Moreover, the simulator supports local consolidation that consolidates traffic across multiple outgoing/incoming links into a node, and a global controller that monitors all links in the network via a SDN-like mechanism and helps make better local consolidation decisions. The implemented capabilities are illustrated by applying them to the popular fat-tree based data center network. It is shown that the local consolidation mechanism coupled with bidirection port-level energy management can reduce the network energy consumption substantially.