GreenSDN: Bringing energy efficiency to an SDN emulation environmentA significant number of green, energy-saving network protocols have been invented in recent years in response to demand for reducing the amount of energy consumed by network infrastructure. In this paper, we report on the difficulties we encountered when building an SDN environment that could emulate energy saving protocols operating at different layers of the network. We propose solutions, based on the Mininet environment and the POX Openflow controller, that emulate the effects of three different energy saving protocols. Our approach is validated by comparing energy savings obtained by activating these protocols in an emulated network topology inspired by the Brazilian Research Network.