What Keeps Your Network up at Night?

The demand for ever-faster links and devices is competing with the need to make networks more energy-efficient. One energy-saving technique is shutting down dispensable parts of the network. In this work, we investigate the limits of link sleeping; i.e., turning off underutilized links. We show that turning transceivers on takes on the order of seconds, making them the bottleneck for fast network wake-up. We also present a power plane prototype designed to orchestrate link sleeping alongside standard routing protocols.