T. KondoLuis Andrés GuillénSatoru IzumiToru AbeTakuo Suganuma2026-03-222026-03-22202610.1002/nem.70036https://doi.org/10.1002/nem.70036https://andeanlibrary.org/handle/123456789/79289ABSTRACT Software‐defined networking (SDN) enables flexible, programmable networks, but in large deployments, poor controller placement can raise latency and energy use. This paper presents a practical in‐band SDN model and an optimization method that jointly accounts for control‐plane delay and device power consumption to place controllers and configure switches. We formulate the problem as a binary integer programming (BIP) that decides controller locations, which switches remain active, and port bit‐rates and routes. Experiments on a large WAN topology (Janos‐US) show the approach can cut total network energy by up to 15% while keeping control‐plane delays within required bounds, offering network operators a straightforward way to trade responsiveness for energy savings.enComputer scienceEnergy consumptionController (irrigation)Integer programmingLatency (audio)Port (circuit theory)Energy (signal processing)Computer networkPower consumptionDistributed computingarticle