Energy‐Aware Controller Placement With Delay Guarantees for In‐Band SDN
Tomofumi Kondo, Luis Guillen, Satoru Izumi, Toru Abe, Takuo Suganuma · International Journal of Network Management · 2026
ABSTRACT 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.