Lyapunov-based design of a distributed wardrop load-balancing algorithm with application to software-defined networking

This paper presents an original discrete-time, distributed, noncooperative load-balancing algorithm, based on mean field game theory, which does not require explicit communications. The algorithm is proven to converge to an arbitrarily small neighborhood of a specific equilibrium among the loads of the providers, known as Wardrop equilibrium. Thanks to its characteristics, the algorithm is suitable for the software-defined networking (SDN) scenario, where service requests coming from the network nodes, i.e., the switches, are managed by the so-called SDN controllers, playing the role of providers. The proposed approach is aimed at dynamically balancing the requests of the switches among the SDN controllers to avoid congestion. This paper also suggests the adoption of SDN Proxies to improve the scalability of the overall SDN paradigm and presents an implementation of the algorithm in a proof-of-concept SDN scenario, which shows the effectiveness of the proposed solution with respect to the current approaches.