ENERO: Efficient Real-Time Routing Optimization

Wide Area Networks (WAN) are a key infrastructure in today's society. During the last years, WANs have seen a considerable increase in network's traffic as well as in the number of network applications. To enable the deployment of emergent network applications (e.g., Vehicular networks, Internet of Things), existing Traffic Engineering (TE) solutions must be able to achieve high performance real-time network operation. In addition, TE solutions must be able to adapt to dynamic scenarios (e.g., changes in the traffic matrix or topology link failures). However, current TE technologies rely on hand-crafted heuristics or computationally expensive solvers, which are not suitable for highly dynamic TE scenarios. In this paper we propose Enero, an efficient real-time TE engine. Enero is based on a two-stage optimization process. In the first one, it leverages Deep Reinforcement Learning (DRL) to optimize the routing configuration by generating a long-term TE strategy. We integrated a Graph Neural Network (GNN) into the DRL agent to enable efficient TE on dynamic networks. In the second stage, Enero uses a Local Search algorithm to improve DRL's solution without adding computational overhead to the optimization process. Enero offers a lower bound in performance, enabling the network operator to know the worst-case performance of the DRL agent. We believe that the lower bound in performance will lighten the path of deploying DRL-based solutions in real-world network scenarios. The experimental results indicate that Enero is able to operate in real-world dynamic network topologies in 4.5 seconds on average for topologies up to 100 edges.