Multipath load-adaptive routing: putting the emphasis on robustness and simplicity

We propose a routing and load-balancing approach with the primary goal of being robust to sudden topological changes and significant traffic matrix variations. The proposed method load-balances traffic over several routes in an adaptive way based on its local view of the load in the network. The focus is on robustness and simplicity, rather than optimality, and so it does not rely on a given traffic matrix, nor it is tuned to a specific topology. Instead, we aim to achieve a satisfactory routing under a wide range of traffic and topology scenarios based on each node's independent operation. The scheme avoids the instability risks of previous load-responsive routing schemes, it does not load the control plane with congestion-related signaling, and it can be implemented on top of existing routing protocols. In this paper, we present the proposed scheme, discuss how it aims to meet the objectives of robustness and load-responsiveness, and evaluate its performance under diverse traffic loads and topological changes with flow-level simulations.