High-throughput anycast routing and congestion-free reconfiguration for SDNs

In this work, we focus on designing high-throughput anycast mechanisms in a software Defined Network (SDN), as anycast routing serves as a fundamental building block for many services. Specifically, we investigate two main challenges for efficient implementation of a SDN-based anycast system: high throughput anycast routing (HTAR) and congestion-free anycast reconfiguration (CFAR). For the first challenge, we design an anycast routing (ARFU) algorithm, based on the fully polynomial time approximation scheme and the single-source unsplittable flow routing method. We prove that ARFU produces a route that can achieve a throughput at least 1/2(1+ξ) of the optimum, where ξ > 0 is an arbitrarily small constant. We then propose an anycast reconfiguration algorithm with transitive configurations, called ARTC, for congestion-free. This algorithm tries to find a routing reconfiguration procedure consisting of at most T ≥ 1 transitive configurations while meeting all the flow demands. When traffic demands can not be satisfied, ARTC maximizes the minimum throughput using one transitive configuration. Our simulations demonstrate high-efficiency of our algorithms.