Seamless route updates in software-defined networking via quality of service compliance verification

In software-defined networking (SDN), the control plane and the data plane are decoupled. This allows high flexibility by providing abstractions for network management applications and being directly programmable. However, reconfiguration and updates of a network are sometimes inevitable due to topology changes, maintenance, or failures. In the scenario, a current route $C$ and a set of possible new routes $\{N_i\}$, where one of the new routes is required to replace the current route, are given. There is a chance that a new route $N_i$ is longer than a different new route $N_j$, but $N_i$ is a more reliable one and it will update faster or perform better after the update in terms of quality of service (QoS) demands. Taking into account the random nature of the network functioning, the present authors supplement the recently proposed algorithm by Delaet et al. for route updates with a technique based on Markov chains (MCs). As such, an enhanced algorithm for complying QoS demands during route updates is proposed in a seamless fashion. First, an extension to the update algorithm of Delaet et al. that describes the transmission of packets through a chosen route and compares the update process for all possible alternative routes is suggested. Second, several methods for choosing a combination of preferred subparts of new routes, resulting in an optimal, in the sense of QoS compliance, new route is provided.