A Conflict-Free Routing Tables Update Method for Persistent Multilink and Node Failures in SDN Architectures

The large-scale network management abilities of centralized architectures, such as Software-Defined Networking (SDN), are attracting increasing interest from major computer networking companies. In this architecture type, the nodes follow the rerouting rules predefined by the control plane in the controller. However, when a link or node failure becomes persistent over the time, the controller must recompute the routing and rerouting rules and update the relevant nodes to maintain an acceptable quality of service (QoS). In this study, we propose a conflict-free mechanism for updates of routing and rerouting tables of nodes by the controller. This mechanism works without disrupting the current traffic if both persistent multilink and node failures occur. We describe an efficient strategy for choosing the nodes to update and define an update scheme for these nodes. We show through the simulations of our updating scheme on various networks that our strategy improves QoS by reducing packet routing delays and the data loss rate in case of persistent multilink and node failures in the network. We also compare our results to those of several existing studies.