A Centralized and Conflict-Free Routing Table Update Method through Triplets' Lists Vector in SDN Architectures

For a long time, the distributed management protocols have proven their efficiency in managing computers' networks; however, the recent success of centralized management architectures such as software-defined networking (SDN) to supervise large-scale network infrastructures such as the Cloud, is attracting increasing interest from major computer network companies. In this architecture type, the network switches and routers just simply forward packets by following the flow table rules set by a controller, which owns the control plane of the network. Thus, faced with a failure, for example, the concerned nodes follow the rules provided by the same controller. With the IPFRR (IP Fast ReRoute) routing strategy known for its fast rerouting capabilities, these rules are computed and set up in the devices in advance. However, when a link or node failure becomes persistent over time, the controller must recompute the routing paths and update the nodes in order to keep an acceptable quality of service (QoS). In this paper, we propose a conflict-free mechanism for the routing and rerouting tables' updates of the nodes by the controller without disrupting the current traffic. We describe an efficient strategy of choosing the nodes to update, and we define an update scheme for these nodes. We demonstrate through the simulation of our update's scheme on different networks that our strategy improves QoS by reducing packet routing delays and the data loss rate in case of a persistent link failure in the network.