Side-Effects Causing Hidden Conflicts in Software-Defined Networks

Abstract

The Software-Defined Networking (SDN) architecture facilitates the flexible deployment of network functions by detaching them from network devices to a logically centralized point, the so-called SDN controller, and maintaining a common communication interface between them. While promoting innovation for each side, this architecture also induces a higher chance of conflicts between concurrent control applications compared to existing traditional networks. We have discovered a new type of anomalies that we call hidden conflicts. They appear to occur only due to side-effects of control application’s behaviour and to be independent of and distinct from the class of conflicts between rules present in the network devices. We analyse the SDN interaction primitives susceptible to such disruptions and present experiments supporting our analysis, the result of which indicates the necessity of the knowledge on the control mechanics in detecting hidden conflicts. We present a hidden conflict prediction approach that employs speculative provocation to determine the deployed applications’ behaviour. The observed behaviour can be leveraged to predict undesired network state. Evaluation of our prediction prototype suggests that prediction functions should be integrated into control applications.