Kletzander, R. (2017):
A Testbed for Researching Conflicts in Software-Defined Networks
Software-Deined Networks (SDN) are said to have ushered in the software era of networking, enabling modular, dynamic network management by providing a platform for easy-to-develop applications running on a controller. Different applications, just like different devices in traditional networks, implement policies and wherever several policies coexist, there is a potential for conflict. Current research in the area of conflicts between applications primarily focuses on detection and resolution, but little research actually examines the conflicts themselves. In order to satisfy the necessary requirement of automatic detection and resolution of conflicts in SDNs, a better understanding of possible conflicts must be developed. A testbed is designed and implemented to closely examine conflicts between SDN applications and the consequences of these conflicts. Specifically, this involves examining the circumstances that lead two applications that function perfectly well individually, to create unpredictable results that break network policies when they are run concurrently. A network management scenario is constructed, yielding policies that are likely to conflict, and a parameter study is conducted to determine what parameters could affect conflicts between applications. The results of the parameter study are used as a basis for the design of the testbed. The causes and effects of occuring conflicts are analyzed, and possible conflict-specific solutions are suggested. The Findings show that the testbed enables systematic testing and analysis of different parameters that are likely to cause conflicts.