Conflict-Aware Network State Updates in SDN

Abstract

In SDN (Software-Defined Networks), applications are granted the ability to control and manage networks, such as routing, access control, and load balance, which is considered one of the most significant characters of SDN. However, these concurrent applications are lack of interactions when they operate on overlapping portions of the traffic and introduce a critical challenge of potentially conflicting flow rules (including match fields and actions). When their actions are dropping, forwarding, or diverting to the controller, these kinds of flow rule conflicts are inherent and arduous, and there exist no appropriate compositional methods of resolving them. Under the circumstances, the paper proposes a general model of abstract network states where different applications can own their different network views. When conflicting rules are detected, the model provides new network states for applications by composing original network states and conflicting rules. Therefore, applications do not need to handle underlying conflicting rules and just achieve the latest network states to install flow rules correctly.