Abstract
The flexibility and programmability offered by Software-Defined Networking (SDN) can lead to a higher frequency of network updates. During these updates, it becomes crucial to maintain consistency properties, such as preventing forwarding loops, black-holes, and ensuring congestion avoidance. However, preserving these properties in today’s SDN networks, especially datacenter networks, presents significant challenges due to their frequent or burst changes. Despite having varying levels of traffic priority, existing research has not adequately considered flow priority in the proposed frameworks for ensuring consistent network updates. This paper emphasizes the significance of incorporating flow priority when updating the data plane state of an SDN while preserving consistency properties. To address this issue, we propose a general architecture for continuous, consistent, and priority-based SDN updates. Our evaluation highlights the implications of neglecting flow priority when scheduling forwarding rule updates. Additionally, we report the consequences of disregarding flow priority on WAN and FatTree network topologies.