quicSDN: Transitioning from TCP to QUIC for southbound communication in software-defined networks

In Software-Defined Networks (SDNs), the control plane and data plane communicate for various purposes such as applying configurations and collecting statistical data. While various methods have been proposed to reduce the overhead and enhance the scalability of SDNs, the impact of the transport layer protocol used for southbound communication has not been investigated. Existing SDNs rely on Transmission Control Protocol (TCP) to enforce reliability. In this paper, we show that the use of TCP imposes a considerable overhead on southbound communication, identify the causes of this overhead, and demonstrate how replacing TCP with Quick UDP Internet Connection (QUIC) protocol can enhance the performance of this communication. We introduce the quicSDN architecture to enable southbound communication in SDNs via the QUIC protocol. We present a reference architecture based on the standard, most widely-used protocols by the SDN community and show how the controller and switch are revamped to facilitate this transition. We compare, both analytically and empirically, the performance of quicSDN versus the traditional SDN architecture and confirm the superior performance of quicSDN. Our empirical evaluations in different settings demonstrate that quicSDN lowers communication overhead and message delivery delay by up to 82% and 45%, respectively, compared to SDNs using TCP for their southbound communication.