PRoPHYS: Providing Resilient Path in Hybrid Software Defined Networks

The growing reliance on high-bandwidth, time-critical, and delay-sensitive technologies (such as video streaming, voice over IP, and virtual reality) leads to a dominance of delay-sensitive IP flows. Nowadays, a 50ms protection interval is considered tolerable by service providers [1] since most applications support the resulting loss with limited impact on the end-user's quality of experience (QoE). However, following the increase of required broadband speed per application [2], the amount of packets lost during those 50ms will also increase, leading to disruptions in the buffer playout process, and negatively impacting the QoE. It is therefore essential to enhance network resiliency techniques in order to combat network failures. To tackle this problem, we devised PRoPHYS – Providing Resilient Path in Hybrid SDN – which leverages the centralized SDN controller in hybrid networks (SDN alongside legacy L2/L3 equipment) to monitor traffic or network segments, and quickly detect failures or network disruptions, to reroute traffic. PRoPHYS features two strategies (one passive and one active) to detect network segment failures; and is designed for smooth integration with legacy routing protocols, e.g., OSPF. Our evaluation of PRoPHYS illustrates that it can decrease downtime by 50% during segment link failures, thus reducing drastically the number of packets lost, while minimizing the number of false positives.