Dynamic Path Switching for Traffic Engineering in SD-WAN with eBPF

Software-Defined Wide Area Networking (SD-WAN) has emerged as a popular solution for today’s enterprise networks, where Traffic Engineering (TE) plays a crucial role in optimizing traffic distribution across different overlay tunnels. During network congestion, traditional SD-WAN approaches often switch traffic to backup Multiprotocol Label Switching (MPLS) tunnels with high economic costs. To address this issue, we introduce Dynamic Path Switching (DPS), a novel SD-WAN TE solution that leverages underlay path diversity within an Internet overlay tunnel to maintain high Quality of Service (QoS) while substantially reducing economic costs. DPS operates on a Virtual extensible Local Area Network (VXLAN) overlay and controls the 5-tuple flow ID in the outer encapsulation header of traffic flows at SD-WAN gateways, which enables Internet Service Providers (ISPs) to dynamically switch traffic flows across multiple underlay paths based on the hashing results of their flow IDs. Moreover, we leverage extended Berkeley Packet Filter (eBPF) to implement DPS with high efficiency. Our prototype implementation, evaluated on a real Internet testbed, demonstrates that DPS can provide 99.974% service availability for enterprise traffic while reducing economic costs by 64.26% compared to traditional MPLS-based SD-WAN TE solutions.