XDQ: Enhancing XDP with Queuing and Packet Scheduling

Modern internet users expect seamless, uninterrupted communication when using real-time applications, even when sharing the network connection with devices that produce heavy traffic. This trend has pushed the demand for more sophisticated packet schedulers on routers. However, given the limited resources on these routers, it is increasingly important to reduce the overhead associated with these schedulers. This paper presents XDP Queuing (XDQ), our ongoing work on achieving faster packet scheduling on the Linux operating system, which is popular on networking equipment. Linux provides eXpress Data Path (XDP), a high-performance programmable network data path using the eBPF framework, which allows code to process packets early from the driver. While XDP has found numerous uses in the industry, such as Denial-of-Service attack mitigation, load-balancers, and intrusion prevention systems, it currently has no mechanism for queueing or reordering packets and cannot implement traffic scheduling policies. Our contribution, XDQ, is a programmable packet scheduling extension for the XDP framework. XDQ uses recently proposed schemes for programmable queues. It allows writing packet schedulers using eBPF while benefiting from the XDP fast data path.