Building Hybrid Virtual Network Functions with eXpress Data Path

Network Function Virtualization (NFV) decouples network functions from dedicated, proprietary hardware into software Virtual Network Functions (VNFs) that can run on standard, commodity servers. One challenge of NFV is to provide high-throughput and low-latency network services. In this paper, we propose eVNF - a hybrid architecture to build and accelerate VNFs with eXpress Data Path (XDP). XDP is a Linux kernel framework that enables high-performance and programmable network processing. However, the programmability of XDP is limited to ensure kernel safety, thus causing difficulties in applying XDP to NFV. eVNF solves this problem by taking a hybrid approach: leave the simple but critical tasks inside the kernel with XDP, and let complex tasks be processed outside XDP, e.g., in user-space. With the hybrid architecture, eVNF allows building fast and flexible VNFs. We used eVNF to build three prototype VNFs: Firewall (eFW), Deep Packet Inspection (eDPI), and Load Balancer (eLB). We evaluated these VNFs in two service function chains using OpenStack. Our experiments showed that eVNF can significantly improve service throughput as well as reduce latency and CPU usage.