libVNF

Abstract

Network Function Virtualization (NFV) aims to reduce costs and increase flexibility of networks by moving functionality traditionally implemented in custom hardware into software packet processing applications, or virtual network functions (VNFs), running on commodity servers in a cloud. This paper describes the design and implementation of libVNF, a library to build high performance, horizontally scalable VNFs. Unlike existing frameworks for VNF development, our library (i) can be used for the development of L2/L3 middleboxes as well as VNFs that are transport layer endpoints; (ii) seamlessly supports multiple network stacks in the backend; and (iii) enables distributed implementation of VNFs via functions for distributed state and replica management. We have implemented a variety of VNFs using our library to demonstrate the expressiveness of our API. Our evaluation shows that building VNFs using libVNF can reduce the number of lines of code in the VNF by up to 50%. Further, optimizations in our library ensure that the performance of VNFs built with our library scales well with increasing number of CPU cores and distributed replicas.