Software-Defined Network Function Virtualization: A Survey

TLDR

Network function virtualization (NFV) proposes replacing costly proprietary appliances with software on commodity hardware, reducing capital and operational expenses while enabling agile traffic steering and joint optimization when integrated with SDN. This survey investigates the evolution of NFV within a software‑defined architecture, emphasizing service chaining as a key application. The survey outlines the software‑defined NFV architecture, traces its evolution from middleboxes, and discusses challenges, solutions, and future research directions across application domains. NFV enables flexible provisioning, deployment, and centralized management of virtual network functions, and the software‑defined architecture is increasingly adopted for applications such as service chaining.

Abstract

Diverse proprietary network appliances increase both the capital and operational expense of service providers, meanwhile causing problems of network ossification. Network function virtualization (NFV) is proposed to address these issues by implementing network functions as pure software on commodity and general hardware. NFV allows flexible provisioning, deployment, and centralized management of virtual network functions. Integrated with SDN, the software-defined NFV architecture further offers agile traffic steering and joint optimization of network functions and resources. This architecture benefits a wide range of applications (e.g., service chaining) and is becoming the dominant form of NFV. In this survey, we present a thorough investigation of the development of NFV under the software-defined NFV architecture, with an emphasis on service chaining as its application. We first introduce the software-defined NFV architecture as the state of the art of NFV and present relationships between NFV and SDN. Then, we provide a historic view of the involvement from middlebox to NFV. Finally, we introduce significant challenges and relevant solutions of NFV, and discuss its future research directions by different application domains.