Network function virtualization

Network functions virtualization (NFV) is a network architecture concept that leverages IT virtualization technologies to virtualize entire classes of network node functions into building blocks that may connect, or chain together, to create and deliver communication services. NFV relies upon traditional server-virtualization techniques such as those used in enterprise IT. A virtualized network function, or VNF, is implemented within one or more virtual machines or containers running different software and processes, on top of commercial off the shelf (COTS) high-volume servers, switches and storage devices, or even cloud computing infrastructure, instead of having custom hardware appliances for each network function thereby avoiding vendor lock-in. For example, a virtual session border controller could be deployed to protect a network without the typical cost and complexity of obtaining and installing physical network protection units. Other examples of NFV include virtualized load balancers, firewalls, intrusion detection devices and WAN accelerators to name a few. The decoupling of the network function software from the customized hardware platform realizes a flexible network architecture that enables agile network management, fast new service roll outs with significant reduction in CAPEX and OPEX. Product development within the telecommunication industry has traditionally followed rigorous standards for stability, protocol adherence and quality, reflected by the use of the term carrier grade to designate equipment demonstrating this high reliability and performance factor. While this model worked well in the past, it inevitably led to long product cycles, a slow pace of development and reliance on proprietary or specific hardware, e.g., bespoke application-specific integrated circuits (ASICs). This development model resulted in significant delays when rolling out new services, posed complex interoperability challenges and significant increase in CAPEX/OPEX when scaling network systems & infrastructure and enhancing network service capabilities to meet increasing network load and performance demands.