Network functions virtualization (NFV) is significantly influencing the world of networking and changing how networks are designed, deployed, and managed. NFV gives network service providers freedom of choice and allows separating the networking software from the hardware. This decoupling brings advantages such as cost savings in deploying and operating the network, rapid on-demand provisioning of new network functions, increased efficiency, and agile network scalability. These advantages open the door for new business opportunities, bring new services to market quicker and have been attracting tremendous interest from cloud and Internet service providers, mobile operators, and enterprise market segments.