Network Functions Virtualization (NFV) offers many advantages over dedicated network devices including potential reduction in costs for network and data center operators and increased revenue opportunities with the agility it affords. However, the agility potential also introduces more performance, reliability and security uncertainty with so many alternatives in the manner in which the infrastructure is designed. Holistic and continual validation across all the boundaries in a software-defined cloud stack is required for NFV to achieve successful deployments by operators.