FICIENCY MEASUREMENTS AND KCI REPORTING Migration of network functions from physical network elements to a virtualized cloud environment is a complex process and assessing whether the migrated functions are adhering to native cloud principles is a critical task for operators. Simply porting and virtualizing network functions may not optimize resource consumption and performance of the workload. There are known overheads that impact network functions in a virtualized cloud environment; these need to be assessed and quantified. They include Virtualization overhead Hypervisor overhead Overlay network virtual path overhead Furthermore, there are VNF design choices that impact VNF resource consumption and perfor- mance, including tradeoffs in the following: Use of nonuniform memory access (NUMA) Context switching between user space and kernel space Interrupt driven versus polling VNF efficiency can be defined as a measure of how efficiently a VNF processes offered load in production as compared to its performance in controlled lab tests. Assuming that utilization of each resource in production varies with the load, one way of computing this is to determine the ratio of offered load to VM resource utilization. If this ratio is the same as what has been benchmarked in the lab, efficiency would be considered 100%. If this ratio is smaller than the lab benchmark, effi- ciency is lower than 100% and considered degraded. If the ratio is higher than the lab benchmark, efficiency is higher than 100% and performing better than forecasted. The objective of computing the efficiency metric are multifold: Compare network function virtualization implementations across different suppliers Formulate recommendations for cost optimization Building the Network of the Future Forecast resource consumption under varying workload conditions Identify areas in cloud infrastructure and VNF design for performance optimizations Measuring VNF efficiency in production requires some prerequisites including Decomposition of VNF into workloads (data 