s rendered traditional physical probes obsolete. The NFV approach for passive probing transforms the physical probe to a virtual probe (vProbe) network function that would be coresident with the service VNF of interest and use packet mirroring at the shared vSwitch. To realize the goal of eliminating the need for passive probe-based monitoring at various points in the network, because of inherent inefficiencies and cost penalties, the VNF should natively pro- vide enhanced instrumentation that allows passive measurements (e.g., session analysis) enabling a detailed view into the VF and network. Where a passive vProbe is deployed on a VNF interface, it would enable the following measurements: Detailed VNF transaction records (flow records, session records, transaction records, etc.) at configurable intervals Control-plane message stream processed by the VF User-plane stream (that is, configurable in a flexible manner-e.g., IPs, time interval, etc.) The above raw measurements can be further processed, aggregated, and analyzed to generate several important indicators. These indicators and relevant underlying data are exposed to the net- work operators to aid network planning, engineering, and troubleshooting services. Some of the common measurements and capabilities supported by a vProbe include Current capacity of the network element and capacity of the underlay network KPIs such as throughput, latency, errors Statistics describing the volume of transactions and their distribution, by protocol and direction Drill-down capability with visual access to troubleshoot root-causes of problems and fail- ures in the network Network Measurements Traditionally, data from passive probing have been extensively used to help Tier 3 or 4 support teams in troubleshooting and avoiding network problems and bottlenecks. As is the case with VNFs, orchestrated deployment of vProbes is facilitated through the use of heat orchestration templates. vProbes, once deployed, are controlled by the service orches- trator through the API and all