Network operators must be able to diagnose and troubleshoot problems as they arise in the network. When there are problems, they need to be able to get to the heart of them quickly and efficiently. They need to reliably determine its root cause and address it, fast. Every second of delay could be hundreds of annoyed customers or thousands of dollars of lost revenue as peers route their calls elsewhere, and perhaps don’t come back. As network operators leverage Network Functions Virtualization (NFV) and Software Defined Networking (SDN) to rapidly roll out new services, increase service flexibility, reduce capital and operational expenditures, and become more agile, Service Assurance (SA) has struggled to keep pace. Part of SA’s struggle stems from the challenge of maintaining continuous SIP session visibility both within a virtual infrastructure as well as across hybrid physical/virtual environments.