This document discusses Network Function Virtualization (NFV) and its relationship to OpenStack. It provides an overview of NFV and the ETSI NFV specifications. It describes how ETSI NFV defines the virtualization of network functions and services. It also discusses how OpenStack addresses some of the infrastructure requirements for NFV such as multi-hypervisor support, different virtualization models, and exposing network and resource functions. The document presents examples of how NFV would virtualize a media resource function and related descriptors. It concludes by discussing the relationship between ETSI NFV and OpenStack/OPNFV and their collaborative efforts.