NFVi (network functions virtualization infrastructure) encompasses all of the networking hardware and software needed to support and connect virtual network functions in carrier networks.
NFVi resources can include operating systems, servers, hypervisors, virtual switches, virtual machines, virtual infrastructure managers and any other physical or virtual assets that enable network functions virtualization (NFV). Together, these elements form platforms for supporting NFV and hosting VNFs. NFVi can span multiple locations, in which case the network connecting those locations is also part of the overall NFVi.
The NFV architectural framework is a specification of the European Telecommunications Standards Institute (ETSI), which oversees its development.