unctions The term virtual refers to functions or networks that have all the features and functions of hardware or network structures that they emulate, but their physical form is different. In the example of Virtual Network Functions, capabilities formerly found in hardware such as routers and switches are represented in software that has the same features and operates the same as hardware- based switches and routers. The network architecture can also be virtualized. This is done in Network Function Virtualization below. www.TechnicalPDF.com Network Function Virtualization-Architecture Network Function Virtualization (NFV) is an architecture in which network functions such as storage, routers, and switches are represented in software. These functions no longer need to be installed on dedicated, vendor-specific hardware. It's similar to server virtualization where multiple applications are installed as virtual machines on servers. However, instead of applications being virtualized, with NFV hardware devices (network nodes) are represented as software in servers. NFV specifies the way that these software functions fit together. Virtual Network Function-Transforming Hardware Nodes into Software Functions Virtual network function (VNF) refers to each piece of software in virtualized servers that represents a hardware function. These functions, some of which are listed below, can work together, are easily duplicated, and are generally installed on commodity hardware such as X86 and newer type servers with additional processing power. See Figure 4-1 for an example of VNFs in a single server. The equipment in which multiple VNFs are installed is referred to as a White Box. White Box with Virtual Network Functions (VNFs) Switch Router www.TechnicalPDF.com Firewall Virtual Network Security software Functions Load balancer Passive optical network software Open source operating system VNF Software on a commodity server with an Open Source operating system, e.g. is Linux, Junos etc. A proprietary operating system can also be