 used. Figure 4-1 A White Box with network hardware abstracted in VNF software. White Box The term White Box denotes a server with multiple instances of virtual network functions (VNFs) within a single server. Each of the functions listed below were formerly housed in individual, proprietary, vendor-specific hardware www.TechnicalPDF.com "boxes." The NFV architecture enables these capabilities, previously implemented in various pieces of vendor-specific hardware, to exist with other network functions in a single open source commodity server. The advantage of a White Box is that functions within it can be more easily installed and duplicated than installing hardware and backing up each piece of hardware in the event of failure. Additionally, network functions can be added more quickly, a factor in increasing the speed of upgrading network functions. The following are examples of Virtual Network Functions, which can be virtualized as software within servers and White Boxes: Routers that route traffic between networks Switches that transmit traffic within a network Load balancers that balance traffic between multiple broadband circuits SO that no single circuit (path) is unduly congested Controllers that manage applications and send commands to devices Gateways that translate between networks that use different protocols Network Address Translation (NAT), which translates between external IP addresses and internal IP addresses for internal devices Security software in appliances (appliances are hardware dedicated to a single function) Firewalls that screen incoming traffic for viruses and other types of attacks The key advantages of installing network functions in software are flexibility, agility, and speed of implementation. Functions can be deployed and duplicated easily and quickly using computer commands in software. Instead of programming, purchasing, and managing distinct pieces of hardware, control software can be used to add network functions to the parts of networks where they are needed. www.TechnicalPDF.