Network Functions Virtualization (NFV) :

 Network Functions Virtualization (NFV) :

NFV is a network architecture to accelerate service deployment for network operators and reduce cost by separating functions like firewall or encryption from dedicated hardware and moving them to virtual servers, collapsing various functions into a physical server.

·         It is a virtualized network service, such as routers, firewalls, and load balances, hosted on virtual machines.

·         Virtual machines have a hypervisor, called a virtual machine manager, by which multiple operating systems can share a single hardware processor.

 

Key Points

• NFV decouples network functions from the hardware, called virtual network functions (VNFs)
• VNFs run in virtual machines on commercial off-the-shelf (COTS) hardware like x86 servers.

·         The standard resources of computing, storage, and network functions can all be virtualized and placed on commercial off-the-shelf (COTS) hardware.

• NFV is used by SDN.
• NFV allows virtual machines (VMs) to handle changes in data center traffic.
• SDN and NFV are related but independent of each other.

·         NFV uses virtualized networking components that are totally independent of hardware.

 

Network functions virtualization include:

·         Pay-as-you-go: reduce costs because businesses pay only for what they need.

·         Fewer appliances: Because NFV runs on virtual machines

·         Scalability: virtual machines are faster and easier, and do not require purchasing additional hardware.

 

A hypervisor or software-defined networking controller allows network engineers to program all of the different segments of the virtual network.

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NFV architecture

An NFV architecture consists of three parts:

·         Centralized virtual network infrastructure: An NFV infrastructure may be based on either a container management platform or a hypervisor that abstracts the compute, storage, and network resources. 

·         Software applications: Software replaces the hardware components of traditional network architecture to deliver the different types of network functionality (virtualized network functions). 

·         Framework: A framework (often known as MANO – management, automation, and network orchestration) is needed to manage the infrastructure and provision network functionality.

Benefits

NFV promises a number of benefits to network operators, including:

• Reduce costs in purchasing network equipment via migration to software on standard servers
• Efficiencies in space, power, and cooling.
• Faster time to deployment.
• Flexibility – elastic scale up and scale down of capacity
• Access to a broad independent software community, including open source

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Risks of network function virtualization

• Physical security controls are not effective.
•  Malware is difficult to isolate and contain. 
• Network traffic is less transparent.
• Complex layers require multiple forms of security. 

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NFV Use Cases

NFV is applicable across a wide range of network functions, including fixed and mobile networks.  Some leading NFV applications include:

• Evolved Packet Core (EPC)
• Software-Defined Branch and SD-WAN
• IP Multi-Media Subsystem (IMS)
• Session Border Control (SBC)
• Video Servers
• Virtual Customer Premises Equipment (VCPE)
• Content Delivery Networks (CDN)
• Network Monitoring
• Network Slicing
• Service Delivery
• A variety of security functions – firewalls, intrusion detection and prevention systems, NAT, etc.

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