European Telecommunications Standards Institute (ETSI), was the first major organization to release an NFV (Network Functions Virtualization) standard in October 2013. The ETSI ISG NFV is a specifications group that has set standards for NFV management and network orchestration (MANO) and network orchestration (NFV MANO). ETSI is also instrumental in collaborative projects like OPNFV.

What is Network Functions Virtualization (NFV)

Network Functions Virtualization (NFV) or Virtual Network Function (VNF) is used as a virtualized method to design, deploy, and manage networking services, Network functions that can be virtualized with NFV include Domain Name Service (DNS), Network Address Translation (NAT), firewalls, and caching. 

NFV uses

An NFV allows the user to interact with network functions at the server level. NFV uses virtualized networking components to support an infrastructure totally independent of hardware. The standard resources of computing, storage, and network functions can all be virtualized and placed on Commercial-Off-The-Shelf (COTS) hardware like x86 servers. Having virtualized resources means that VMs can be given portions of the resources available on the x86 server. That way, multiple VMs can run on a single server and scale to consume the remaining free resources, Within the data center and the outside networks, the data plane and control plane can also be virtualized with NFV. With NFV, functions like routing. load balancing and firewalls are packaged as virtual machines (VMs) on commodity hardware. Individual virtual network functions, or VNFS, are an essential component of NFV architecture.

If VNF running on a virtual machine requires more bandwidth, for example, the administrator can move the VM to another physical server or provision another virtual machine on the original server to handle part of the load. Having this flexibility allows an IT department to respond in a more agile manner to changing business goals and network service demands. NFV is an initiative to transfer the "Network Services" sector by virtualizing the network services by replacing the dedicated hardware with Virtual Machines. "NFV is to separate network functions from dedicated hardware devices"; to use Virtual Machines instead of physical routers, physical firewalls, and physical load balancers. 

For e.g. if we purchase a server that supports 1000s of customers, it might also support all the capacity we have but what will happen if we don't have any customers. we already paid for it. With NFV we can avoid all of that and pay for the things we need. NFV allows needs to instantiate these network services or functions on demand, according to the needs, at any given point of time, scaling them up and scaling them down. So we get a lot of flexibility. 

Network Functions Virtualization is very important to the movement towards abstracting physical resources, NFV is important because it allows you to take virtualized functions like routing and firewalling, and visualize them. Traditional firewalling devices and routers are more prone to failure than virtualized versions. With Network Functions Virtualization you can deploy functions in the form of virtual machines on a range of hardware. This gives you the opportunity to change how your network is structured. 

Network Functions Virtualization also has some advantages in terms of disaster recovery. If a natural disaster or system failure affects your network then physical devices cannot escape being affected. However, a virtual device can be moved to another location or data center so that you can obtain normal operation much faster. 

Challenges Associated with NFV 

Challenges related to NFV are in three components of the technology: the NFV manager (NFVM), VNFS, and the NFV infrastructure. The Lean NFV has attempted to solve these problems by developing a new approach to NFV architecture. One reason there is complexity in the components of NFV technology is that there have been multiple organizations trying to standardize them.

Benefits of Network Function Virtualization 

The NFV concept was originally presented by a group of network service providers at the SDN and OpenFlow World Congress in October 2012. 

Network Functions Virtualization
Fig. Benefits of Network Functions Virtualization

If a service provider's customer requests a new function, for example, NFV enables the service provider to more easily add that service in the form of a virtual machine without upgrading or buying new hardware on the customer end. Basic NFV benefits also include reduced power consumption and increased physical space, since NFV eliminates most traditional hardware appliances. NFV can then help reduce both operational and capital expenditures. 

NFV gives providers the flexibility to run VNFS across different servers or move them around as needed when demand changes. For example, if a customer requests a new network function, they can spin up a new VM to handle that request. If the function is no longer needed, the VM can be decommissioned. This can also be a low-risk way to test the value of potential new service. 

Network operators who virtualize their network can save money, shorten the time-to-market for new or updated products, and better scale and adjust resources available to applications and services. Other benefits include: 

Less Vendor Lock-in

Running VNFS on COTS hardware, means organizations aren't locked into proprietary, fixed-function boxes that take truck rolls and significant time and labor to deploy and configure.

Greater Resource Efficiency

A virtualized data center or other infrastructure is more efficient to operate because more can be done with less. Datacenter footprint, power consumption, and cooling requirements can all be reduced or kept the same, but with increased workload capacity. This is possible because a single server can run multiple VNFS at once, so not as many servers are needed to do the same amount of work. When network demand changes, an organization can update its infrastructure through software instead of doing another truck roll. The instances where an organization needs to physically update its network and data centers are significantly reduced. 

Flexibility

Organizations have a sharpness for changing business requirements and new market opportunities. In simple terms, the time-to-market period is shortened because the network infrastructure can be changed to adequately support the organization's new products. A network that has gone through NFV is also able to adjust quickly and easily to changes in resource demand as traffic coming to the data center increases or decreases. Scaling up and down in the number of VMs and the resources provided to them can be done automatically through SDN software.