What is Network Functions Virtualization (NFV)? Explanation by Wallarm

NFV Meaning: What is Network Functions Virtualization?

A broad range of network node function categories is used in the creation of a network’s architecture. Managing and taking care of these node functions become a tough task. With NFV, it can be way too sorted as dispersed node functions are combined into modular units. 

The NFV process decouples network functions and hardware utilizing virtualization.

Besides simplifying the node function handling, this decoupling process supports network architecture scalability across computing and communication services.

This concept's virtualization methods are no different from the conventional server-virtualization process. However, it does have distinct features. For instance, there is no need to have customized hardware appliances per network function, which is the case with traditional server virtualization.

Instead of VNF or virtualized network function, it used a VM or virtual machine. One or many VMs take care of the process and software development. The concept is common, and we have multiple NFV examples from the real world. For instance, session border controllers, WAN accelerators, virtualized load-balancers, and intrusion detection devices are based on NVF only.

Based on the requirements, administrators can easily deploy any of these in a network architecture and enjoy unmatched network protection and delivery.

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History Of NFV

Even since the time of hardware creation for the telecom sector began, the industry needed help to eliminate slow development, tedious product cycles, and heavy dependency on proprietary hardware. Keeping this in mind, a network function virtualization-dedicated organization conducted extensive research and released a detailed whitepaper in the year 2012.

The paper covered SDN and OpenFlow while explaining the concept of NFV in detail. This was the first encounter that the world had with this concept. Based upon the facts and figures the white paper presented, a functional body, ISG or Industry Specification Group, was formed. ISG remained functional under ETSI or European Telecommunications Standard Institute (ETSI).

The forming bodies of the ISG majority included a leading telecom representative within Europe. However, many global industry players were also a part of it. In the early days, the focus of ETSI ISG NFV remained on API, data model, testing, protocols, security, future developments, and many more.

As time passed, leading NFV vendors improved IT virtualization in order to ensure higher scalability for the hardware, network management is fully optimized, and network architecture’s performance is improved. In 2021, the body released the 5th version of the specifications. This version provided guidelines for new specifications, enhancements, and features.  

From its early publication till today, more than 100 publications have been published on NFV. As projects like OSM, OpenStack, and ONAP are developed using the guidelines of ETSI ISG NSV, NSV enjoyed wide acceptance. In the future also, many more innovations are bound to come.

How Does It Work?

As far as the functionality of NFV is concerned, the basic principle here is to replace the functions related to diverse hardware networking parts and take them to VMs. This way, specific software looks after the firewall security routing and load-balancing tasks, which were originally handled by hardware tools.

An SDN or hypervisor is used to control and configure the concerned components. A network engineer can automate the process of virtualization and manage these aspects as per the need of the hour.

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NFV Architecture

As one tries to understand the functionality of NFV, it’s important to get familiar with NFV’s architecture. It may seem too complex for beginners, as too many components are involved. As per ETSI, the governing authority for NFV, mainly seven components form NFV.

• Virtualized network functions (VNF)

VNFs are specifically designed software applications with the purpose of supplying network functions. IP configuration, file sharing, and directory services are some of the key offerings of VNF for an NFV architecture.

• VNF Manager

As the name suggests, VNF Manager manages VNFs. It is recommended by experts for end-to-end lifecycle, if more than one VNF is used in an NFV ecosystem.

• Element Management (EM)

The key purpose of EM is to streamline the usage of VNF and manage their performance, faults, configuration, and security.

• NFV Infrastructure or NFVI

VFVs operate within NFVI and are made up of physical as well as virtual resources. It also comprises a virtualization layer.

• NFV Orchestrator

It takes care of the creation, management, and termination of VNF’s network services. Besides this, orchestrator also looks after the resources meant for networking, memory, and computation of NFVIs.

• Operation Support System/Business Support System

Commonly known as OSS/BSS, this component is related to the operator. The OSS part is responsible for the operator’s configuration, fault detection/correction, networking, and service management. BSS is concerned about managing the order, product, and customs of an operator.

• Virtualized Infrastructure Manager or VIM

VIM manages everything related to NFVI. Generally, it concerns the computing, storage space, and networking-specific resources of NFVI.

Why is NFV Important?

In the present era of virtual resources, NFV is a way to get rid of the limitation of physical hardware and expand the usability of networking components. With the help of NFV, organizations can easily virtualize load-balancing, firewall security, and routing. Not only is virtualization done, but all these components are practically visualized, providing more insights.

The continual service delivery was hard to attain with conventional hardware networking components as they have a high failure tendency. Your router or firewalling hardware will go down anytime, and fixing might take ages. 

This problem is easily fixed with NFV as the key networking functions are virtually-deployed and can be moved to a wide range of hardware. So, if one hardware fails, you can switch to another working hardware without any downtime. This way, the networking structure remains functional all the time.

Virtualization of networking components gives them much higher flexibility through network functions, making it important. Anyone can move them, automatically restart them, and scale them according to the need of the hour. This way, network infrastructure becomes highly pliable, which is not possible with physical networking components.

When disaster recovery is concerned, NFV is also important. With physical networking components, disaster recovery is very tedious because physical networking components will be heavily impacted in case of any failure. One vulnerability will impact the entire infrastructure.  

With NFV, networking components are moved to virtual space. In case of any failure or disaster, it’s easy to move them from one place to another without any major effort.  

All in all, NFV is important as it makes your networking components functional all the time, strong enough to bear any disaster, and so flexible that they can be modified instantly.

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Benefits Of NFV

The way NFV fills the caveats of traditional hardware management is laudable. As traditional hardware networks are sparsely spread and hard to manage, switching to NFV is ideal as it reduces effort and time.  

The conventional hardware management procedure is way too pocket-heavy, as the concerned organizations have to procure certain tools and devices. Also, they need more workforce to look after linked devices and software configuration and networking.  

As NFV virtualizes everything, there is no need to invest in hardware & human resources for architecting and managing the network. It permits VNFs to operate over a single generic server that the hypervisor manages. This process of management is less extensive and more productive. 

Because it is excessively easy to configure and maintain a virtualized network, organizations don’t have to rely on networking experts, who are highly-paid talents.

Scalability is easy to achieve with NFV as it’s easy to modify network functionality easily. Any time, organizations can add or delete functionalities without changing much of configurations.

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NFV Challenges 

Even though NFV is highly flexible, makes network architecture scalability easy to achieve, and reduces overheads, it’s not a flawless approach. It comes with significant risks and challenges. If you want to make the most of this concept, you need to learn about these challenges and make a way to fix them.

Let's get familiar with the challenges of NFV.

• Ineffective physical security controls

As network infrastructure is fully virtualized and moves to the cloud, they become prone to cyber threats and vulnerabilities. With each new case, your virtual network will have an expanded attack surface. It takes a lot of effort to keep the network protected.

• Expanded malware reach

As virtual network components are closely linked, malware can travel from one component to another easily. At times, it becomes so hard for the AppSec team to figure out how deeper malware has gone. This also makes it very difficult to isolate malware.

• Less transparency in network traffic

With NFV, you need to use ultra-advanced security tools that can blur the network traffic transparency.

• Various security solutions

As NFV works on multiple security layers, it demands various security tools. This makes the entire process too complex, and different kinds of tools with diverse functionalities are used.

These are the most common challenges of using NFV, and an ideal NFV user can learn to deal with these challenges effectively.

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NFV vs SDN

SDN or Software Defined Networking and NFV are not dependent terms, but they are linked as they have some common traits to share. For instance, both of them use network abstraction and virtualization.  

However, they both act differently when it comes to abstracting resources and decoupling the linked functions. In SDN, the concerned entities are the network architects responsible for forwarding functions decoupling so that network control is improved, programmability is achieved, and network automation is implemented.

NFV revolves around the virtualization of a network component. Despite having different concerned areas, they both can join hands to build a network that helps in software development, management, and operation.

SDN disintegrates control functions and network forwarding so that network control programmability is achieved.

NFV separates network functions from hardware so that network infrastructure is fully virtualized. SDN can operate over NFV but NFV doesn’t require SDN for functioning.

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NFV Applications

As a widely accepted approach, NFV has a wider scope and deeper implementation. Starting from mobile networks to virtual networks, this concept has been extensive.

Have a look at key areas where this concept is bringing the best possible outcomes:

• CDN or Content Delivery Networks
• Network monitoring
• IMS or IP multimedia subsystem
• Evolved Packet Core or EPC
• Load balance
• Network slicing
• WAF
• Load balancers
• SBC or Session border control or SBC
• Intrusion detection and NAT
• Software-defined branch and SD-WAN
• Virtual customer premises equipment or vCPE

NFV Implementation

The very first step to take toward NFV implementation is to develop and deploy VNFs or virtualized network functions. As you plan to develop VNFs, you need to understand that VNFs have to be developed in a sequence of the service chain.

Another highly optimized approach for NFV implementation is to use orchestration. With the help of this process, it’s possible to introduce and monitor VNF instances in the orchestration layer of the network. With these carrier-grade features, it’s easy for organizations to lower infrastructure maintenance, scale up security, and promote scalability.

However, you need to understand one fact: your orchestration layer of VNF management should be supported by the underlying technology. The type of VNF used shouldn’t impact it. 

As NFV is based heavily on virtualization, the virtualization layer technologies like container technologies and OpenStack can help you achieve seamless NFV implementation.

The next implementation suggestion is using MANO. As the MANO layer network function is highly diverse and varies according to the architecture, using the standard MANO option is the best approach.

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Conclusion

The above guide explained that NFV provides a new and inventive way to scale networking infrastructure. Its skillful implementation enables organizations to make the entire process seamless as it combines multiple node functions. Those who adopt this practice have a chance to move physical infrastructure to virtual space so that management becomes easy.  

However, this isn’t a flawless solution, as hardware complexities are replaced by the tediousness of virtual networks. Network traffic produces another challenge which is keeping cyber vulnerabilities at bay. In a time of surged network vulnerabilities, reducing the attack surface is hard.

The guide explained technologies that can reduce the risks linked with NFV. NFV is a great concept to adopt, but enough understanding is required to implement it correctly. We hope the guide provided a clear picture of the use and importance of NFV. Have any more queries? Drop them in a comment, and we will try to resolve them.