What is Network Function Virtualization (NFV)?

Introduction

“NFV stands for Network Function Virtualization. It is a way of running network functions such as routing, firewalling, and load balancing on virtual machines (VMs) instead of dedicated physical hardware. This means organizations do not need to buy expensive, specialized hardware for each function. Instead, they can use standard servers to host multiple network functions.”

Network Function Virtualization aims to reduce reliance on proprietary hardware appliances and increase the flexibility and scalability of network functions. In this blog, we will explain what NFV is, what its purpose is, what its architecture consists of, and what its benefits are.

Let’s begin by first understanding what NFV is.

What is Network Function Virtualization (NFV)?

Network Function Virtualization is the process of decoupling of network functions from proprietary hardware appliances and running them as software in virtual machines (VMs). This allows service providers to run their networks on standard servers instead of proprietary ones. The virtual machines use a hypervisor to run networking software and processes such as routing, firewall, and load balancing. These software-based network functions are called virtual network functions (VNFs).

Examples of network functions that can be virtualized include routers, firewalls, load balancers, VPNs, DPIs, and more.

Why NFV became important?

Before NFV, many network services depended on special hardware appliances. That model worked, but it also created problems. It increased hardware cost, slowed down deployment, and made scaling harder.

NFV changed that by letting companies run network functions in software. That gave service providers and large enterprises more flexibility. It also made it easier to launch new services without waiting for new hardware every time. ETSI’s NFV work was built around that need for more flexible and software-driven network operations.

History of Network Function Virtualization

The history of NFV can be traced back to the early 2010s when the telecommunications industry first realized the importance of virtualizing network functions. In 2012, a consortium of major telecom operators, which include AT&T, BT, and Deutsche Telekom, founded the NFV ISG (Industry Specification Group). They joined together in order to develop a framework for Network Function Virtualization. The first whitepaper published by ISG in 2012 showcased the concept as well as the benefits of NFV.

In the year 2013, the ETSI (European Telecommunications Standards Institute) launched its own NFV ISG. The first set of specifications was released in 2014. Since then, NFV has gained immense popularity among telecom operators implementing NFV solutions.

In 2015, it became a crucial component of 5G network architecture. By the end of 2019, it became a mainstream technology specifically in the telecom industry.

Purpose of Network Function Virtualization

The purpose of NFV is to improve the efficiency, agility, and innovation of network services. With Network Function Virtualization, service providers can:

• Reduce capital and operational expenses by using less physical hardware and more software-based solutions.
• Increase scalability and elasticity by provisioning and de-provisioning VNFs on demand, according to the changing network traffic and customer needs.
• Accelerate service delivery and deployment by launching new network services and applications faster and easier.
• Enhance service quality and performance by optimizing the use of network resources and improving fault tolerance and reliability.
• Foster innovation and differentiation by enabling new business models and revenue streams based on customized and value-added services.

How Network Function Virtualization Works?

In traditional networks, we are all aware of the fact that there are dedicated hardware appliances that are used to perform specific functions such as load balancing, routing, etc. With Network Function Virtualization, these network functions are virtualized. When we say virtualized, it simply means that they are decoupled from dedicated hardware and run as software applications on standard servers.

Now, the question that arises is how network functions are virtualized.

To make network functions virtualized, NFV makes use of virtualization techniques such as hypervisors or software-defined networking controllers in order to create VMs that can run network functions. These VMs are then further orchestrated and managed by a management and orchestration system. This ensures that the network functions are deployed, scaled, and maintained without wasting any time.

Now that we have a basic understanding of NFV. Let’s see its history.

Network Function Virtualization Architecture

The NFV architecture consists of three main components: the network functions virtualization infrastructure (NFVI), the virtual network functions (VNFs), and the NFV management and network orchestration (NFV-MANO). Below, we have explained each component in detail with an image.

NFVI (Network Functions Virtualization Infrastructure)

The NFVI is the physical layer that provides the compute, storage, and network resources for running VNFs. The NFVI can span across multiple locations, such as data centers, points of presence, or central offices. The NFVI also includes a hypervisor or a container platform that hosts the VNFs.

VNF (Virtual Network Functions)

The next component of Network Function Virtualization architecture is the VNF. The VNFs are the software implementations of network functions that run on top of the NFVI. The VNFs can perform various tasks such as routing, firewalling, load balancing, encryption, etc. The VNFs can be chained together to form complex network services. The VNFs can also communicate with each other and with external networks through interfaces.

MANO (Management and Network Orchestration)

The NFV-MANO is the functional block that manages and orchestrates the NFVI and the VNFs. The NFV-MANO consists of three sub-components:

• NFV orchestrator (NFVO)
• VNF Manager (VNFM)
• Virtual Infrastructure Manager (VIM)

Let’s understand each of these 3 components.

NFVO

The NFVO is responsible for coordinating the deployment and lifecycle management of network services across multiple NFVI domains. The NFVO also handles resource allocation, policy enforcement, fault management, and service catalog management.

VNFM

The VNFM is responsible for managing the lifecycle of individual VNFs. The VNFM handles tasks such as instantiation, configuration, scaling, updating, healing, and termination of VNFs. The VNFM also interacts with the VIM to request resources for VNFs.

VIM

The VIM is responsible for managing the resources and connectivity of the NFVI. The VIM handles tasks such as provisioning, monitoring, inventory management, and fault management of compute, storage, and network resources. The VIM also interacts with the VNFM to allocate resources for VNFs.

Applications of Network Function Virtualization

NFV is used in many real-world environments. Common examples include:

• Virtual firewalls: NFV allows firewall functions to be run as software, which makes the deployment of security more flexible and easier to expand.

• Virtual Routers: Routing functions can be offered via virtual machines rather than dedicated hardware for routing.

• Virtual load balancers: NFV allows you to distribute traffic between servers effectively without the need for separate physical devices.

• Telecom core functions: Telecom companies use NFV to enable the virtualization of core network functions, such as the processing of packets and session management.

• 5G network function: The NFV supports 5G, enabling the faster deployment of scalable and virtualized network functions.

• Edge Services: NFV assists in running services closer to the users, improving the response speed, and decreasing latency.

• Service provider platforms: Service providers utilize the NFV platform to create flexible platforms that provide various network services over a shared infrastructure.

This is also why NFV still matters. It is not just an old networking idea. It remains useful in telecom and in cloud-driven environments where flexibility and orchestration are important.

Let’s discuss some of the benefits associated with NFV.

Benefits of Network Function Virtualization

There are many benefits of using Network Function Virtualization for network operations. Some of them are:

• Lower capital expenses: By using standard servers instead of specialized hardware, service providers can save money on equipment costs.
• Lower operational expenses: By using virtualization and automation, service providers can reduce labor costs and power consumption.
• Faster service delivery: By using software-based network functions, service providers can deploy new services and applications in minutes or hours instead of weeks or months.
• Higher scalability: By using dynamic resource allocation and orchestration, service providers can scale up or down the network functions as needed without affecting performance or availability.
• Higher flexibility: By using modular and interoperable network functions, service providers can mix and match different vendors and technologies to suit their needs.
• Higher innovation: By using open standards and APIs, service providers can leverage a wider ecosystem of developers and partners to create new solutions and services.

Key Challenges of Network Function Virtualization

NFV has benefits, but it also has challenges.

Common issues include:

• Orchestration Complexity: Coordinating multiple VNFs, policies, and automation layers can make deployment and control more challenging.

• Incorporating Existing Systems: NFV often needs to work alongside legacy infrastructure such as legacy OSS/BSS platforms which may slow deployment times.

• Performance Tuning: Tuning virtual functions requires careful tuning to meet latency, throughput, and jitter targets.

• Lifecycle Management: For successful VNF deployment, scaling, healing, and upgrades, it takes strong operational control to deploy, scale back, or upgrade them effectively. As deployments expand end-to-end visibility becomes harder to keep track of across sites and vendors.

• Moving from VNFs to Cloud-Native Models: This shift demands new tools, skills, and operating models.

This is another reason why modern NFV discussions now include MANO, containers, and Kubernetes. As the environment becomes more flexible, it also becomes more complex.

Common Problems You May Face While Deploying NFV

Some of the problems you might face while deploying NFV are:

• Topology Complexity: NFV can lead to complex network topologies which make it challenging to manage as well as troubleshoot issues. This also results in increased downtime and maintenance costs.

• VNF On boarding Issues: VNF may not integrate seamlessly. Sometimes, this will lead to compatibility issues and a rise in security vulnerabilities.

• Reduced Network Visibility: We all know that network activity can be less visible in a virtualized environment. This further makes it more difficult to detect as well as respond to security threats on time.

Denial-of-Service Exposure: DoS attacks on virtual networks or VNF public interfaces can drain network resources and disrupt service availability. Similarly, a botnet may infect an unsecured VM, causing a large amount of traffic to other VNFs.  and NFV. Let’s discuss it!

Difference Between SDN and NFV

Below, we have explained the basic difference between the two in a tabular form.

Frequently Asked Questions

Q1. What is network function virtualization?

NFV or Network Function Virtualization is defined as the architecture that “virtualizes” network functions into building blocks that can create as well as deliver communication services.

Q2. What is difference between SDN and NFV?

SDN and NFV are both network technologies that aim to increase efficiency and flexibility. SDN separates the control and data planes, while Network Function Virtualization virtualizes network functions on software.

Q3. What is NFV and VNF?

VNF stands for virtual network function, which is a software implementation of a network function that can run on any hardware platform. NFV stands for network function virtualization, which is an architecture that guides the management and orchestration of VNFs across different locations.

Q4. What is NFV in 5G?

NFV, or network function virtualization, is a framework that uses software and virtual machines to implement network features and services for 5G networks.

Q5. What is an example of a NFV? 

A common example of NFV is a virtual firewall, where firewall functions run on virtual machines instead of dedicated hardware.

Conclusion

Network function virtualization started as a way to move network functions from hardware into software. That is still the base idea. But today, NFV also connects with cloud-native networking, containerized functions, orchestration, and 5G-ready infrastructure.

In this blog post, we have explained what Network Function Virtualization (NFV) is and how it works. We have also discussed its different purposes, benefits, and architecture, along with its components. We have explained the basic difference between the SDN and NFV. Apart from all this, Network Function Virtualization is crucial and paving the way for emerging technologies such as cloud computing, edge computing, 5G, IoT, and more.

If you have any questions or comments, feel free to leave them in the comment below. Thanks for reading!