The difference between SDN and NFV - a simple guide - CodiLime

The difference between SDN and NFV - a simple guide

Konrad Budek

Reading time: 7 minutes

Network Function Virtualization (NFV) and Software Defined Networking (SDN) technologies are similar and can easily be mistaken for one another. However, is the difference between them significant from a business point of view?

This article explores:

  1. Why SDN and NFV technologies will become more popular
  2. What SDN is and how businesses can benefit from it
  3. What NFV is and what benefits come with it
  4. Why a combination of the two technologies is the best way to go

According to Cisco’s “The Zettabyte Era” report, annual global IP traffic will reach 3.3 zettabytes per year by 2021. Traffic from mobile and wireless devices will account for more than 63% of all internet traffic. Currently, more than 3.7 billion humans use the Internet and more than a half of searches are being done with mobile phones. Every minute users stream 64,444 hours of movies on Netflix, generate 460,000 tweets on Twitter and post 46,740 photos on Instagram. The Internet of Things is going to add massive amounts of traffic to the web. In fact, up to 87% of healthcare organizations are expected to adopt IoT technology by 2019.

The explosion of transfer usage and the devices connected with the global network will increase the need for technology to support it. Enabling a growing number of devices to effectively connect with the Internet means more sophisticated networks will have to be built out.

On top of all that, the popularity of cloud computing is growing, making global companies more dependent on reliable and fast internet traffic, compelling them to use NFV and SDN. But what are the benefits and the difference between these technologies?


SDN – novel approach to the networking

SDN is a novel approach to building networks, one that enables companies not only to transfer resources to the cloud, but also to emulate the entire network architecture. That provides numerous benefits:

  1. The administrator gains control over the whole architecture of the network with a single control panel
  2. It is easy to add new components to the network
  3. It is much easier to redesign network architecture without the need to rewire anything
  4. SDN technology provides redundancy and scalability at almost no additional cost
  5. The administrator can control the system’s security more easily than in traditional networks

SDN provides automation for networking technology, making the administrator’s work easier and faster. This cuts the dull and offline work with networks to a minimum, while maintaining the network’s functionality.


NFV – cutting costs intelligently

One brick in the foundation of NFV is network services providers’ need to optimize the cost of the machines they use to build networking solutions. By using virtual machines to emulate networking equipment, they gained the ability to use cheaper commodity hardware instead of costly specialized solutions. Instead of buying a specialized edge router, firewall and WAN Accelerator, the company could run all the functions within a computing cloud, as virtual machines emulating the functions of the hardware.

According to AT&T, NFV enables companies to reduce the cost of network maintenance by up to 15%.


SDN and NFV – one for all, all for one

SDN and NFV technologies are complementary yet independent.

  • SDN manages the whole network with a single centralized controller – It is easier to build an SDN solution with NFV controllers, but it is not necessary. Sometimes the functionality desired comes from the software itself – a separate firewall may be redundant when the security rules are managed by the controller
  • NFV is about emulating the hardware – it is possible to build a physical network with commodity software and wires, without building an actual SDN. Such a network is cheaper, but requires the same amount of work to manage and maintain.

Combining SDN and NFV technologies allows companies to maximize the benefits of virtualizing their network environment with virtual machines and by building even the most sophisticated networks within data centers.

  • It’s cheaper – there is no need to buy specialized hardware
  • It’s more secure – the administrator is able to establish the security rules for all components from a single control panel
  • It can be automated – there is no need to send a maintenance specialist to the physical location of a router or any other network component. Everything is done from one control panel. Specialists are sent only to attend to the most offline activities, like when the physical network is damaged.
  • The scalability is infinite – establishing a new network is only a question of how much computing power is available. Empowering a local network with cloud computing means scaling it to infinity.
  • The environment is flexible – adding or removing a component takes mere seconds. There is no need to buy a physical machine and have it delivered and wired into the network, nor later to have it removed. With less cash hung up in unused hardware, costs are ultimately reduced.



It is possible to use SDN technology without using NFV in a physical network or NFV components. But the technologies are complementary and using them separately limits the benefits a business will gain. Ultimately, to gain a competitive advantage and streamline operating costs, embracing SDN and NFV technologies will become necessary. After all, the chance to save up to 15% on network maintenance costs in nothing to sneeze at, right?


About the author