SDN and NFV: The future of networking

Swapna Bapat

Software Defined networking (SDN) and Network Functions Virtualisation (NFV) have become hot topics in the networking industry in the last few years. While both technologies are designed to allow data centers to be more agile and flexible in responding to changes in the business world, they are two distinct technologies and must not be used interchangeably.

SDN vs. NFV

SDN got its start on university campus networks. As researchers were experimenting with new protocols, they were frustrated by the need to change the software in the network devices each time they wanted to try a new approach. They came up with the idea of making the behaviour of the network devices programmable, and allowing them to be controlled by a central element which gave birth to SDN.

Meanwhile, web-based companies who were dissatisfied with the sluggish pace of innovation in traditional networking began investing in - SDN that soon showed promise in improving how data centers could be controlled.

While SDN was created by researchers and data centre architects, NFV was initially created by various large service providers that wanted to speed up deployment of new network services in order to advance their revenue and growth plans, and they found that hardware-based appliances limited their ability to achieve these goals. They looked to standard IT virtualization technologies and found NFV helped accelerate service innovation and provisioning.

Simply put, SDN is a new way to manipulate the network, and NFV as a new type of infrastructure to be manipulated. SDN is about controlling network hardware, whereas NFV is about taking what used to be specialized hardware and creating it in software on commodity servers.

What are the key differences?

There are key differences between SDN and NFV, but the confusion stems from four commonalities between the two: First, both have arisen from customer demand for more flexibility and interoperability, rather than the advent of a particular technology. The second is timing; the concepts emerged in quick succession. Thirdly, coexistence – they can and are used together. Finally, NFV and SDN are used in conjunction with a variety of other new technologies.

One of the key differences is that SDN separates the network’s control (brains) and forwarding (muscle) planes and provides a centralized view of the distributed network for more efficient orchestration and automation of network services.

SDN encompasses multiple kinds of network technologies designed to make the network more flexible and agile to support the virtualized server and storage infrastructure of the modern data center.

In contrast, NFV offers a new way to design, deploy and manage networking services.

NFV is designed to consolidate and deliver the networking components needed to support a fully virtualized infrastructure – including virtual servers, storage, and even other networks. Once the network functions are under the control of a hypervisor, the services that required dedicated hardware can be performed on standard x86 servers. These functions can be moved within networks on demand and scaled up and down as needed, without the delay and cost of installing new hardware devices.

In addition, NFV enables fast /low cost feature upgrades resulting in rapid innovation in service offerings (months or quarters instead of years or decades).

Priming businesses for growth

The NFV model allows for not only the use of powerful, low cost server hardware but also the ability for operators and enterprises to deploy and/or update services much more quickly and at far lower cost than what occurs in status quo operations. With NFV, the old model of taking weeks or months to upgrade dedicated hardware solutions across a geographically large network becomes a thing of the past. NFV allows for the transition of new systems architecture, enabling new network designs, increasing agility and flexibility.

Although NFV was originally conceived by large service providers, enterprise network operators who are moving some of their workloads to the cloud are also benefiting. Prior to the advent of NFV, workloads that required specialized networking functionality were difficult to implement with high portability. The rise of software-based networking functionality makes it easier to move such workloads between different cloud providers.

Due to the nature of NFV being software based, rapid changes to network configurations become a simple contributor to growth, rather than a stumbling block to innovation. SDN has ignited a long term fundamental change to the network design. It has created a power shift away from the use of entrenched vendors. Customers and smaller, nimble vendors can now do network design at many levels that were previously version locked.

Ultimately, both SDN and NFV provide businesses and operators with more choice over the technologies they wish to implement, increasing agility and in turn being a catalyst for business growth. It is important to understand how SDN and NFV work , and how they impact the network. The goal with both SDN and NFV is to control the network logically with software, and minimize hands-on work with those network devices.

The author is Director for Systems Engineering, Brocade India