Differences between SDN and NFV

Posted on February 26, 2016 12:18 am

Few days ago, a friend in Zambia asked for my views on how Network Functions Virtualization(NFV) and Software Defined Networking(SDN) will be in the next five years.To be blunt, I told him no one can predict how the two technologies will be in three years let alone five.The closest predictions in tech nowadays that comes close to accuracy is two year at most and thats a fact we have to live with because the rate at which innovations are being churned, its hard to be a ‘tech prophet.’SDN and NFV technologies are interlinked, and often inaccurately used interchangeably.However, understanding the difference between the two is important to getting maximum business value from adopting either, or both. Thanks to the Zambia friend question, I would like to use this to explain the role of each technology and their use in context with other virtualization technologies that exists in the mainstream market.SDN history shows that it was an idea that came out of university campus networks. 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. In addition to that, web-based firms who were disgruntled with the sluggish pace of innovation in traditional networking began investing in SDN in order to get the scale and control they needed in their hyper-scale data-centres.  So, in nutshell, SDN was created by researchers and data centre architects.SDN is about controlling network hardware.On the other hand, NFV was created by large service providers to shift from hardware centric to software centric infrastructure. Software-based features speed up deployment of new network services, advance revenue growth yet reduce operating costs. Overall, NFV is about taking what used to be specialized hardware and creating it in software on commodity servers.

From my working experience, there are key similarities and differences between SDN and NFV.One of the similarity is that both technologies arose from customer demand for more flexibility and interoperability, rather than the advent of a particular technology. Another notable thing is that the two concepts emerged in quick succession. Also, they can be and are used together in conjunction with a variety of other new technologies. The key differences is that SDN separates the control plane that governs a network from the forwarding plane that sends packets through it, giving IT more control over the behavior and performance of their networks. SDN addresses the management complexity of rapidly growing and distributed networks by centralizing control and enabling programmability to achieve desired behaviors. Importantly, the standards-based decoupling of control and data planes is meant to allow separate purchasing decisions for software and hardware.NFV on the other hand takes the network processes that are traditionally associated with specialized proprietary hardware such as firewalls, routing and application delivery controllers and converts them to virtualized software platforms that can run on standard commodity hardware.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 and low cost feature upgrades resulting in rapid innovation in service offerings months or quarters instead of years or decades.

Just like SDN, the NFV architecture is meant to allow separate purchasing decisions for software and hardware.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.Thanks 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. And 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. In simpler language, SDN is a new way to manipulate the network, and NFV as a new type of infrastructure to be manipulated.

Contador Harrison