Nearly everyone in the IT field has awareness of software-defined networking (SDN), but is likely unfamiliar with how it works or what it means to a company’s technology division. SDN appears to have staying power due to its many advantages, and it is important to have a good understanding of this powerful tool.

The Basics

Explained simply, SDN is a way of centrally controlling network devices programmatically while decoupling the control of devices from the actual forwarding systems. Early SDN has now evolved into software-defined data centers (SDDC), since cloud data centers now manage most network devices using this method.

It’s useful to have an awareness of network functions virtualization (NFV), a current movement of managing network nodes in a similar manner. This is used mainly with load balancers, wide area network (WAN) accelerators, firewalls, routers, and intrusion detection equipment.

SDN vs. NFV

SDN and NFV are conceptually similar technologies but focus on different aspects of a network. SDN is ultimately concerned with routing traffic and data flow through the system as efficiently and reliably as possible by separating the management of devices from those responsible for forwarding traffic (data).

In contrast, NFV’s focus is on the network functions themselves. SDN would redirect traffic if part of the network was down or sluggish, whereas NFV would be used if a firewall needed to be reconfigured or moved to handle more capacity.

SDN Advantages

Using a centralized method of managing network devices is beneficial for systems with many devices. Large, complex networks become much easier to handle without constant supervision or intervention.

In addition, vendor-managed devices can be swapped out in favor of unmanaged switches. These are often far less expensive to acquire and the company can perform the management internally instead of outsourcing the task. In fact, a requirement of an SDN-designated product is that it must be vendor-neutral, per the governing body Open Networking Foundation.

Driving Forces Supporting SDN Expansion

A number of trends have blossomed over the last few years to prompt the use of SDN in tech. The following are worth mentioning, but would be highly difficult for traditional network and hardware management techniques to effectively handle.

• Data, application, and security management are moving to the cloud and data centers are used to manage this move.
• Agility is a necessity, and traditionally controlled devices do not allow such quick recovery or redirection to take place.
• Geographically distributed databases may live in public or private cloud, are spread across the world, and are accessed by a growing number of users.
• Big data is everywhere and must be available from anywhere in the world without latency.
• BYOD and the Internet of Things (IoT) are growing, and everything and everyone is connected.

Technology is all about evolution, and SDN is a tool that was designed as a result of this evolution. Networks must be scalable and supportable to any size. Businesses do not want to be tied to vendor-managed hardware, nor can they be patient with the delays or outages that are commonly seen as traditional systems fail to handle burgeoning traffic.

SDN is a necessary tool that exists to help with large systems and exploding data. Through the use of this powerful mechanism, networks become far more governable, reliable, and expandable to meet the needs of the business.