As technology has continued to evolve, from the dawn of mainframe computers in the 1930s and PCs in the 1960s, to the predominance of smart end-devices and the growth of machine-to-machine technology today, so has the complexity of the networks that enable these computing paradigms.

Networks have had to keep up with these changes in technology as the world has moved from private networks to the more common shared networks and the open Internet of today. These network paradigm shifts have given rise to new network architectures such as high-performance Multiprotocol Label Switching (MPLS)-based virtual private networks, while the demands for ubiquitous, always-on access to networks from multiple devices has begun to drive the move away from hardware-defined networking.

This trend has given rise to software-defined networks, which could have a more profound effect on the networking landscape than MPLS did.

The software defined network, or SDN, while still in its infancy, is already bringing a very different dimension to networking. Although this technology is evolving and developing, it has been an engineering phenomenon over the last five years. Analyst firm Gartner even labelled SDN a trigger technology as early as 2012 in its “hype cycle” for networking and communications.

And now, as it goes mainstream, many industry pundits are already predicting big things for SDN. For instance, spend on SDNs is estimated to grow from US$360m in 2013 to $3,7b by 2016 — a compound annual growth rate of 117%. And this exponential growth is expected to continue into 2018, when spend is estimated to reach $35b.

The basis for these predictions lies in the open architecture of SDNs. Through OpenFlow, an open-standards communications interface that differentiates between the control layer — responsible for network routing — and the forwarding layer, which allows traffic to move through the network, SDN architecture offers direct access to and the ability to manipulate the forwarding plane of network devices. This capability means that we can start moving away from the closed network architectures that have created the lack of flexibility to deal with the demands of the modern IT environment.

Simple, open, better
The open interface of an SDN is created by using open-source control software with customisable application programming interfaces that run on general purpose networking hardware. With centralised software that reads conditions and data requirements, SDN only requires simple hardware that can “speak” to and react to commands from the software. So, by taking a piece of software and putting it into the centre of a network, network administrators can analyse and adapt the forwarding layer to move it in line with prevailing conditions and requirements. This takes network control out of proprietary network switches and delivers the flexibility needed for network customisation and cost reduction.

This is achievable as an SDN is able to take a request, get it to the destination and return a response in a cost effective and predictable way. This is possible because data transmitted across the network is now controlled by software that runs on many pieces of networking hardware, giving the network the ability to “recognise” data, prioritise it and then transmit the packets securely.

SDN is also adaptable as it offers a degree of programmability. This means a network can change to meet the dynamic conditions of the modern business environment. Network administrators are also able to configure the network across disparate hardware and can ensure the right quality of service to deliver a predictable experience for different types of data that require different configurations.

The cost reductions achievable with SDN will also be a major game changer as general-purpose hardware can now be used to run modern networks. This also offers greater flexibility to change and customise the network to fit the environment as network components can be moved around easily. In addition, SDN offers the ability to customise and deploy applications and solutions more rapidly as it gives network administrators full control of the network environment.

As such, any organisation that is dependent on the flow of information and spends significant budget on networking is a likely candidate for SDN. Early adopters of this technology would therefore be media companies, technology and telecommunications providers, banks and e-commerce providers.

The adoption of SDN has the potential to change the life of network managers in these companies by simplifying the network environment. As it has become more complicated and cluttered, the tasks of network managers have also become more complicated, especially when trying to manage this environment, apply rules and conditions, or add devices. Through the one-click functionality offered by SDN, network managers will be able to deploy and change conditions as the need arises, which has the potential to improve operations by an estimated 35%. The network will then adapt to give users the same predictable experience as before.

Over and above this, SDN offers other important benefits. According to a poll conducted during an industry webinar hosted by Markus Nispal, who writes for sdncentral.com, with more than 700 registrations that included integration partners and customers from different industries, the benefits of SDN included improvements in network automation of up to 45%, a 35,8% improvement in operational costs and a 22,5% increase in simplicity. Respondents also reported that SDN helped to speed up the deployment of applications by 45%, increased performance by 26% and delivered savings on infrastructure of up to 26,7%. With tangible benefits like these, all predictions point to a rapid adoption of SDN.