by Stuart Hardy, Business Unit Manager of EOH’s Carrier and Network Solutions Division

In a previous article we looked at the key demands and challenges that the modern network faces. We discussed briefly how next generation networks need to evolve. Now let’s look a bit more closely at this, and how software-defined networking is emerging as an important element in meeting the requirements of network integration and control, especially as the use of mobile devices continues to increase.

The modern network – all things to all things

The modern network needs to serve many masters, so to speak. Network access needs to be available on a range of client devices, often of the BYOD variety. This includes PCs, laptops, tablets and smartphones. It needs to be available over Wi-Fi and cellular links as well as wired connections. Network traffic now routinely includes voice and video as well as data, making application-specific traffic management an important issue to ensure acceptable performance. This is particularly true over bandwidth-limited WANs.

The essential characteristics of highly virtualised cloud computing need to be sewn into the network fabric, as it were, with allowances made for the demands of different cloud environments that need to work together – private, hosted and hybrid cloud infrastructures.

On top of all of this is the need for efficient network resource utilisation, and for those resources to be rapidly deployable and easily scalable.

The pressing issue of security

Next generation networks pose serious management and security challenges – especially for IT professionals who have grown accustomed to dealing with traditional (wired) enterprise networks that contain a limited number of locked-down client devices (mostly desktops) connecting to IT resources within the company within the firewall in a client/server architecture. In this traditional scenario security policies have been relatively straightforward to implement.

Not so with next generation networks. These need to accommodate mobile users accessing the network from a diverse array of devices and locations. These users will be accessing highly virtualised IT resources that can reside in a number of locations, from the company’s data centre, to a cloud service provider’s data centre, or some combination of both in the case of a hybrid cloud environment.

Next generation networks need to be able to securely handle not only geographically dispersed branch office locations, as in the traditional scenario, but also homeworkers and mobile users who are increasingly accessing Software-as-a-Service and other cloud services and running virtual desktops. This is a far more complex security scenario than the traditional one.

Software-defined networking as a wired/wireless solution

One of the key challenges facing enterprise networking is the unified management of wired and wireless networks, with the latter usually emerging as an add-on to the traditional LAN. Because of the large emphasis on mobile devices, high-speed and high quality wireless networks are becoming essential, meaning that ad hoc or add-on solutions are no longer acceptable.

Software-defined networking (SDN) – the hottest topic in networking at the moment – may be the best current solution for wired/wireless unification. Combining wired and wireless LAN control in a single SDN appliance could provide both the integration and granular control that will be needed in a mobile/BYOD dominated enterprise environment.

SDN separates the control layer from the hardware layer in a network, allowing the network to be provisioned and controlled programmatically. It provides an abstraction layer in a similar way that hypervisors and virtual machines do for servers and desktops.

The power and utility of SDN in the next generation network environment lies in the way that networking virtualisation effectively provides the missing link in the ability to define, provision and manage networks, and the applications and services that run on them, in a flexible and scalable manner.

It may well be, then, that SDN provides the most comprehensive solution for ensuring that next generation networks can meet all the challenges they face.


Stuart Hardy has been in the ICT industry since 1997, has been in the Telecommunications industry since 1997, intimately involved in product development, operations and product marketing roles. He has held Executive level positions in some of the largest Operators in South Africa and has founded and driven two successful start-up companies in the Mobile data and Wireless networking spaces. Today, Stuart is a Divisional Director for EOH in their Telecommunications sector.