SDN: No easy journey.

By Kirsten Doyle – 4 JUNE 2019 

The software-defined networking (SDN) market is burgeoning, fuelled by a growing demand from industries across the board, as well as the increased adoption of cloud-based services, virtualisation and enterprise mobility.

The benefits of SDN are numerous: greater flexibility when maintaining, managing and controlling complex networks, increased efficiency managing data traffic, and the ability it gives service providers to develop highly programmable networks. These result in reduced operational expenses, and an improved customer service lifecycle.

Adrian Comley, GM, Dynamic Network Services at BT, says enterprise networking is at a turning point. “After 20 years of relative stability, we’re moving towards a new way of networking, away from the static infrastructure of the past, towards a more agile and hybrid model built around software-defined networking services that can better support the challenges of the digital future.”

SDN is a developing architecture that introduces the concept of abstraction of the network control plane – usually responsible for configuration, monitoring and management or signalling traffic – from the forwarding layer of the network, responsible for user data, says Collins Emadau, architecture lead, Enterprise Networking at Comstor Sub-Saharan Africa. “The building blocks for SDN include a digital network platform that relinquishes most of the agility of software, enhancing the flexibility of the network and improving its adaptability to emerging application changes and demands. For businesses of any size, SDN can provide the agility needed to drive the future of their business, delivering dynamic network services to match evolving applications, device, user and security needs.

A new way of working

Today’s networks are hardware-centric, adds Emadau. “Changes to a current legacy network require an equipment refresh, the addition of modules to activate a new service and replacement of hardware to scale services. Today’s networks do little to deliver insights out of the box, and depend on the integration of third-party tools and a specialised skillset to get meaningful data from the network for improved monitoring, management and security purposes. They also require manually intensive procedures to troubleshoot, resolve issues, update configurations, patch or upgrade software and optimise services, which is where most of IT’s time and money is spent.”

SDN provides the ability to deliver cheaper gateways at the edge, as most processing is now left to the cloud or centrally delivered software controller modules, says Emadau. “SDN architecture can effectively deliver high-bandwidth for data, with the flexibility to scale up or down depending on the application need. SDN includes embedded security, making it a more attractive proposition for customers.”

According to George Prinsloo, regional sales manager for Networking at Citrix, other major benefits of adopting SDN include reduced operating costs enabled by centralised management, operational efficiency, and better hardware. “Moreover, with more companies moving into the cloud, there’s a growing need locally for the infrastructure to be virtualised. SDN provides a more scalable and flexible IT infrastructure, which allows businesses to develop and deploy new applications and services with shorter turnaround times than ever before.”

“With business environments becoming more connected and relying on technology, they also become strained where the switching and on-boarding between devices becomes a security challenge, with multiple devices connected at the same time sharing copious amounts of data each minute,” adds Riaan Graham, sales director for Ruckus Networks. “To deal with wired and wireless connections, these businesses require systems that will help better manage the pressures and traffic flow. SDN makes it easy for an enterprise to manage its entire network in a centralised platform allowing the organisation to be more productive and efficient. In addition, as platforms become more digital and BYOD is fully integrated into the business, security becomes a challenge. However, with SDN, managing the network’s security becomes easier; with a central control point, security and policy information can be distributed effectively. Central and automated administration of the network can be released, leading to the business saving on operational costs in the long run.

Fundamentally, SDN gives business the flexibility to reprogram the network to adapt new application demands through an open, programmable software stack. It provides a rich platform that can help drive the adoption of cloud, IoT and mobility, and also supports embedded security capabilities. “Businesses can build their own application stack that talks directly to the network through APIs, providing results-based outcomes vastly improved over a current legacy network integration model,” says Emadau.

Not just for corporates

Emadau adds that SDN has some compelling use cases too. “Some of the most disruptive use cases for SDN can be seen in small and-medium-sized enterprises. As an example, using SD-WAN allows for the implementation of low-cost dynamic private WAN networks over any available WAN connections, independent of service provider controls and network rigidity. In this use case, businesses can replace costly MPLS and dedicated point-to-point links with lower priced internet circuits (direct internet access) and cellular backup connections as complementary to lower the capacity and need for MPLS. SDN is attractive to service providers looking to take advantage of the promised benefits such as cost, flexibility and a pay-as-you-grow support model. They can leverage SDN in several ways: to deliver datacentre connectivity in customer-collocated and VAR datacentres to give them the ability to activate customer services with speed and agility; or in SDN-enabled optical networks where there are high-volume internet traffic demands driven by new service consumption models in markets such as media, communication, transport, travel, business collaboration and even for fintech applications. Service providers can also take advantage of SDN to transition the millions of customer-provided equipment-based links to SD-WAN connections, giving them a ready-to-go, extensible and agile platform to overlay additional value-added services. This allows legacy service providers to evolve into powerful managed IT providers to SME customers, providing open, intelligent, centralised management and service orchestration.

Brian Timperely, CEO of Sebata ICT Group, says SDN is all about control and management, and these are growing needs within almost all organisations. However, he adds a caveat. “If an organisation’s intention is cost savings alone, then SDN is probably not the right approach. While it provides greater flexibility and control of an internal LAN environment, it typically comes at a higher cost than legacy infrastructure. The added benefits of control, centralised management and scalability all come at a cost too, so efficiencies need to be weighed against the additional costs.”

Before you switch

So what are the steps to take before embarking on an SDN journey? Prinsloo says the transition of a company’s network could potentially prove to be a daunting task, and that’s why a smart, informed and strategic approach is needed.

Consider the impact on finance and capital expenditure, he adds. “The idea that SDN allows you to ‘build once and use many times’ sounds appealing, but doesn’t suit the way many businesses run their accounting policies. SDN requires not only a change to the datacentre, but also a change in the way overheads are managed, assets are written down and departments cross-charged. A shared-service approach to datacentre resources can present a challenge to the way some companies manage internal cost. In addition, companies must understand the need for change. Anything that offers consolidation and automation tends to make good long-term financial sense, but the ease of management, improved user experience and agility offered by SDN can have a much more immediate business impact. A move to SDN should bring with it great flexibility and resource efficiency, but do challenge suppliers to ensure their pricing and licence models are as flexible as their product. Seek out pay-as-you-grow licencing, burst packs and options for using third-party infrastructure in the cloud as availability zones.

Prinsloo also cites SDN ergonomics. “In the past, making developmental changes to the applications being delivered to the business was a complex cross-departmental process. Implementing a next generation network does disrupt this process and the skillset of the workforce. As the datacentre consolidates, so will job descriptions and functional roles – so consider how datacentre operatives will need cross-functional skills covering security, networking storage and related disciplines.”

No easy task

In Comley’s view, SDN is a never-ending task. “The first step is to accept that your network infrastructure is ever-evolving as your business moves forward and technology advances. Though it may take some investigating, there’s a need to develop a clear picture of what is actually happening on the business network. What applications or devices are using bandwidth? Are there performance issues? What’s priority traffic and what can use local IP breakouts? Armed with real-life insight into the network behaviour, you will be in a much better position to identify where SD-WAN, and related solutions, can help.”

The second step is to be prepared to handle the transformation while managing the complexity of the current environment. “Network change is hard. Small-scale trial deployments can be counter-productive, making it look deceptively simple. The reality is that this is going to make changes across hundreds of interdependent sites spanning multiple geographies, each with its own applications, varying service levels and user expectations. And the more changes that are made, the more scope there is for things to go wrong and for vulnerabilities to be created. What’s more, the skills needed for network transformation and security are in short supply.”

Knowing where to start requires an understanding of SDN building blocks, says Emadau. “The typical features needed from a n SDN infrastructure include software programmability and programming tools; management of the infrastructure no matter the location; support of open standards and vendor neutrality to ensure the investment stays in-house; cost of the physical controllers, edge gateways/ switches and integration elements required to deliver an SDN platform. All these can be overwhelming to a new customer and could affect the experience of transitioning to an SDN infrastructure. A reliable technology partner with an in-depth understanding of SDN can assist and better manage the financial risk for any business investing in SDN.”

What questions should businesses ask potential SDN vendors? Timperely says after explaining their business requirements to the vendor, they should be asking if SDN is right for them. “SDN is extremely useful to a business that is growing quickly and pushing digital boundaries. A good vendor will judge the need and make recommendations accordingly. All of the usual questions businesses should ask an IT vendor also apply: how much experience do they have, can they support the solution, reference sites and case studies, and, importantly, what are the potential limitations or downsides of the technology?”

What to look for

When shopping for a vendor to assist in your SDN journey, make sure that the chosen solution provides complete visibility across the network any time of the day, says Prinsloo. In addition, any good SDN solution should have in-built de-provisioning as a logical last step once the need for the provisioned resource ends. This will ensure that all extra overheads are constantly managed.

Businesses interested in deploying SDN need to ensure the vendors they choose have strong SDN knowledge, are able to deliver a solution that caters to the particular business needs and are also available to walk the journey with the customer as their businesses grows and changes over time.

Emadau says it’s important to understand whether the vendor and solution meet your business needs, will deliver the required agility, whether it’s open and programmable and delivers management capabilities, such as a dashboard to track and measure whether service levels are being met.

“The real question now for CIOs, is not if, or even when, they should start to develop a more flexible, dynamic network, but rather, how. It’s not a time for quickfire answers or leaps of faith – enterprises need clear guidance and practical support as they evolve the networks,” says Comley. “Businesses need to ask vendors some hard questions, including how, exactly, will they seamlessly deliver changes into the network management policies and processes? How will they maintain application performance, and prevent new vulnerabilities arising? In what way are they investing in their own infrastructure and security capabilities? How will they centrally manage, secure and automate a virtualised network? How are they going to monitor, prevent and self-heal incidents across the network? And, will they share their cyber security experience and insight to keep your business ahead of potential threats?”

As we move into the next generation of networking, responsible network providers recognise the challenges that enterprise customers face and will respond with a new way of delivering and securing network services for the future, says Comley. “Tomorrow’s successful companies will have a fluid, malleable network infrastructure without the traditional boundaries between LAN, WAN, datacentre, cloud and security. They will recognise that the future of networking is evolutionary and choose a partner who will help them make the right choices and move ahead with confidence.”