The Challenge

Add flexibility to a rail franchise operator’s network to cope with traffic peaks and new service rollout, and enable connectivity of remote stations.

The Solution

Full turnkey SD-WAN solution combining Silver Peak technology with Xalient consultancy, design, monitoring and management expertise.

The Results

An agile, high-performance network that lets the operator meet today’s challenges and realise tomorrow’s ambitions.


Britain’s rail franchise operators have to be ready for just about anything. An important sporting match, a popular festival — or an out-of-the-blue sunny weekend that sees everyone head to the coast — means extra crowds on trains and platforms. Whatever happens, operators need to ensure that services like ticketing and CCTV go on running flawlessly, to help passengers keep moving, stay safe, and enjoy their journey.

Supporting today’s needs and tomorrow’s ambitions

One major rail franchise operator is finding it much easier to meet those and other challenges since it started rolling out a software-defined network (SD-WAN) to connect its stations, depots, rail operations centre (ROC) and data centres. As well as delivering performance and stability to keep services available every day, the SD-WAN adds agility to the operator’s business.

To cope with peaks in demand, bandwidth could be increased and decreased on the MPLS network the operator used to rely on. However, the network provider needed up to three months’ notice, and levied a fee for every change. With SD-WAN, the operator can scale bandwidth or alter traffic prioritisation at short notice — as little as 24 hours plus time to test — and there’s no extra charge for doing so.

Among other challenges the operator faced was pressure from the Department of Transport to deploy a new centrally hosted ticketing system at all its stations — even at small stations in rural locations. And, like any ambitious operator looking to retain its franchise and win new bids, the company has a vision to improve the customer experience by rolling out new services, which could include public WiFi at larger stations.

Flexible connections to a software-defined network

Research into more flexible alternatives to MPLS led the franchise operator to SD-WAN specialists Silver Peak and Xalient. The operator liked the look of Silver Peak’s technology for software-defined networking — including its ability to boost the performance and utility of the existing MPLS network. The operator also liked the idea of counting on managed service provider Xalient  to supply the Silver Peak equipment and deliver SD-WAN as full turnkey solution. Because the Xalient solution includes consultancy and network design expertise to streamline rollout, as well as monitoring and management to assure smooth running, there was no need for the operator to add headcount or acquire new technical skills.

The first sites deployed on the SD-WAN were the operator’s data centres, ROC and depot, and a major station. The MPLS contract is still running, so dual connectivity at those sites is provided by adding a broadband internet connection alongside the existing MPLS access. Silver Peak’s intelligent technology optimises traffic routing across the two connections, helping the operator improve MPLS performance and ensuring that critical traffic, such as ticketing, is prioritised. Sites in locations where fixed-line broadband access is impractical, unaffordable or even impossible can be connected to the SD-WAN using 4G instead. This is how Xalient efficiently connected five of the operator’s stations dotted around the countryside to support rollout of the new ticketing system by the required deadline. Further sites continue to be connected to the SD-WAN.

Full steam ahead

As well as enhancing network performance and agility, SD-WAN features meet a variety of other needs. For the operator’s employees, for example, internet breakout at every site and efficient management of voice and video traffic ensures a high-quality experience of Office 365 and the collaboration features of MS Teams. The orchestration platform that controls and manages the SD-WAN helps the operator comply with the EU’s NIS Directive (security of network and information systems). In the event of a malware-based or other cyber attack, the orchestration platform allows quick and easy isolation of the affected network segment and prevent the attack from spreading. Orchestration also speeds and simplifies network separation on franchise termination, or integration when a new franchise is won. SD-WAN is helping the operator make best use of its current MPLS network but, once the contract expires, the operator will have the option of replacing all those connections with commodity broadband access. And instead of continuing to source all of its connectivity from one provider, the operator will be able to buy broadband connections from any provider according to criteria such as cost or quality, and rely on Xalient to manage all the providers on its behalf.

And whatever ambitions the operator may have to launch new services for customers and staff in the future, SD-WAN will deliver the bandwidth and traffic optimisation to support their achievement.