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A closer look at Software Defined Wide Area Networking

To understand SD-WAN, we first must understand what Wide Area Network (WAN) is. When you have an office in a single location with computers and devices connected to each other, this is called a Local Area Network (LAN). Organisations with multiple branch locations and offices would need to connect these local networks over a great distance for them to communicate with each other, this design is called a Wide Area Network (WAN). Essentially, a WAN is a network of networks – the internet is the world’s largest WAN.

For the past two decades, organisations have powered their WAN using a technology called Multiprotocol Label Switching (MPLS) to connect their networks via private, dedicated links.


SD-WAN represents an evolution of the MPLS technology, separating the network control and management process from the underlying hardware, and transforming into easily configured, easily deployed software. In many ways, SD-WAN can be seen as a software overlay of MPLS technology that is applicable to wider scenarios.

Organisations looking for more flexibility in connecting remote networks would benefit greatly from an SD-WAN setup. SD-WAN is a virtual WAN architecture which allow organisations to leverage different types of network conditions to securely connect users to their cloud applications or databases. It’s a traffic light system that give green lights to a courier with emergency medical supplies so that it’s not congested with lower priority trucks delivering junk mail.  

SD-WAN brings secure, private connectivity agnostic to all kinds of links and providers and is cloud aware. Compared to MPLS which handled failure scenarios with additional backup links, SD-WAN handles them with real-time traffic steering based on an organisation’s centralised policy, with multiple redundancies, failovers, and a system that intelligently load balances and manages mixed traffic.

SD-WAN technology transforms rigidly configured WANs into an agile, software-defined edge topology.

Benefits of an SD-WAN can include:

  • Lower costs compared to MPLS
  • Increased bandwidth due to connection agnostic
  • Manage multiple types of connections including broadband, MPLS, 4G/5G, and satellite.
  • Higher performance and availability/uptime
  • Better performance for smaller, remote locations
  • Quicker provisioning and rollout

As organisations transition to hybrid and remote working, users become more distributed and the demand for anytime, anywhere access to applications increases exponentially, as are the needs for enterprise networks to meet this increased demand. The reliance on cloud applications and infrastructure also means attack surface has expanded, and traditional approaches to centralised network and security can no longer keep up.

SD-WAN presents a cloud-delivered solution that is flexible, scalable, and intelligent; It addresses the challenges faced by traditional MPLS in the face of a rapidly evolving cloud landscape. By providing a centralised management console that connects users and business locations through varying service providers, SD-WAN creates a seamless and secure network with greater control.

    By leveraging SD-WAN, organisations can remove the roadblocks presented by traditional WAN infrastructure and continue to grow and expand their network to hybrid and multi-cloud environments with flexibility and security.