How SD-WAN can help in meeting increasing cloud-based demands
The traditional corporate WAN (wide area network) architecture became prolific in the client/server architecture era. We designed and built WANs to largely support branch-to-datacentre. On paper, these often looked like Clouds, but they are in effect hub and spoke networks – the hub being the data centre. This worked reasonably well when most of our applications were hosted in one or two datacentres, and access to the Internet was centralised and only available through the Data centre firewall.
Unfortunately, with the increasing use of the cloud this architecture has become costly and inherently inefficient, ultimately compromising application performance, business agility, and employee productivity. Most significantly the WAN is becoming a blocker to digital transformation, rather than an enabler.
The rising demand for cloud connectivity and Internet access at the branch is driving the need for a new architecture – one that SD-WAN (software defined – wide area network) is attempting to solve. So, what is it?
SD-WAN decouples the application from the underlying network transport. Doing this provides an ability to run any application over any transport or combination of transports. This could be MPLS (multiprotocol label switching), the Internet, mobile or even satellite networks. This ability allows SD-WAN to connect branch offices and remote sites in a different way to the traditional hub and spoke model, typically by creating a Hybrid WAN – one that includes at least two WAN connections from each branch office and leverages two or more different networks (e.g. MPLS, broadband internet, 3G/4G, etc.) – and where all branch WAN connections are active.
The SD-WAN centralised policy controller develops an application aware overlay network based on the underlying transport networks. This enables the SD-WAN to provide application-driven intelligent path selection across the WAN links based on policies centrally defined on the controller. For example, VoIP (voice over internet protocol) through the QoS (quality of service) enabled MPLS network while Office 365 and Facebook across the broadband Internet connection. This allows the SD-WAN to balance loads across the WAN connections, or to monitor application performance and send traffic over the lowest cost or the most reliable WAN links, depending on application requirements.
Cloud-based applications can route directly to and from cloud services and branch locations, instead of through the traditional route of a centralised Internet connection. SD-WAN ensures that branch offices and remote sites are configured consistently to connect users to applications while assuring security compliance and optimising network and application performance, reducing complexity and costs in the process.
What about the business benefits? The SD-WAN solution can improve network and application performance and availability, especially in relation to cloud applications and services, while providing cost-effective bandwidth at the branch.
But the real benefits are in providing cost-effective delivery of business applications and cloud-based applications and services through automated service provisioning, resulting in greater enterprise productivity and business agility. It is this business agility that will enable digital transformation to happen. Being agile is now key to business growth – this agility has enabled many enterprises to disrupt and quickly gain market share.
Traditional WANs are unable to provide the agility to drive the improved performance and speed of change business now requires. SD-WAN solutions are beginning to meet these challenges, creating better, agile solutions that can adapt quickly to meet our growing need for faster change and cloud delivered applications.