How Does SD-WAN Work?

SD-WAN (Software-Defined Wide Area Network) works by utilizing software and a centralized control function to handle the following three things:

Priority-based traffic
Service quality
Security requirements

Once traditional WAN services are virtualized, they are treated as a resource pool and SLAs (service level agreements) are met with advanced software-driven security to ensure high performance of applications. This can be accomplished with SD-WAN because it centralizes the rule definition and distribution process. The result is that it’s easy, cost-effective, and reliable to manage networks and policies, and increase business agility by intelligently directing traffic to any application, hosted at any location, simultaneously and with a single application.

A Deeper Look at the Workings of SD-WAN

That is the basic answer about how SD-WAN works. Now let’s dig a little deeper into some of the specific things SD-WAN gives.

Centralized Control

SD-WAN centralizes the separate control functions into either a cloud service, an on-premises application, or a remote branch. Having all the details of your network topology in one view offers continuous automatic monitoring, simplifies operations, and increases efficiencies.

Directed Traffic

While traditional WAN relies on simple routers to direct traffic according to access control lists and IP addresses, SD-WAN directs traffic down whichever specific network connection fulfills current policy requirements for flows or packets (such as security policies, quality of service or experience, priority of traffic, and failover scenarios).

Optimized App Performance

One way an SD-WAN directs traffic is by reducing the number of transactions applications and networks send over the WAN. This reduction includes streamlining data and its transport, managing evolving standards-based protocols (including HTTPS and SQL) and addressing issues such as available bandwidth and latency, dealing with jitter, and avoiding packet loss. This results in faster response times and end-to-end throughput.

Zero-Touch Provisioning (ZTP)

SD-WAN uses zero-touch provisioning to discover and set up new appliances in the network. It allows for branch offices or cloud-service locations to gain streamlined deployment through publicly accessible internet service. The deployment automatically integrates new appliances with existing appliances. At the same time, it still applies software-defined and policy-based provisions and restraints, including use of secure socket layer (SSL) protocol to protect access to the network.

Secured Connections

SD-WAN can identify and direct traffic directly and in tandem with next-gen firewalls, WAN optimization, VPNs, and web gateways that balance both performance and security. The centralized, global system based on a single policy automates secure services and makes them easily changeable for updated needs or to respond rapidly to a new condition.