What SD-WAN and Why Need it

In this article, we will focus on providing you with everything you need to know about SD-WAN but were afraid to ask. And at the same time clarify Why SD-WAN is important

 Define what is an SD-WAN is, so let me start by redefining the job of the WAN. The job of the WAN is to connect users to their applications anytime from anywhere from any device and wherever those applications reside. But let's start by looking at the way we've built WANs for the past decades. Branch offices -where more than 80% of business and transactions are handled- connected to a headquarters based data center with a router over leased line connection which is usually based on MPLS. And that model was fine because all applications were hosted in Enterprise data centers.

Traffic was routed from sources to destinations based on IP address, access control list tables, and complex routing protocols. All of the control functions were distributed across all of the routers.

But traffic patterns have changed with the introduction of applications moving to the cloud, this could be enterprise apps which are hosted in Amazon web services or Microsoft Azure or Google cloud or software-as-a-service apps like salesforce.com, workday Office 365, Dropbox, and even Facebook and more. Sending Cloud traffic that is destined for the internet back to headquarters simply doesn't make sense, as this adds delay that degrades application performance and it consumes costly leased line bandwidth.

So the main question spins up here why not use the internet to reach out apps that are actually hosted on the internet??  This has driven the need for a more intelligent software-driven or software-defined model for the WAN which is SD-WAN.  Instead of routing traffic just based on addresses an SD-WAN is application-aware as it uses software to more intelligently route or steer traffic across the WAN based on the business requirements for an application

Traffic Steering Criteria

 The SD-WAN uses different criteria to route and steer the traffic based on which are detailed below:

§  Priority of the application

§  The Performance required.

§  Security policies that are required and must be enforced.

§  It has the right set of features also enables the ability to actively use the internet as a secure reliable form of WAN transport Even 4G/LTE in addition to broadband internet and MPLS services.

 The SD-WAN de-couples the WAN transport services which are sometimes called the data forwarding plane- from the applications and from the control function. This is a different scenario than the traditional router model where this was all combined in every device, also with SD-WAN this control function –referred to as the Control Plane- is centralized. The quality of service and security policies that dictate how an application should be delivered to the user are defined centrally and “programmed” automatically for multiple hundreds or thousands of SD-WAN appliances at the branch locations

Main Benefits:

Below points illustrate the main and major benefits of SD-WAN:

§  This leads to a more consistent setup.

§  Predictable application performance

§   More consistent and improved security across the WAN.

§  Agility and simplified policy management.

§   Adding locations adding applications changing policies and much more is so much easier than the old routers-centric model.

 The SD-WAN de-couples the WAN transport services which is sometimes called the data forwarding plane- from the applications and from the control function. This is a different scenario than the traditional router model where this was all combined in every device, also with SD-WAN this control function –referred to as the Control Plane- is centralized. The quality of service and security policies that dictate how an application should be delivered to the user are defined centrally and “programmed” automatically for multiple hundreds or thousands of SD-WAN appliances at the branch locations

Why SD-WAN?

It is about 70% of enterprise apps have moved to the cloud-hosted in public cloud infrastructures or consumed as a service –SaaS, however, enterprises also reported that they are not realizing all of the benefits of the migration to the cloud (around 85%).

What enterprises describing, are the application performance impacts caused by backhauling all application traffic back to headquarters which is the case with the traditional router WAN architecture as clarified above.

 Sending Cloud traffic that's destined for the internet back to headquarters simply doesn't make sense. An SD-WAN has the right set of features, allows enterprises to actively and securely use the internet as a reliable form of WAN transport to augment- and in some instances even replace MPLS services. As  applications proceed with their migration to the cloud and as traffic patterns continue to change, enterprises are realizing that there is a better way to connect users to their applications, a better way that improves business productivity and end-user quality of experience and customer satisfaction, a better way that accelerates business initiatives and digital transformation a better way that keeps up with changes and delivers new applications to thousands of sites across the clouds are far less time the better way that lowers overall when costs and that way is SD-WAN

In summary, an SD-WAN is a more intelligent Cloud-first way to build a WAN that improves business productivity, end-user quality of experience, accelerates business initiatives and has the potential to lower costs.