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Aug 07

SD-WAN Architecture Explained: An Overview and Components

Posted on August 07th, by Arpita Saxena 2 Comments
SD-WAN Architecture

Today, the higher bandwidth and data consumption have become the need of an hour. Especially during the peak hours, it’s quite arduous to manage bandwidth distribution over WAN. This is the reason that SD-WAN has become an imperative business component that helps businesses stay forefront by getting victory over bandwidth mismanagement.

4 Essentials of SD-WAN Architecture

Let’s initiate discussing the significant components of SD-WAN Architecture that most of the CIOs are counting today. These inlcude all the key points that will overshadow the challenges related to legacy systems, and other management concerns, associated with SD-WAN Architecture. Let’s get started! 

I. Key Steps to Build an Effective SD-WAN Architecture

Clear Vision and Implementation

Building an SD-WAN architecture requires a clear and balanced vision, as it is an integration of newer and older both technologies. Each system, router, controller, and other devices need to be replaced perfectly. Therefore, vision and execution must include:

  • Have complete transpartent idea about your business’s ecosystem.
  • Evaluate SD-WAN deployment models.
  • Briefing about workloads, performance levels, and SLA requirements.

Address Performance & Other Issues

While supplementing traditional network with SD-WAN, the connected devices will encounter with certain issues that are mandatory to be addressed. Hence, it’s essential to think over some prominent points, as:

  • Making a choice between on-premise or cloud-based model needs to re-look on your business’s every corner to evaluate things on the basis of latency, bandwidth, performance, etc.
  • Mission-Critical Data necessitates making sure that they are within SLAs, with reference to availability, latency, and performance.
  • Don’t overlook WAN optimization tools while contemplating about SD-WAN. They are indispensable in terms of performance, and other addressing issues.

Re-Examine Security Policies

With transformations in network and end devices of an enterprise, security ecosystem is also affected. The private network demands lower protection, as compared to when network is connect to public open network. You will acknowledge the great value, as:

  • SD-WAN has the feature that enables the organization to draft  uniform security policies across the enterprise.
  • The addition of SD-WAN will give a secure and balanced security ecosystem to the enterprises having patchy security outlay across their branches.
  • The fast deployment of security policies lets organizations set up the infrastructure in less time that enables faster response and higher agility.

Re-Build Monitoring & Analytics Tools

Analytics, statistics, monitoring, visualization capabilities are to be in-line and right to manage the traffic flow, policies, etc. This will deliver you good results, like:

  • Analytics and performance data leverage the network managers to acquire a good understanding of workloads, performance, and other significant factors.
  • Also, important attributes of SD-WAN monitoring incorporates QoS monitoring, endpoint & component monitoring, access management, and network data analysis, etc.

II. SD-WAN Architecture: The Graphical Illustration

SD-WAN Architecture

The separation of data forwarding and control planes simplifies the network traffic routing is the foremost benefit of SD-WAN technology.  Earlier, all-things were controlled by the data center that made the entire routing process complex and took comparatively more time. But, with the introduction of SD-WAN’s centralized orchestration feature, it’s pretty easier to orchestrate or manage thousands of routers via a single centralized platform. It leads to painless and fast update/modification of every router and WAN connection of the enterprise.

Previously, the branches were connected to the data center, and then the data center was connected to the cloud. So, the failure in a single leased line led to a traffic drop-down of the entire network. With SD-WAN, all branches are individually directly connected to the data center and to the cloud. In this case, if any of the MPLS leased line drops off, then SD-WAN will redirect the route that doesn’t affect the other networking lines.

In addition, as shown in the figure, MPLS, broadband, and 4G LTE- these three lines are individually in-operation. So, with SD-WAN it is possible. Without interfering any of them, a company can utilize multiple networks without any fear of latency, packet loss, jitter, and network failure.

III. SD-WAN Architecture Must-Have Components

  • Integrated Security:

    As the organizations are switching from limited internet usage to unlimited internet with no bandwidth limitation, security is the foremost concern. In other words, today, with SD-WAN, higher performance should be directly proportional to security compliance. Else, include the trusted SaaS applications, like Microsoft Office 365, that allows direct access to the local internet connection, while directing other traffic to the hub site.

  • Native Cloud Support:

    Cloud integration provides enterprises with a foundation to manage the network locally and on the internet. As an advantage, some of the SD-WAN solutions offer monitoring and smart routing at the application level in order to get high-quality user experience, even if the internet connection is not good. Some of the enterprises opt for the public cloud providers, such as AWS, that serve two options- initial connectivity to the cloud and the robust backup solution for the long run.

  • Virtualization:

    The current scenario witnesses with Virtual Networking Functions (VNFs), which is a single hardware platform to deploy multiple functions. The best part is that they will be upgraded with a list of newer features within a short interval to support all-new attributes and functionality. In short, virtualization empowers agility.

  • Automation:

    Automation is here in the current scenario to reduce complexity. And, most of the SD-WAN vendors allow automation via the central management portal, delivering the capability to provision new site fast, make amendments, resolve issues, and notify about the potential threats and issues.

IV. Types of SD-WAN Architecture


    This SD-WAN architecture connects only your enterprise’s websites- through an SD-WAN box or plug-n-play router. The on-site SD-WAN box doesn’t connect to any of the cloud gateways. De facto, it performs the real-time traffic shaping at each place (only your company’s multiple sites).

    Perfect for the organizations that have in-house applications and operations, not on cloud-based infrastructure. A common small configuration that accommodates- MPLS network for voice, video, or virtual desktop, while, the public internet, controlled by SD-WAN, is allocated for everything else.


    • Improved Performance of all WAN apps
    • Multi-Circuit/ ISP Load Balancing
    • Enhanced Disaster Recovery


    This framework comprises an SD-WAN box that is connected to a cloud or virtual gateway. Leverage the advantages of on-premise architecture (real-time traffic shaping & multi-circuit load balancing/failover), coupled with the features of cloud infrastructure- reliability and improved performance.

    Plus, the cloud gateway is directly in connection with the leading cloud providers- Office 365, AWS, Salesforce, DropBox, Azure, etc. In case, if your internet circuit drops down, then the cloud session will still remain active. Moreover, if your enterprise uses the secondary internet line, then SD-WAN will re-route your cloud application on to that secondary line, without losing your current session.

    Perfect for the enterprises using a large number of cloud-based services — such as Office 365, Salesforce or applications running on AWS.


    • Increased Clouds App Performance
    • Enhanced Cloud Apps Reliability
    • Multi-Circuit/ ISP Load Balancing


    Backbone always works as a resort. So, here cloud-based infrastructure supported with the backbone is a level above. This solution includes an SD-WAN box that connects your enterprise’s website to the SD-WAN provider’s nearest network point of presence (POP), where your traffic will be switched to the provider’s private, fiber optic, network backbone.

    Redirecting traffic to the SD-WAN provider’s private backbone ensures reducing the level of latency, jitter, and packet loss. This leads to an increase in the graph of network traffic’s performance. Plus, like the cloud-based architecture, the backbone is straightforwardly connected with the chief cloud apps providers- Office 365, and AWS, etc., which improves the reliability and the overall performance of those applications.

    Perfect for the enterprises that are on the way to eliminate their MPLS network and at the same time running a lot of real-time network applications. 


    • Mission-Critical apps on private backbone leads to the improvement in the performance of all network apps
    • Cloud-gateway- increasing the performance and reliability of cloud applications.
    • Multi-Circuit/ ISP Load Balancing


With an increase in demand of bandwidth requirement, and innovation- all enterprises are looking for the smart, reliable, agile, cloud-based, streamlined, and uncomplicated way for traffic and data transfer- SD-WAN is the perfect option that accommodates all these technological factors.

Arpita Saxena
Written by Arpita Saxena
Arpita Saxena is a Content Writer at TaraSpan. She likes to explore and read about the latest technologies to provide the knowledge to the audience and educate them with correct insight.


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    Girish Zunzunwala August 26, 2019 at 7:48 am

    Very useful and informative…

    Ritika Goswami August 28, 2019 at 7:49 am

    A superb set of information really good points are covered thanks for it keep sharing


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