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How does SD-WAN Work? The Details You Must Know...

January 9, 2020

SD-WAN makes the typical networks “agile” from “fragile”. It is actually an innovative networking technology of building and managing the overall WAN with encryption and complete data security. It’s the easiest way to routing in the cloud network. In fact, SD-WAN is the ground level in this vast world of cloud networking. Therefore, it’s essential that you must be aware of how SD-WAN works to match the pace of today’s networking requirements.

SD-WAN is defined as the “Software-Defined” Wide Area Network- since often, the programmatic interfaces are integrated within these solutions for overall functioning. The best part is that you don’t require different devices for performing all the operations. SD-WAN is an all-in-one solution that manages all functions- from the configuration to deployment to management, and monitoring.

As a matter of fact, every corporate HQ has its well-defined data center that hosts the key applications, like- SAP, business-level server, and other applications. And, SD-WAN connects these data centers to their branches and remote locations across different networks- often multiple WANs, LAN/WAN, and the cloud.

In fact, SD-WAN is a transforming wave that helps ensure the optimum level of performance, especially for critical applications, without impeding the inch of security or data privacy. You can explore more information about SD-WAN past and present in SD-WAN Definitive Guide.

So, let’s start with this tutorial of how SD-WAN works...

How does SD-WAN Work- Best Possible Ways to Implement SD-WAN

It is quite easier to send SaaS and IaaS traffic across the internet through routers and acquire the best QoS for the end-users. However, not all traffic is made equal, and hence, it would be quite difficult to send specific data to the respective end-user. Result- the hitch!

Today, the networking wave is transforming and is switching from the “router-centric” approach to the “application-centric” way.  Everything is going under automation and is processed automatically to deliver the correct outcomes. And, SD-WAN is one of those listicles.

It is Software-Defined Wide Area Network- intends that an approach that is “programmed” with some sets of “software” to process automatically across the “WANs” to reach the correct destination. And, it’s all without the intervention of any manual action. Moreover, SD-WAN is application-aware. Thus, our objective is accomplished with SD-WAN successfully, isn’t it?

Succinctly, the job of SD-WAN is to connect the end-users to their respective applications- anytime, anywhere, and from any device. And, it uses centralized control management for intelligent traffic flow, accelerating applications’ performance, proper bandwidth utilization, unchecked data security, seamless collaboration, and great network connectivity.

Free Download: Increase your WAN insight to fit your high-level needs using this SD-WAN Playbook.

So, let’s discuss how SD-WAN works.

SD-WAN: The Application-Centric Technology

The SD-WAN makes use of the software to drive or route the traffic according to the business requirements of an “application”. The business requirements may vary:

  • Priority of the Application
  • Application Performance Required
  • Must-Enforced Security Policies

As compared to the previous model, SD-WAN handles traffic (across multiple networking connections- MPLS, broadband, and even 4G LTE) more smartly and works as per the business provisions to deliver the proper Application Priority, Quality of Service, and the Security- all together.

You don’t need to install a router for traffic flow and the firewall to keep the transactions secured distinctly. SD-WAN is programmed and automatically offers all-required services that will give the best quality of experience and improves business productivity. In addition, the IT-persons don’t need to step out to each location and monitor the issue. Since “automation” persists, so, once the rules and functions installed, they will be pushed to every location through the internet, and the issues will be resolved automatically. You can call it- “Zero-Touch Provisioning”.

So, besides the traffic prioritization (mentioned above), the SD-WAN incorporates a set of features that allows making use of the internet as a reliable and trusted form of “WAN transport”. It connects the end-users to the applications, regardless of they are hosted on the cloud or in the data center over any type of WAN transport service- broadband, MPLS, or 4G LTE.

Centralized Control Plane

As a matter of fact, the SD-WAN architecture separates the applications, the control & management functions, and the WAN transport services, such as- broadband, 4GLTE, MPLS, and even the satellite or microwave.

The WAN transport services are sometimes referred to as the Data Forwarding Plane, and the control functions are termed as the Control Plane. And, this control plane is centralized.

Centralized Control Plane: This centralized plane is the hub to store and to handle all information on the applications and traffic. It continuously monitors the WAN transport services and analyzes the network throughput and/or any jitter & latency or any packet loss. Moreover, it continually and automatically adapts how traffic is handled to make sure that the business perquisites for the specific applications are being met; and finally delivers the optimum experience.

Along with the above function described of the control plane, the security policies and the QoS are also there that guide how the application will reach the end-user. Those provisions are defined centrally and automatically programmed to multiple SD-WAN end-points at different branch stations. Consequently, predictable & consistent application performance and improved security are acquired.

Thus, if we accumulate the working of SD-WAN, then it will be-

A software-defined model that transfers the traffic across the entire wide area network according to the application priority, the performance, and the security policies combined with it. And, this will be applicable for the cloud as well. In fact, it has arrived for the cloud specifically.

Moreover, the control plane is centralized that audits the traffic flow automatically & break-free and delivers predictable results. And, with this model, it is more flexible to add more remote sites, applications, and to change any policy anytime. Simply, it connects the applications to the users & the customers, irrespective of the place.

In the Nutshell

Summarizing all points, we put up the SD-WAN compilation as follows:

  • SD-WAN is a more intelligent application-aware or application-centric cloud model.
  • It works according to the business’s application priority and performance.
  • It eradicates the efforts of the IT-persons and offers Zero-Touch Provisioning.
  • It bridges the gaps (of any magnitude) between the applications and the end-users.
  • It is scalable and integrated with the quick wins.
  • It has the potential to reduce WAN transport and IT administrative costs.
  • Last but not least, it accelerates the agility, the business initiatives, the end-user quality of experience, and business productivity.

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