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If You Are Still Puzzled; Here’s What SD-WAN Is All About!

What is SD-WANSD-WAN is one of the biggest trends of networking in recent years, and it’s just getting started. When it comes to the management of enterprise networks, there is almost no absolute assurance on the ability of traditional WAN transmission technologies like MPLS circuits to provide guaranteed bandwidth and QoS at the bare optimum, without interruption 24/7.

Amidst the increase in enterprise bandwidth demands flanked by a limited budget, it becomes a bit tricky and expensive for NetOps to actively manage priority traffic from HQs and data centers to various branch offices. Beyond what existed, the IT industry saw a need for optimization; an ability to reroute critical network activities around legacy infrastructure without tampering on the efficiency and security of the network.

And that’s where SD-WAN architecture comes in.

What is SD-WAN?

SD-WAN, which means software-defined wide area network can be referred to as an enterprise network messiah; here to boost the efficiency of internet transport systems or WAN connections (4G, LTE, MPLS, etc.). It is a virtual technology that capitalizes on the working principles of Software-defined Networking (SDN) to assess and determine the best routes distribute traffic across legacy enterprise WANs, to and fro the various branches of the enterprise, automatically. You may simply refer to it as an SDN overlay for traditional hardware-based

Consequently, it ensures that all users are connected at all times without unnecessarily prolonged slowdowns in service rendering. As well, it breaks down the complexity between network transmission systems and edge devices, which in most cases leads to faster delivery, thus increasing enterprise productivity and user experience.

How Does SD-WAN Architecture Work?

We can refer to SD-WAN as a central system for the AUTOMATIC control of network traffic – it makes the flows more straightforward. What makes SD-WAN stand out is its internet-based mode of operation, in comparison to the traditional connections that required the use of specialized hardware.

SD-WAN operates by treating the enterprise network as an entity deserving a principal focus and a higher level of traffic fluidity. To do this, the SD-WAN application acts as an overlay of the traditional routing links by extracting and automating all the network monitoring and management functions.

As a virtual overlay technology, SD-WAN is compatible with WAN transport services, and no matter how many links and network applications and edge devices an enterprise operates, SD-WANs are able to monitor and manage them concurrently.

What this implies is that, in a situation where there is a drop in the steady flow of network traffic in a WAN link, an SD-WAN protocol will automatically redirect critical enterprise through the best available route without interrupting enterprise operations across branch offices and data centers. As well, the flow of less critical data requiring less bandwidth usage is maintained in broadband internet.

Through this centralized control, SD-WAN is able to correctly monitor and manage multiple WAN links, and make the work less cumbersome for NetOps.

Types of SD-WAN Architecture

SD-WAN solutions are offered in various forms, and any you will be getting must possess some basic functionalities and capabilities, which serve as their overall notable features. The difference lies in the business environment for which each is most suitable. There are internet-based, MPLS-based and premises-based SD-WANs.

Internet-Based SD-WAN

With internet-based SD-WAN, users are free to choose any ISP of their choice, and the installed SD-WAN will make use of a portion of the provided internet connections. The major shortcoming faced in the use of internet-based SD-WAN is felt when company locations are long distances apart. Hence, network jitter, latency and packet loss might be experienced frequently in locations where there is unreliable internet access.


For this to work, an SD-WAN vendor places various proprietary appliances in all the branch locations. With those, a virtual IP network is created which the vendor can use to centralize and control all the network packets across company locations.

Premises-Based SD-WAN

This is most appropriate for smaller businesses. It involves the use of a single SD-WAN appliance to enable SDN capabilities in the WAN link(s) in use.

Modes of Deployment

There are three established modes of SD-WAN deployment: SD-WAN as a Service, Internet-based and Managed-service SD-WANs – each unique in its application, but as functional and capable as others. Choosing a deployment model can be a little tricky, and the subsequent success of your deployment might depend on your IT department, vendor, management, and your company’s global reach.

SD-WAN as a Service

A company can choose to acquire an SD-WAN service much like every other cloud-based service. Network providers such as Cisco provide businesses with the opportunity to integrate SD-WAN into their operations, in combination with additional security and stability of a private network. This eliminates the burden of purchasing and installing additional hardware or infrastructure in existing or subsequent branches. And as well, ensures faster, seamless connectivity between users anywhere around the world.

Internet-Based SD-WAN

Edge devices such as routers are either amplified with SD-WAN appliances or replaced with an SD-WAN appliance which will act as a link between the legacy WAN link and the enterprise network. In this case, SD-WAN practically acts as an overlay of the multiple links in use in the company, complementing the provided services.

Managed Service SD-WAN

Here, the company can acquire SD-WAN as a value-added service from a service provider. The provider is paid a cost that covers the installation and service delivery of the SD-WAN, as well as for the hardware used in the setup. One major difference between this and SD-WAN as a service is that managed service SD-WAN makes use of the public internet instead of a private network. Hence, the customer is not ultimately assured of internet security and reliability over long distances.

What to Expect

Though they are not without their blemishes, there are numerous benefits attached to running SD-WAN in your enterprise network. And the few below just gives an insight of what to expect if you should opt for SD-WAN services.

A Simplified and Centralized WAN Architecture

The complexity of legacy WAN links is gradually becoming less of a task to look forward to, and more of a bore. With SD-WAN, companies can eliminate network complexities through SD-WAN’s ability to simultaneously assess and monitor multiple network links from different ISPs in real-time.

Optimized Connectivity and Resource Use

SD-WAN enables companies to offload mission-critical traffic towards the network edge, to reduce latency and boost user-experience. The intelligence applicable to SD-WAN applications enables them to automatically move key applications to the best available links, while also assigning QoS accordingly.

Lowered Operational Costs

The use of SD-WAN can reduce the costs attached to running expensive MPLS links across all company branches.

Additional Security

With an understanding of the Internet of Things (IoT), it becomes easy to see why you need a system that smoothly manages your communications, networks and network devices via a reliable working relationship over the cloud.


In comparison to traditional WAN links that might take months to establish across locations, an SD-WAN link will effortlessly expand with your business across new locations without unnecessary delays, and also without a need for the installation of space and money consuming infrastructure. Also, SD-WANs are flexible, and as cloud applications create new demands, SD-WAN designs help them adapt to the new demands to offer solutions.


Types of SD-WAN Architecture

If your enterprise is not making use of cloud or cloud-based applications, then there’s probably no need for you to bother about it. Other than that, if you want to boost the efficiency of cloud applications and company productivity at a lowered cost, you should be considering the SD-WAN option, already.

While SD-WAN works to make WAN links less complex and more efficient, there architecture and design are a bit sophisticated and require technical expertise to assess. LiveAction is a trusted Cisco solution partner, with immense knowledge and experience in SD-WAN monitoring and management that puts the control right at the fingers of our clients.

Let us help you transition with confidence.