SD-WAN Architecture Options

The SDN technology started in the data centers. However, since then, has moved to the wide area network. SD-WAN (SDN for WAN) architecture is becoming the new hot topic in Australia because of its various benefits. Among other things, it promises to bring together two things that were worlds apart before:

  • Improving branch connectivity
  • Lower WAN costs

As a leading SD-WAN provider in Australia, we’ve had the opportunity to evaluate dozens of SD-WAN product offerings. Many network planners try to design an SD-WAN architecture that incorporates both the Internet and MPLS. Yet, this often leads to poor performance of cloud and SaaS applications since it requires the backhauling of traffic from MPLS, to the data center, through the internet, and back again.

SD-WAN Architecture Essentials

Companies have been looking for ways to improve their networking environments, speed things up, and make businesses more profitable for a long time. Investments in flexible, open cloud solutions have been on the rise and SD-WAN is a similar effort toward seeing these benefits in the data center architecture.

The main advantages of SD-WAN architectures are for business branches located far from each other. If a business has one main office and several branches, this is the best option. The traditional WAN architecture is notorious for being complex and expensive. However, SD-WAN brings the costs of networking down, provides much more visibility and control, and simplifies processes with centralized management and zero-touch deployment.

The main selling point of SD-WAN architecture is the fact it can communicate across all network endpoints, without needing additional protocols and other external mechanisms.

The Three  SD-WAN Architecture options:

Learning the ropes of SD-WAN is the first thing that will help you determine whether this new tech will improve your business’s WAN. There are three types of SD-WAN architecture. They can’t be sorted from best to worst since all of them are good for certain applications. It all depends on your needs and expectations.


1) On-prem SD-WAN

Definition: Premises-based SD-WAN solutions are great for small, localized businesses. These are usually executed by introducing an appliance to the site, which is used to ensure SD-WAN functionality. It shapes the traffic within the premises in real-time, which brings costs down and drives performance up.

Another characteristic of a premises-based SD-WAN is that it has no connectivity to a cloud gateway. It can only communicate to the other sites of your company.

Use case: This solution will benefit you the most if your company is hosting all of its appliances on site. If your business does not require any cloud applications, the cloud-enabled SD-WAN solution would just increase the costs without a good reason.

In such cases, the best option is to keep a smaller MPLS network and use it for real-time apps. On the other hand, the public internet can be controlled by SD-WAN and utilized for everything else.

On-prem SD-WAN Benefits:
  • It eliminates cloud-bandwidth costs or lowers them significantly.
  • Provides a better connectivity backup, so it improves disaster recovery.
  • Enables traffic shaping in real-time and improves the performance of WAN apps.
  • Offers ISP/Multi-circuit load-balancing.


2) Cloud-based SD-WAN

Definition: The cloud-based SD-WAN architecture is similar to the premises-based in that it also has an onsite SD-WAN box. However, this appliance also has a connection to a virtual (cloud) gateway. This setup allows your company to have the best of both worlds, so the reliability and performance of your cloud applications will be significantly improved.

The most common cloud apps and cloud providers include AWS, Office 365, Salesforce, etc. and the cloud gateway gets networked directly to them. This way, they can perform much more effectively than before. This also gives you added security in case your internet connection fails while you’re using a cloud app. The gateway will keep the cloud session active and allow you to continue to work. Moreover, if your company has two separate internet connections, the beauty of SD-WAN is that it will instantaneously route your cloud apps to the working circuit.

Use case: If your company is using demanding cloud apps such as DropBox, Azure, Office 365, AWS, etc. this SD-WAN architecture will suit you. The solution that a lot of businesses go for is a small MPLS network for on-site real-time apps and a cloud powered by the public internet for everything else.

Cloud-based SD-WAN benefits:
  • Improved DR through a better connectivity backup.
  • Improved performance of all WAN apps via traffic shaping in real-time.
  • Multi-circuit/ISP load-balancing
  • Cloud gateways improve performance and reliability of cloud apps.


3) Cloud Plus Backbone

Definition: Having a plan B is always a good idea, isn’t it? This option provides you with one, offering many benefits along the way. Cloud-based architecture plus a backbone means that there will be an SD-WAN box on-site, which will be connected to an SD-WAN provider’s point of presence (POP). This is where your traffic will jump on your provider’s private, high-speed, network backbone.

What the benefit from adding another point your data needs to traverse? Your information is guaranteed to always maintain low levels of packet loss, latency, and jitter. This is beneficial for the entirety of your traffic, but you will see most improvements in your real-time apps providing video, voice, and virtual desktop.

This backbone solution can also connect with cloud-based apps mentioned before, which will additionally improve their efficacy.

Use case: This option is the right choice for companies who greatly depend on real-time apps and want to get rid of high-cost MPLS circuits, but do not want to risk relying completely on the cloud.

Cloud plus backbone SD-WAN benefits:
  • Improved performance of real-time apps.
  • Benefits of cloud gateways.
  • Real-time traffic shaping.
  • The connectivity backup improves DR.


Final Thoughts

There isn’t a bad SD-WAN solution, but there is the perfect SD-WAN solution for your business. The key is to have the knowledge to figure out which one.

Learn more about SD-WAN architecture.