Top 3 SD-WAN Architecture Types

Software-Defined Wide Area Network (SD-WAN) architecture is rapidly becoming a popular solution for organizations seeking to improve network performance and increase scalability. SD-WANs use software-defined technology to manage network components, including firewalls and routers and perform software and firmware upgrades. There are several types of SD-WAN architecture, all of which enable enterprises to leverage a variety of services to connect users with their applications. An SD-WAN solution is centrally controlled to securely, safely, and quickly direct site traffic across the wide-area network. 

SD-WAN’s virtual overlay is used with other technologies, such as LTE, MPLS, or broadband, to automatically manage and optimize network traffic by switching routes to reduce latency. Network traffic is adjusted to meet application demand, resulting in improved responses. 

Selecting the appropriate type of SD-WAN architecture for businesses looking to upgrade from traditional WANs can be daunting. This blog will explore the types of SD-WAN architecture options available and which solution may be a good fit for your company. 

Types of SD-WAN Architecture

While several SD-WAN architectures are available, the following are the most commonly used: 

On-Premises

On-premises SD-WAN uses the hardware located at the site, giving personnel immediate access to the network’s hardware components. This configuration doesn’t utilize the cloud and can only connect across the company’s remote locations. As a result, this architecture is well-suited for organizations seeking to replace or increase the efficacy of a pre-existing private network. 

Since the on-premises solution is privately deployed, it’s the least expensive of the three main architecture types. There are no fees for cloud-enabled bandwidth or extra costs associated with higher-tiered services.  

The implementation of the on-premises SD-WAN is very straightforward. The only required equipment is an on-site SD-WAN controller registered to the centralized location to which the remote sites connect. 

This option is highly secure since there are no connections outside the private network. There is also total control over the SD-WAN equipment and remote connections. However, the organization is entirely responsible for monitoring and maintaining the SD-WAN controller environment for efficient communications.

Other benefits to the on-premise SD-WAN architecture include improved WAN apps’ performance and disaster recovery due to local connectivity backup. On-premises SD-WAN also allows traffic-shaping in real-time. This SD-WAN architecture also allows meshed VPN connections with associated sites automatically. If cloud-based applications aren’t used, this SD-WAN is an affordable and easy-to-maintain option. 

Hybrid SD-WAN

In the gateway configuration, the SD-WAN controller communicates to a cloud gateway. While this is a virtual connection, real-time traffic shaping benefits are still realized, as in the case of the site-to-site SD-WAN. However, rather than a focus on the private network, the gateway SD-WAN option focuses on cloud applications. 

With cloud connectivity, the gateway SD-WAN architecture features increased performance and reliable applications. By utilizing gateway SD-WAN, companies can quickly and easily create private connections between their branch locations and the cloud.

Another benefit of this architecture is that the gateway can maintain active sessions during an internet outage. Once connectivity is restored via circuit backup, the SD-WAN reroutes the session, preventing workflow interruptions. 

This SD-WAN option is best for meshing sites with an existing firewall when migrating to the cloud. It is also an excellent solution for single-site organizations, entire cloud-enabled operations, or organizations with multiple locations that don’t require site meshing. 

Related: How SASE & SD-WAN Relate and What It Means for Your Organization

Cloud SD-WAN

Cloud SD-WAN is transforming the way businesses communicate across wide area networks. While this SD-WAN solution provides the benefits of both on-premises and gateway architecture, the addition of powerful cloud technology increases the network’s efficiency, performance, and reliability.

Robust cloud SD-WAN applications reduce latency, improving user experience. Network performance is monitored and controlled using real-time analytics, allowing businesses to adjust traffic flow as needed. A significant benefit to cloud SD-WAN is built-in redundancy. This feature ensures that network interruptions are kept to a minimum, as traffic is automatically routed in the event of a failure.

As in the case of on-premise and gateway SD-WAN, the cloud SD-WAN configuration uses a central controller that connects to the service provider’s nearest network point. Branch connectivity is established through the internet to public and private enterprise clouds that provide data storage and software. The cloud-based connectivity also enables users to connect remotely on demand from any location. 

Why Are Organizations Switching to SD-WAN?

Many businesses have used Multi-protocol Label Switching (MPLS) to connect remote branches. As a popular network technology for over two decades, MPLS provides scalability, improved bandwidth utilization, and reduced network congestion.

However, there are several disadvantages to maintaining the MPLS solution. First, MPLS is considerably more expensive. MPLS circuits are also fixed and not easily modified once they’re in place. 

Additionally, while MPLS is an efficient solution for point-to-point connectivity, it loses its efficiency if the network transitions to the cloud. This lag is due to the need for traffic routed first to the central hub location instead of flowing directly to the cloud.

The migration to SD-WAN is also driven by deficiencies in the current IT infrastructure uncovered during a comprehensive network evaluation. For instance, a misdirected or incorrectly configured firewall can result in longer response times, less uptime, and a much greater risk for the whole network.

A significant advantage of SD-WAN is that gateways can be deployed in the public cloud, reducing costs and improving the reliability and availability of the network. In the MPLS scenario, organizations must deploy hardware controllers on site, and accommodations are needed for rack space, power, cooling, and physical servers. 

One of the biggest challenges faced by organizations maintaining MPLS networks became evident at the onset of the pandemic. The proliferation of remote workers using their home broadband congested the company’s internet gateways. This unexpected issue forced many managers to reevaluate their network operations and seek more efficient architectures. By 2020, only 58% of companies surveyed about their network infrastructures were still using MLPS, compared to 82% in 2018.

As a result, many organizations are transitioning to an SD-WAN architecture to harness its cost-effectiveness and performance. SD-WAN architecture continues to be a popular upgrade solution for many organizations that find that traditional WANs are inefficient and unable to keep pace with their networking needs. 

The migration to an SD-WAN architecture should also be considered by organizations using cloud-based applications and are increasingly expanding into the digital space. This technology enables software-based application management, connectivity, and services between data centers and remote branches or servers in the cloud. With SD-WAN, administrators can easily and quickly make necessary connectivity modifications and add branches as needed without dispatching technicians to the physical locations. 

According to recent research, the SD-WAN architecture market could reach a value as high as $8.4 billion in 2025. This amount is not unexpected, considering that enterprises can realize increased productivity and decreased IT costs on an SD-WAN platform. 

Related: Comparing SD-WAN vs. MPLS

Choosing a Suitable SD-WAN Architecture Type

Choosing the right SD-WAN architecture for your organization’s needs is essential, as it affects your network’s performance. When selecting an SD-WAN architecture, it is crucial to consider the following factors:

Distance and number of locations

If the company has just a handful of local offices, investing in an expensive SD-WAN solution may not be economically feasible. Conversely, larger organizations with widely dispersed locations with plans for additional expansion would benefit from a cloud-based SD-WAN’s higher performance and reliability. 

Upfront costs and long-term savings

On-premise and hybrid SD-WAN solutions typically require higher upfront costs due to equipment purchases or leases. Conversely, cloud SD-WAN solutions have lower setup costs since the provider’s equipment is already in place at remote data centers. However, cloud SD-WAN architecture also requires ongoing monthly charges to maintain the connection. 

Data security

The type of SD-WAN architecture selected must ensure the secure transmission of sensitive customer data from within and outside the network. Opting for an SD-WAN architecture with advanced features, including encryption, authentication, monitoring tools and the SASE framework, can reduce the likelihood of a breach or unauthorized access and keep your customer’s data safe. Cloud-based SD-WAN vendors integrate more robust security measures in their networks.

Related: What are the benefits of SASE in your business? 

Choose an SD-WAN Partner That Adapts to Your Needs

Upgrading to an SD-WAN architecture optimizes network performance for organizations with remote branch locations. While legacy WAN systems are more expensive and complex to implement and maintain over distances, SD-WAN reduces recurring network costs while providing efficient centralized management tools to monitor, troubleshoot, and re-route traffic as needed between locations. 

With a greater understanding of the three main types of SD-WAN architecture and their key benefits, you can decide which option is best for your organization. If you need assistance determining which SD-WAN solution is suitable for your infrastructure, the right partner will present several SD-WAN architecture types that fit your network requirements.

BCM One offers the best-managed SD-WAN services for your company, with the strong security credentials and deep security expertise that is essential to your company, alongside a scalable network that is crucial for organizations moving toward a more digital realm. 

Experts from our team will assess your existing infrastructure and requirements before designing a tailored solution to suit your business needs. BCM One offers expert assistance and implements a wide range of technology solutions. Contact us today to see how your company can benefit from our innovative SD-WAN solutions.