SD-WAN vs. MPLS: how do they compare from a security perspective?

March 26, 2021  |  Mark Stone

This article was written by an independent guest author.

SD-WAN and MPLS are two technologies that are often perceived as either-or solutions. For many organizations, however, SD-WAN and MPLS can complement each other.

This article will define and compare the technologies, explaining how, in many cases, they work together.

We’ll also explore SD-WAN’s popularity and its role in enabling modern security architectures like SASE.

Defining SD-WAN and MPLS


Software-defined wide area networking (SD-WAN) is a distributed networking technology that provides a sustainable alternative to high-latency hub-and-spoke network topologies.

Before SD-WAN, hub-and-spoke networks directed branch office traffic to a centralized data center, often through MPLS dedicated lines, as remote and home-based workers connected through VPN. While this model worked well in the past when all applications were installed on the desktop or data center servers, the rapid proliferation of cloud applications and services overloaded MPLS circuits. This latency and poor user experience represent a significant roadblock to cloud optimization.

To address these issues, SD-WAN enables branch office and remote users to connect directly to the internet when a direct accessing resources hosted in the cloud.

SD-WAN uses software that makes intelligent traffic routing decisions based on priority policies and QoS settings. Its flexible mesh of network links can connect directly to the internet, the data center, or other branches depending on its application. SD-WAN uses a variety of transport services—including MPLS, commodity broadband services and LTE.


Multiprotocol Label Switching (MPLS) directs network traffic and data through a path using labels—instead of requiring complex routing table lookups at each network point. MPLS technology requires proprietary hardware and operates much like switches and routers. To make data forwarding decisions, MPLS uses packet-forwarding technology and labels (which virtually isolate packets).

MPLS is often implemented on high-performance, distributed networks and can deliver packets reliably with a high QoS (Quality of Service). With MPLS, packet loss for higher priority traffic is minimal and keeps an organization’s most important traffic flowing. For real-time protocols like VoIP, high-level QoS and reliability is essential.

The SD-WAN & MPLS comparison

When comparing SD-WAN and MPLS, the most significant distinction is the infrastructure: SD-WAN is virtualized while MPLS is hardware-based.

MPLS connections essentially operate like a dedicated leased line and offer lower packet loss but higher bandwidth costs. SD-WANs, on the other hand, can handle multiple types of network connections, including MPLS lines.

While MPLS is distinctly reliable, agile organizations requiring distributed networking capabilities are turning to SD-WAN to augment their existing MPLS circuits. 

SD-WAN’s scalability, performance, visibility and global availability are attractive benefits to most businesses. Besides, SD-WAN can be quickly put in place and adjusted to suit business requirements.

Private-based networking technologies like MPLS will always be an attractive option for organizations with specific security and connectivity requirements.

It’s important to remember that SD-WAN can incorporate MPLS into its infrastructure but not the other way around.

Can you combine the two options?

Absolutely. Combining MPLS with SD-WAN allows companies to gain the best of both worlds. Less-critical data can be transferred through the internet, while sensitive real-time information can be automatically routed to the MPLS.

The speed and reliability of MPLS sometimes aren’t compelling enough to use for all connectivity, due to the costly implementations. But SD-WAN is affordable and typically less complex. With a hybrid approach combining the two options, companies with multiple locations can be more selective about branches that require MPLS. Companies lacking connectivity options can maintain reliability and speed with a combination of networking options interlinked with SD-WAN.

For many organizations’ SD-WAN deployments, MPLS is still used to connect branch offices to the data center. SD-WAN controls the data flows for those circuits along with the commodity internet lines they are using to connect branch offices directly to the internet.

SD-WAN vs. MPLS should not be considered an either-or or versus, but rather a complementary solution. 

Why SD-WAN is growing in popularity

As an organization’s attack surface broadens to meet the demands of a transformed workforce, more and more cloud applications and other services are being added to their networks. This shift, combined with the need to manage security controls, SD-WAN’s popularity is skyrocketing as today’s internet lines are faster and more efficient than traditional MPLS. Improved connectivity and redundancy are more attainable.

Not only does SD-WAN offer organizations lower IT costs, but companies gain increased productivity and a better user experience.

Despite the benefits, current SD-WAN solutions often cannot keep up with the modern security challenges as their networks expand. Today, security must be fully integrated with the networking functionality of any SD-WAN solution.

SD-WAN solutions should provide a cloud backbone network with multiple tenants and regions to improve networking delivery between the SD-WAN edge devices. However, not every company may require this type of network architecture. Typically, companies with multiple divisions or those that seek to isolate and apply different rule sets based on types of traffic (a manufacturer separating IT from OT traffic, for example) will gain the most benefits.

How SASE and SD-WAN go hand in hand

When integrating networking and security solutions into a single unified platform, SD-WAN is required for SASE. SD-WAN services are a critical backbone of the Secure Access Service Edge (SASE) model, which places network controls on the cloud edge instead of the corporate data center.

With SD-WAN, SASE can transform network security into something more consumable and scalable while reducing cost and management overhead. SASE platforms can deliver SD-WAN as a service, limiting requirements for outdated network security hardware.

But before any SASE solution and SD-WAN deployment, organizations must be willing to take the time to fully evaluate their networks. Essentially, you’ll want to identify which users and applications are accessing your network and for what purpose.

Adopting SASE’s holistic network and security approach is a significant step.

Learn more about how SASE and SD-WAN are playing a key role in digital transformation and reshaping security.

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