Guide to an MPLS Migration to SD-WAN

An MPLS migration begins with assessing a business’s current network needs and costs. With that information, enterprises can implement phased rollouts to reduce downtime while testing SD-WAN performance. This approach helps ensure savings, security, and scalability.

Enterprises are increasingly transitioning from Multiprotocol Label Switching (MPLS) to Software-Defined Wide-Area Networking (SD-WAN) as networking technology evolves. This shift offers businesses unparalleled access to flexible, software-driven networks. In turn, they’ll benefit from support to meet the demands of both modern businesses and cloud applications.  

For many organizations, technology isn’t the only reason behind this shift. Succeeding in a digital economy requires rapid scalability, coupled with cloud-first applications that best suit the needs of a remote workforce. 

Understanding the reasons behind this shift—and navigating the transition effectively—requires careful consideration. Whether making an MPLS migration to SD-WAN or migrating from SD-WAN to SD-WAN, it’s important to understand concepts like the distinction between overlay and underlay networks and when MPLS should remain part of your strategy.

Why Enterprises Are Making The MPLS Migration to SD-WAN

SD-WAN adoption is catapulting these businesses into the twenty-first century, thanks to its cost-effective solutions. When enterprises adopt these solutions early in the game, they’re better positioned to stay competitive.

MPLS uses predetermined labels rather than network addresses to route traffic. They offer predictable performance and strong Service Level Agreements (SLAs). However, MPLS networks face limitations in flexibility, scalability, cost-efficiency, and adaptability to cloud-based applications.

SD-WAN (Software Defined Wide Area Networking) technology emerged as a solution, providing enterprises with increased flexibility, easier setup, and better cost management. SD-WAN leverages software-based intelligence to manage traffic dynamically across multiple connectivity types, significantly enhancing agility compared to MPLS.

Key Benefits of SD-WAN Over MPLS

SD-WAN allows enterprises to quickly deploy new locations without being restricted to a single MPLS provider. With SD-WAN, expanding your network involves merely adding an appliance and internet connectivity from any provider. MPLS, on the other hand, often requires costly and time-consuming provider infrastructure expansion.

Traditional MPLS-based WAN architectures struggle with modern cloud-driven traffic patterns, requiring inefficient backhauling. SD-WAN directly addresses this by optimizing cloud application traffic, which significantly improves application performance and user experience.

Cost Efficiency

While SD-WAN isn’t always cheaper than MPLS, its flexibility typically results in cost savings. Enterprises can mix and match connectivity types (dedicated, broadband, LTE) to route non-critical traffic over more affordable links, reducing overall costs compared to MPLS, and ensuring you’re not forced to use a single ISP for each site. 

Internet connectivity is significantly cheaper than MPLS connectivity in most instances, and you’ll only need to cover the cost of your SD-WAN appliance or managed service at each site.

Ease of Administration and Network Insights

Unlike MPLS, which often requires extensive provider interaction for changes, SD-WAN empowers information technology (IT) teams with centralized management through cloud-based dashboards. Enhanced reporting provides granular insights into network performance, allowing proactive management and optimization of resources.

Improved Network Resiliency

SD-WAN’s ability to dynamically route traffic and maintain multiple connectivity options greatly enhances network resiliency. Enterprises can avoid single points of failure inherent to MPLS by leveraging multiple providers and routes, ensuring consistent and stable performance.

What To Know About an MPLS Migration

This section walks through what you need to know when transitioning to SD-WAN in terms of network requirements. It also focuses on how to choose your provider/provider type.

Determine Your Network Requirements

Before kicking off an SD-WAN procurement project, you should have a good idea of your network bandwidth requirements. To estimate your bandwidth requirements, you need to know all of the applications and services you want to put on your SD-WAN overlay and the bandwidth requirements of each. 

These requirements will vary depending on where you are accessing your applications from: public cloud, private cloud, or locally. You also need to take into account what your users are doing on those applications, what the application use cases are, when they are being used, and how often.

Estimating bandwidth needs is both an art and a science. The general rule we follow is based on determining if your network utilizes primarily “low bandwidth activities” (such as internet browsing or emailing) or “high bandwidth activities” (such as large file downloads/uploads and video calling). 

Here’s an example:

For low-bandwidth small businesses with, say, 20 employees, simply multiply the number of user devices (let’s assume three devices per employee) by 3Mbps to give you an estimate of required bandwidth. 

In other words, 20x3 = 60 devices. Multiply that by 3 Mbps gives you get 180Mbps, and you would round that up to 200Mbps.

For high-bandwidth businesses, multiply the number of user devices by 10Mbps. For example, 30 users x 3 devices per user = 90 devices. Multiply that by 10Mbps = 900Mbps, rounded up to 1000Mbps or 1Gbps.

Note that SD-WAN appliance bandwidth needs often take into consideration your primary and your secondary circuit. I.e., if you have 100 Mbps DIA primary circuit and a 500 Mbps best effort secondary circuit, the SD-WAN provider will likely charge you for 600 Mbps of throughput.

Understand QoS from QoE

Before signing up for SD-WAN, you need to understand the difference between QoS and QoE. You also need to understand why it matters.

MPLS & Quality of Service (QoS)

To ensure the optimum service availability and transmission quality, the telecom provider deploys a set of technologies that manage network resources to minimize packet loss, latency, and jitter. This is referred to as Quality of Service (QoS). 

Carriers typically provide MPLS service level agreements (SLAs) of at least 99.9% to guarantee they deliver on these QoS commitments of speed, bandwidth, reliability, and performance.

SD-WAN & Quality of Experience (QoE)

Quality of Experience (QoE) refers to the rules set by the SD-WAN network administrator to prioritize and selectively route ingress and egress traffic during times of network congestion. QoE is NOT a guarantee of network performance and is not contractually backed.

In summary, the QoS + SLA guarantees that come with MPLS are more iron-clad than the QoE you receive with SD-WAN. That said, there are a few things you can do to create an SD-WAN that is just as resilient:

• First and foremost, you can build your SD-WAN with a mix of dedicated and best effort circuits to help avoid public internet network congestion.

• You can work with an SD-WAN provider who offers their own “middle mile network” which gives them full control over routing and traffic prioritization between all nodes on a WAN.

• Going one step further, you can choose an SD-WAN provider who will manage your underlay network as well, which reduces the headache of network management and (should) reduce network downtime.

It may take a little extra consideration, but it’s still possible to create a robust SD-WAN network.

SD-WAN Appliance Considerations

Before diving in with an SD-WAN provider, you’ll need to assess their appliance capabilities. Every SD-WAN appliance or “edge device” has its own unique set of capabilities. The key things to consider are:

• How many WAN interfaces does the device have?

• What is the throughput/bandwidth capacity?

• Does it have redundant power supplies?

• Can you stack the devices for high availability?

You’ll need to determine your appliance needs at each location and then make sure that the provider can meet those needs. Ideally, they have a solution that can handle your current and future network needs as you grow.

Choose an SD-WAN Provider Type

As mentioned previously, you can procure SD-WAN on a managed or unmanaged basis. With managed SD-WAN, it’s important to understand that the definition of “managed” will vary by provider.

While some managed SD-WAN providers will manage your underlay network, others will not. This means that if there is an issue with your underlying circuit, the SD-WAN provider who manages your underlay network is responsible for communicating with the network provider to troubleshoot and resolve the issue. 

If your SD-WAN provider does not manage the underlay network, then it’s up to your IT team to troubleshoot and resolve any underlay network issues.

Additionally, the demarcation point between what the managed SD-WAN provider is responsible for and what your IT team is responsible for can vary between providers. Some managed SD-WAN providers will manage your VPNs while other providers will not (but for the most part, “managed SD-WAN” includes VPN management).

Lastly, some managed SD-WAN providers will help you manage circuit Move/Add/Change/Disconnect (MACD) requests, while some providers will not include MACD requests in their definition of “managed SD-WAN.”

Middle Mile Networks

When choosing a managed SD-WAN provider, it’s important to know whether or not they provide a middle mile network and how well-peered it is, if so.

The middle mile refers to the network connection between the last mile and the public Internet. The middle mile network is when the managed SD-WAN provider owns and manages their own points of presence (POPs), direct cloud connectivity, and peering relationships into the public Internet. Peering is when one internet network connects directly to another, enabling a faster throughput and exchange of information without having to pay a third party to carry traffic across the Internet.

If your SD-WAN provider has a middle-mile network, you will send all of your traffic to their network, and they will move it for you. 

For example, instead of you connecting to the Microsoft Azure cloud over the public Internet, you send traffic to your provider and they connect to Azure on your behalf.

Priority Application Peering

When procuring managed SD-WAN, you should have a list of your most business-critical applications/clouds and choose a provider that is well-peered to those applications/clouds via their middle-mile network or otherwise.

This is especially important if you utilize voice applications that are in the cloud given how sensitive voice traffic is to network issues such as packet loss, jitter, and latency.

One useful tool for this is PeeringDB. PeeringDB is an open-source database that lets you check how well-peered SD-WAN providers are. 

Consider the following example:

Cato Networks is a well-peered managed SD-WAN provider. However, you should not rely solely on PeeringDB; do your own research on these peering relationships with the actual provider (Cato even has a contact email for peering on their page).

Underlay Network Management

As previously described in the “Define Managed” section, some SD-WAN providers will manage your underlay circuits for you, and others will not.

This means that if there is an issue with your underlying circuit, the SD-WAN provider who manages your underlay network is responsible for communicating with the network provider to troubleshoot and resolve the issue. If your SD-WAN provider does not manage the underlay network, then it’s up to your IT team to troubleshoot and resolve any underlay network issues.

Edge Security or Not?

While MPLS comes out of the box as a more secure WAN solution, SD-WAN has the potential to make security easily configurable and highly customizable (depending on your vendor). Different SD-WAN vendors offer different types of security options, so you should make your needs clear up front.

Secure access service edge (SASE) combines network security functions (such as SWG, CASB, FWaaS and ZTNA) with SD-WAN capabilities to support the dynamic secure access needs of organizations.

Overlay Versus Underlay Network Considerations

Businesses need to understand the distinction between overlay and underlay networks. This is important for successful SD-WAN deployment.

Underlay Network

The underlay refers to the physical infrastructure—such as internet circuits or dedicated connections—that supports and carries your SD-WAN traffic. Managing your underlay effectively involves ensuring diverse connectivity from multiple internet service providers (ISPs), establishing standardized connectivity tiers.

It may also include leveraging existing MPLS circuits for applications requiring guaranteed quality.

Standardized tiers simplify managing underlay across multiple sites, ranging from robust, dedicated fiber connectivity at critical locations to affordable broadband or Long-Term Evolution (LTE) connections at satellite offices.

Overlay Network

The SD-WAN overlay is the software-defined layer that manages traffic flow and policies independently of the physical network infrastructure. SD-WAN appliances, deployed at each site, establish virtual private network (VPN) tunnels, allowing intelligent, centralized traffic management.

Overlay networks typically fall into three categories:

• On-premises only: Suitable for networks without significant cloud reliance.

• Cloud gateways: These offer improved cloud connectivity via SD-WAN provider gateways.

• Cloud gateways + middle mile network: Provide MPLS-like performance with secure, reliable, and predictable traffic management.

Choosing the appropriate overlay type depends on your enterprise’s reliance on cloud services, scalability needs, and security requirements.

When Should MPLS Be Maintained During an SD-WAN Transition?

While SD-WAN offers numerous advantages, completely abandoning MPLS isn’t always feasible or advisable. Several scenarios necessitate maintaining MPLS alongside SD-WAN:

• Highly Sensitive and Classified Data: Organizations dealing with classified or highly sensitive information, such as government contractors, often retain MPLS to guarantee secure data transmission independent of the public Internet.

• Low-Latency Critical Applications: Financial institutions or real-time data centers that demand ultra-low latency, minimal packet loss, and jitter-free connections may benefit from MPLS’s consistent and guaranteed performance alongside an SD-WAN infrastructure.

• Contractual Obligations and High-Security Requirements: Enterprises with existing MPLS contracts or stringent regulatory compliance needs, such as healthcare or government sectors, may choose to integrate SD-WAN gradually while maintaining MPLS as a secure, compliant network backbone.

SD-WAN to SD-WAN Migration Considerations

As SD-WAN matures, enterprises that adopted early versions may consider migrating to newer, advanced SD-WAN platforms. Strategies for SD-WAN-to-SD-WAN migration include:

• Staged site-by-site migration: This minimizes disruption by gradually migrating each location.

• Parallel SD-WAN deployment: Activating new SD-WAN alongside the old service over existing circuits, ideal when maintaining ISP continuity.

• Simultaneous multi-site migration: A complete transition at once, suitable for comprehensive network upgrades.

Each method presents unique administrative and financial considerations, and the choice depends on enterprise-specific needs, infrastructure complexity, and operational constraints.

Action Plan for Transitioning to SD-WAN

Document existing network topology, subnets, gateways, critical applications, cloud and corporate resources, and internet sources. Comprehensive documentation streamlines the transition process and minimizes potential issues.

A good transition must be organized and purposeful. For that reason, it’s important to begin with a methodical planning and documentation stage.

Documentation and Planning

Documentation and planning are instrumental to any successful network migration. This holds especially true with an MPLS migration. Here are the critical items to document:

• Overall network topology

• Subnets at each location

• Default gateways

• Dynamic Host Configuration Protocol (DHCP) scope/reservations

• Business-critical applications

• Internet source and Internet Protocols (IPs)

• Cloud-hosted applications (and the location of those clouds/applications)

• Corporate-hosted applications

Once you have all your ducks in a row, you can begin to do the math to figure out if SD-WAN is actually a good idea for your enterprise.

Proof of Concept

Conduct a proof of concept (PoC) by migrating a single site initially and testing performance thoroughly to validate the SD-WAN configuration. A successful PoC helps validate the transition approach and fine-tune it before broader deployment.

A few key elements to prepare for the PoC step:

• Select appropriate SD-WAN equipment for your business needs.

• Determine if you have the relevant experience on staff to deploy the equipment and network elements in-house, or select an experienced partner to assist with the SD-WAN deployment.

• Install internet services at the selected site(s). In order to realize a few of the core benefits of SD-WAN, internet services should be ordered and delivered by two or more ISPs.

• Find the appropriate place to bridge the existing corporate resources and MPLS network with the SD-WAN PoC network.

• Before making physical connections and changing routing, most businesses have mandated days and times for maintenance (aka maintenance windows). This step is best suited to take place during a maintenance window.

• During a maintenance window, migrate the PoC site over to SD-WAN.

Implementation and Transition

Depending on your chosen migration strategy, SD-WAN can be deployed gradually or simultaneously across sites. When integrating, ensure network resiliency by maintaining dual connectivity options during the transition—particularly in critical locations.

After thoroughly testing the SD-WAN network to verify that routing, applications, and end-user experience are working and acceptable, you can move through the network one site at a time, or schedule a time to move all sites during a major cutover event.

One other aspect to consider is that there are SD-WAN equipment manufacturers and topologies that are designed to accommodate BOTH internet and MPLS connections.

If your business requires MPLS as a network element, there is an option for a hybrid network.

Building a Strategic Roadmap for Transition

As businesses explore an MPLS migration, they need to understand that it’s not just about installing new equipment. The bulk of successful enterprises begin with a strategic roadmap that aligns technical upgrades with crucial business goals. On average, you can expect this type of roadmap to focus on four components.

Assessment

The first thing you’ll need to do is audit your existing WAN. 

Examine its applications: which are the most critical to your mission? Do any of your sites experience issues with congestion or latency? Additionally, are there any contracts that are expiring soon?

When you focus on a readiness assessment, you can determine whether you’d be best suited to a phased approach or a rapid cutover.

Design

Businesses are encouraged to determine which overlay model is best for their specific needs. This might be:

• On-premises

• Cloud gateways

• Cloud gateways with middle-mile networks

During the design phase, businesses determine if they need MPLS for certain workloads. If, for example, you have a trading floor, then MPLS might be required for any branch offices as they shift to SD-WAN.

Pilot Testing

Before an enterprise can even consider any type of broad rollout, they have to run what’s called a proof of concept through pilot testing. This is conducted at a single site. The goal is to minimize disruption while offering businesses real performance data.

This is advantageous when tracking items such as:

• Jitter

• Failover times

• SaaS application performance

Deployment and Optimization

If enterprises prefer, they may choose to go one site at a time. This is called a staged migration. 

They can also invest in parallel deployments or simultaneous cutovers. Keep in mind that no matter what you choose, each option comes with pros and cons.

The overall benefit is centralized analytics and monitoring. After everything has been optimized, IT teams are encouraged to use dashboards that allow them to refine traffic policies on a continuous basis.

It’s important to remember that this roadmap isn’t just about technology—it’s also about the people who operate it. This includes stakeholder buy-in from finance, compliance, and end users. With a MPLS migration, you want to focus on it not just being a network refresher, but a business transformation.

Cost Modeling and ROI of SD-WAN

In many instances, cost savings are cited by enterprises as one of the largest SD-WAN adoption motivators. However, the math is often skewed. 

Yes, internet bandwidth is cheaper than MPLS circuits. Conversely, it can’t be ignored that migration comes with plenty of its own costs. This includes:

• Appliances

• Licensing

• Managed service fees

• Training

Whenever you create a cost model, you have to focus on three main categories.

Connectivity Costs

It’s common for MPLS pricing to exceed both broadband and internet DIA. The cost difference is often significant. 

With businesses that choose SD-WAN, the benefit is being able to mix connection types. For example, if an enterprise needs to handle non-critical traffic, they can use broadband or LTE. On the other hand, mission-critical apps can rely on DIA.

Operational Efficiency

One of the main drawbacks of MPLS changes is carrier intervention. This is known for creating delays and adding fees. 

With SD-WAN, IT teams can instead focus on centralized dashboards. The result is a decrease in how long network management tasks take and a reduction in overall expenses.

Business Agility

Businesses looking for quicker revenue should keep in mind that opening new locations with SD-WAN is often faster. They won’t be burdened with waiting weeks or months for an MPLS circuit. Instead, a new branch can be online in just days.

Next, enterprises must focus on return on investment (ROI) calculations. ROI doesn’t just account for direct line-item savings—it’s also measured in opportunity cost. 

When a business experiences reduced downtime, faster cloud adoption, and improved support for remote workers, the value is often immeasurable. No, it won’t always show up as direct savings, but in the long run, businesses come out ahead.

Industry Use Cases for SD-WAN Adoption

No matter what type of enterprise you’re running, you undoubtedly have unique reasons for a MPLS migration. To put your business needs into perspective, consider the following industries and how they stand out in SD-WAN adoption.

Retail

Consider chain stores with hundreds of storefronts. Since SD-WAN can improve the performance of cloud-based point-of-sale systems, these chains benefit from rapid site deployment.

Manufacturing

Plants with global facilities rely on visibility. By adopting SD-WAN with centralized dashboards, they gain detailed insights into how each plant performs across the supply chain.

Healthcare

Electronic health records and telemedicine both require the highest levels of security and performance. This is why many healthcare providers are turning to hybrid networks. They benefit from MPLS security protocols to protect sensitive data, while SD-WAN supports general applications.

Finance

Trading firms and banks depend on ultra-low latency for their core systems. However, SD-WAN is ideal for lowering costs across call centers and at individual branches.

Education

School districts and universities support hybrid education through both remote learning and on-campus instruction. When these institutions adopt SD-WAN, it helps ensure smoother virtual lectures and stable connectivity during peak hours.

When businesses transition from MPLS to SD-WAN, the process isn’t one-size-fits-all. It’s unique to each organization’s needs. This is why enterprises must weigh the pros and cons and choose a model that aligns with their sector while balancing cost and overall performance.

An MPLS migration to SD-WAN or upgrading between SD-WAN solutions requires careful consideration of network requirements, overlay and underlay strategies, and scenarios where MPLS remains beneficial. You should thoroughly assess your enterprise’s specific needs, infrastructure complexity, and security requirements to ensure a smooth and successful migration to SD-WAN, maximizing both performance and cost efficiency.

FAQs

How do I know if my organization is ready for migration?

Each enterprise must focus on its specific network profile. You’ll need to consider whether your cloud adoption is growing, as this can help you decide if your business is ready for migration. 

Are your MPLS circuits slow? Are they expensive? 

You also need to factor in whether your locations are expanding. If so, then you may want to consider adopting SD-WAN. The best way to determine readiness is with a network audit.

What mistakes should we avoid?

For starters, never skip proof of concept testing or end-user experience feedback. Additionally, always keep your finance and compliance teams looped in. 

The biggest mistake is assuming that migration is only a technical task. It’s not—it’s an operational shift that involves multiple teams.

Will SD-WAN eliminate MPLS?

The answer is no, not entirely. Certain business sectors, especially those with sensitive workloads, will still need MPLS. 

Keep in mind, though, that MPLS use cases will continue to shrink. As this occurs, SD-WAN will become the primary driver of general business traffic.

Is SD-WAN always cheaper?

Traditionally, broadband is less expensive than MPLS. But businesses must also factor in staffing, services, and appliances as part of the total cost. 

What really controls ROI for SD-WAN is flexibility. That’s where organizations save the most money.

How secure is SD-WAN compared to MPLS?

MPLS is private, but it’s not without limits. SD-WAN can be just as secure. 

What matters is how it’s configured. This includes integrating SASE, firewalls, and encryption. Security ultimately depends on the provider and the technology stack they support.

What about QoS vs. QoE?

In the case of MPLS, businesses are guaranteed quality of service (QoS) through contractual SLAs. SD-WAN, however, relies on quality of experience (QoE), which must be configured by administrators. With smart policies and diverse circuits, SD-WAN can outperform MPLS.

How long will migration take?

The length of migration depends on the size of the firm. Small firms may finish in a matter of months. Large enterprises can take one to two years. 

Timelines vary based on provider contracts, migration strategy, and the number of sites requiring transition.

What is the “middle mile,” and why does it matter?

Each provider has infrastructure that connects your sites to the broader Internet. This infrastructure is known as the middle mile. If you’re looking for more consistent performance—especially for cloud apps—you’ll want a provider with robust middle-mile networks.

Should we choose managed or unmanaged SD-WAN?

If you have a small IT team or lack deep networking expertise, managed SD-WAN is the safer choice. Unmanaged SD-WAN offers more flexibility but is more demanding and resource-intensive.

Which industries benefit the most?

Several industries see strong gains, including retail, healthcare, and manufacturing. Finance and education also benefit significantly.

What are the performance risks?

Performance risks include lack of redundancy, misconfigured policies, and ISP outages. Fortunately, these can be mitigated with continuous monitoring and by relying on multiple providers.

How do we train staff?

Many vendors offer training packages for businesses. These typically teach IT teams how to use dashboards and prepare employees for expected changes in user experience.

What if we already deployed SD-WAN and need to upgrade?

It’s common for businesses to migrate from one SD-WAN solution to another. If your business is upgrading, you can transition site by site or through parallel deployments. The right choice depends on scale and complexity.

How do MPLS and SD-WAN compare for scalability?

MPLS is known for scaling slowly and at a higher cost. SD-WAN, on the other hand, scales quickly with internet connections and is more affordable. For businesses focused on growth, SD-WAN is the stronger option.

What’s next after SD-WAN?

After SD-WAN comes Secure Access Service Edge (SASE). This model merges networking and security into a single cloud service. Enterprises currently adopting SD-WAN will be better positioned to transition to SASE in the future.

Unlocking the Value of MPLS Migration

MPLS migration to SD-WAN is more than a business upgrade. If you’re looking to thrive as a 21st-century enterprise, you need to plan your move accordingly. You’ll not only save money, but you’ll gain agility in an ever-evolving industry while adopting cloud readiness. 

Just as important, the right approach to an MPLS migration ensures security and stability without unnecessary downtime—a major hindrance to both your business and your team. That’s where Lightyear comes in. Our dedicated team simplifies the entire process with data-driven insights and vendor-neutral guidance, giving your business the best-fit solution. 

Schedule a demo today.