SD-WAN vs. Traditional WAN

What's the difference between the two technologies and which one is best for your business?

Articles published December 13, 2017 by Steve Simpson

worldwide network connection lit up

The switch to a software-defined wide area network (SD-WAN) is becoming an increasingly popular option to businesses worldwide. In fact, the global SD-WAN market is projected to reach $26 billion by 2028, according to Adroit Market Research.

However, leveraging traditional wide area network (WAN) technology is still a valid and reliable way to deliver and receive network services. In some cases, a hybrid approach with both in play can be the most beneficial. It really depends on the needs and unique situation of each organization.

Whether your organization is still relying on Traditional WAN, has switched fully to SD-WAN, or implementing some combination of the two, here’s what you need to know about these two technologies. 

What is Traditional WAN?

Traditional WAN technology has long been the go-to for IT, voice, and data networking infrastructure. Used to connect multiple office locations, a traditional WAN connects local area networks (LANs) to each other through routers and virtual private networks (VPN).

Traditional WANs mostly rely on dedicated multiprotocol label switching (MPLS) connections to provide secure, direct connections for reliable and efficient network traffic flow. This allows you to prioritize the voice, video, and data traffic on your network.

SD-WAN Explained

As business-critical tools and apps have moved online, network traffic has increased, taxing the MPLS connections of a fully traditional WAN. SD-WAN is a unique approach to wide area networking because it combines traditional WAN technologies, like dedicated MPLS, with more cost-effective broadband connections. 

SD-WANs provide organizations with an end-to-end view of the entire WAN, and the ability to prioritize network traffic over different connections. SD-WAN measures traffic and selects the best route for each data packet in real-time. 

With SD-WAN, organizations can connect all of their offices to a central network in the cloud, which can increase control and flexibility.

How does SD-WAN compare to Traditional WAN?

Reliability and Prioritization

Overall, traditional WANs running over MPLS offer great Quality of Service (QoS), since they avoid packet loss by virtually isolating packets. Most of the time, this is run over one carrier-grade circuit connection. One thing to keep in mind though is that MPLS bandwidth like this is typically more expensive.

Determining what traffic gets higher priority is essential, helping organizations ensure their calls aren’t dropped. Traditional WAN technology allows for prioritization and can give you that traffic predictability and reliability.

Research reveals that internet costs can be reduced with SD-WAN. This is due to the fact that you don’t have to pay as much to upgrade your bandwidth, along with the ability to mix and match network links in a cost-effective manner, according to the content type and priority. SD-WAN can run on 4G LTE and internet broadband, which is typically less expensive than service delivered via an MPLS network.

SD-WAN allows you to send your most important data traffic over the best network link, along with dozens of application prioritization options. This leads to little or no latency and packet loss. Additionally, if an outage occurs, your traffic is switched over to another connection instantly.


Traditional WAN is considered quite secure. Over an MPLS connection, packets that are sent are private, and can only be seen by the destined MPLS connection, allowing site-to-site secure communication.

SD-WAN keeps your data traffic secure by providing end-to-end encryption over a virtual private network (VPN) connection. This technology also allows you to easily implement and integrate additional security layers, such as a firewall and related services for unified threat management.

Control and Scalability

When changes to your traditional WAN are needed, it has to be done manually. This can take longer and decrease efficiency for growing businesses—especially those adding branch offices.  

As a software-based solution, it’s relatively simple to scale SD-WAN as your organization grows, especially if you partner with a managed service provider.

SD-WAN vs. Traditional WAN

  • SD-WAN runs on a mix of network connections, which can help reduce cost.
  • SD-WAN offers application prioritization options and sends important data over the best network link.
  • SD-WAN uses encryption & VPN for secure end-to-end network connections
  • SD-WAN is Easy to update and scale SD-WAN
  • Traditional WANs on MPLS offer great QoS, but can be more expensive.
  • Traditional WAN offers reliability and predictability with prioritization of critical traffic like voice & video.
  • Traditional WAN's MPLS connection is very secure
  • Changes to traditional WANs need to be done manually

Ultimately, the decision between traditional WAN and SD-WAN depends on your organization’s situation and current infrastructure. Many organizations are making the switch to SD-WAN, but everyone’s circumstances are different. It comes down to what will be more beneficial for your short-term objectives and long-term needs.

How could SD-WAN benefit your business?

About The Author

Steve Simpson

Steve Simpson is an experienced Client Advisor at Aureon, where he works with business leaders and technical resources to explore new ideas. For the last 30 years, his efforts have been focused on providing technology services in healthcare, manufacturing, banking, state/local government, and sen ... read more

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