We are frequently asked what sounds like a simple question by customers, partners, and even Nitel employees: will SD-WAN replace MPLS for business private data networking? There are many opinions on this topic, but let’s look at some facts. According to a recent study,* 29% of IT leaders indicated that their companies have deployed or are considering deploying SD-WAN in the next 12 months. However, 62% of those IT leaders report their MPLS investment will increase or remain unchanged over the next couple of years. The move towards software defined networking is undeniable, and while we anticipate more growth in adoption rates over the next few years, MPLS isn’t going anywhere anytime soon. Why? We’ll take a closer look at the features of MPLS and SD-WAN that make each technology a valid solution depending on the situation. To provide a framework for this discussion let’s make two assumptions:

  1. The MPLS network is being provided by a single service provider over a carrier grade private network with typical service level agreements.
  2. The SD-WAN is being provided over two Internet circuits, one a carrier grade dedicated Internet service and the other a cable broadband service.

Packet Delivery
The right SD-WAN solution using the right configuration can provide packet delivery performance similar to that of MPLS. While a carrier grade MPLS network will offer packet delivery in the 99.9% range, SD-WAN can use methods to mitigate packet loss on Internet access links, depending on the provider and underlying technology. For example, forward error correction is a function of some SD-WAN solutions that adds parity bits to packets and injects parity packets in the packet flow, allowing the receiving SD-WAN node to recover lost packets. With the right SD-WAN solution that is designed correctly, you can have the same packet delivery performance as MPLS.

Application Prioritization & Performance
One of the key benefits of a private network is the ability to prioritize applications over shared network resources, to ensure the most important applications perform as expected all the time. The right SD-WAN solution can simplify the task of prioritizing applications and managing their performance, but MPLS delivers more certainty regarding high priority application performance. When an SD-WAN network prioritizes applications to be carried over the Internet, there is no guarantee that the Internet will honor the prioritization desired. The packets will be prioritized when they leave one end, but they are subject to the world wide wild web as they travel to the far end. On an MPLS network, the QoS is honored across the entire network, so what is prioritized on one end stays prioritized across the network to the far end.  IT professionals like the predictability and reliability when it comes to MPLS.


With two Internet access links, assuming they are from different providers, SD-WAN offers a simple and powerful way to improve reliability. A single MPLS access link is much more likely to experience an outage, but not because of any characteristic of MPLS that makes it inherently less reliable. Rather, when your traffic uses a single link, your business is at the mercy of that one circuit. If it goes down, you go down. Many businesses back up their MPLS networks using a failover solution to an Internet connection using BGP, and a VPN to regain access to the private network. But why would you want to pay for backups that may not have much other use? The SD-WAN solution relies on two fully-active Internet connections and is aware of the quality of both paths at all times. As a result, high priority applications can be routed over the best available path at any moment, including the moment one of the access links fails. Depending on the SD-WAN solution design, even a phone call will not be interrupted.


MPLS networks are inherently very secure. The network itself doesn’t even touch the public Internet. Or, in engineering terms, only MPLS nodes that are reading the packet labels destined for that node can see the content of the packets. Now, every business needs to access the internet. And where it does, security has to be considered. But MPLS, by itself, is very secure. Because SD-WAN uses the Internet to route private traffic, businesses must incorporate network security over the top to fend off threats. Fortunately, SD-WAN solutions such as Nitel’s offer integrated next-generation security with unified threat management that uses the same appliance, analytics and control panel as the SD-WAN solution. This provides security at each location on the WAN while providing a scalable control, analytics and reporting platform for the network administrator.


All companies and industries have different needs, compliancy issues and requirements. The private nature of an MPLS network might be necessary when dealing with private or proprietary information, for example, at a hospital or a bank. However, for many companies, SD-WAN with a next generation firewall is sufficient. Not sure which is the best fit for your customer? Reach out to one of our experts today to learn more.

Check out the rest of the Guys in Orange videos to learn to learn more on the latest trends.

*According to a study conducted by 451 Research.