SD-WAN Vs. MPLS: How Do the Two Technologies Compare?
MPLS (Multiprotocol Label Switching) was the go-to WAN connectivity solution through the early 2010s. However, in recent years, MPLS dominance has waned while SD-WAN adoption has grown. In fact, in 2018 Gartner declared that SD-WAN was “killing” MPLS.
While it’s true MPLS is far from dead today, with analysts still predicting moderate growth in MPLS markets for the next few years, it is no longer the de-facto WAN solution. For many enterprises, the costs and inflexibility of MPLS have made SD-WAN a more attractive solution. But what are the specific advantages of SD-WAN? How do you know which solution is best for your use case? Here, we’ll explore SD-WAN vs MPLS in-depth and help you answer those questions.
SD-WAN Vs. MPLS: Bandwidth Costs
MPLS bandwidth is notoriously expensive. In fact, the cost argument is one of the most common made against MPLS. However, it’s worth noting that competition and network upgrades have driven down MPLS bandwidth costs for many regions in recent years. Even with these price cuts, MPLS bandwidth remains significantly more expensive than public Internet bandwidth. It isn’t uncommon to see network cost savings upwards of 25% with SD-WAN.
SD-WAN Vs. MPLS: Reliability
Traditionally, one of the most commonly cited MPLS benefits is reliability. Dedicated MPLS lines come with SLAs (Service Level Agreements) that guarantee a certain level of uptime. SD-WAN appliances are network overlays, and therefore reliability depends on the underlying network services. If we compare a single MPLS link to a single public Internet link, MPLS wins the reliability argument hands-down. However, SD-WAN appliances can use multiple network services, including MPLS, making the topic a bit more nuanced.
In fact, it’s common for SD-WAN appliances to be used in conjunction with MPLS. However, doing so limits an enterprise’s ability to replace MPLS completely. As a result, many enterprises that want the benefits of SD-WAN with the reliability of an MPLS connection are turning to cloud-based SD-WAN providers.
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SD-WAN Vs. MPLS: Performance
When it comes to connecting locations (e.g. headquarters and a branch office), MPLS has been the gold-standard for some time. In a nutshell, this is what MPLS does best.
MPLS provides low-latency connections on a global scale that public Internet-based alternatives (e.g. Internet-based VPN and SD-WAN appliances using only Internet-based network services) simply cannot match. As a result, throughout the early 2000s and 2010s, many enterprises depended on MPLS for interconnecting sites.
In recent years, the availability of cloud-based SD-WAN has changed things. With a global private backbone, cloud-based SD-WAN vendors provide low-latency connections that rival MPLS. This means enterprises now have a viable MPLS alternative to connect physical locations around the world.
Of course, connecting physical WAN locations is only part of the story for modern enterprises. Cloud-computing and mobile users are the norm on modern business networks. With MPLS, enterprises must often backhaul cloud-bound traffic to a single WAN endpoint (e.g. a firewall) for security purposes. This inefficient routing adds latency and degrades performance. The added latency can in turn create issues with business-critical services that are more frequently shifting to the cloud, such as VoIP (Voice over IP), teleconferences, and video streaming. SD-WAN allows enterprises to bypass the backhauling and optimize cloud performance.
Mobile users create a unique challenge for both SD-WAN appliances and MPLS. Securely connecting mobile users and enabling them to access WAN resources is often complex and impractical. Select SD-WAN vendors offer mobile clients that make this process simple. By using these clients, enterprises can provide mobile users with WAN connectivity comparable to on-prem users.
SD-WAN vs MPLS: Agility
Simply put: SD-WAN solutions outstrip MPLS when it comes to agility and flexibility. MPLS wasn’t designed with the dynamic nature of cloud and mobile in mind. SD-WAN on the other hand enables enterprises to abstract away underlying network services and use policy-based routing (PbR) to optimize network performance.
Additionally, cloud-based SD-WAN has been proven to significantly reduce WAN provisioning times. While turning up new sites with MPLS can take weeks or months, the same can be done with cloud-based SD-WAN in days or even hours.
SD-WAN vs MPLS: Security
Encryption isn’t inherent to MPLS. It is considered “secure” because MPLS circuits are dedicated to a single organization and in theory, no one else could sniff the packets traversing the network. While this paradigm works well if traffic only goes back and forth between physical locations within the enterprise, that simply isn’t the case for most businesses today. Public cloud services are ubiquitous, and traffic regularly flows to and from endpoints outside of the WAN. As a result, enterprises must integrate security solutions such as Intrusion Prevention Systems (IPSs), Next-generation Firewalls (NGFWs), anti-malware services, and Secure Web Gateways (SWGs). This adds complexity and room for oversight.
SD-WAN solutions vary as to the level of security that comes built-in. For example, some appliances simply offer SD-WAN functionality, while others include stateful firewall features. In general, the appliance-based approach to SD-WAN often leads to a similar situation to MPLS where additional security appliance must be integrated to the network.
Cloud-based SD-WAN handles security differently by building security into the underlying network backbone. As a result, enterprises are able to limit the need for additional appliances and provide all users that connect to the WAN with secure connectivity “out of the box”.
Final thoughts: Making an informed decision
MPLS isn’t dead, but the use cases where it makes business sense are decreasing. SD-WAN provides enterprises with a more flexible solution than MPLS, particularly when you consider cloud-computing and mobile users. There’s no single WAN connectivity solution that is right for every business, but by understanding the pros and cons of MPLS and SD-WAN, you can make a decision that is best for your business.