Cloud-Based SD-WAN, and the end of the MPLS vs SD-WAN Debate

The industry has seen the SD-WAN vs MPLS (Multiprotocol Label Switching) debate become less and less heated recently. A few years ago, it was common to see proponents of MPLS downplaying SD-WAN and its use cases. Today, industry experts and enterprises alike have recognized that SD-WAN makes much more business sense for most modern applications. Reliability and SLAs were two of the biggest focal points causing enterprises to stick with MPLS in the past, but premium cloud-based SD-WAN providers provide enterprises a solution that meets those requirements as well.

While MPLS still has some use cases, namely reliable routing between a few static physical sites, SD-WAN benefits have led to more and more enterprises making the transition to SD-WAN. Here, we’ll explore the advantages SD-WAN has over MPLS and explain why the vast majority of enterprises are making the leap.

 

MPLS vs SD-WAN appliances

Of course, SD-WAN solutions come in a variety of shapes and sizes. To properly frame the MPLS vs SD-WAN debate, let’s start with using SD-WAN appliances a.k.a. DIY (Do-It-Yourself) SD-WAN. With DIY SD-WAN, organizations could use SD-WAN appliances to bring the benefits of SDN (software defined networking) to the WAN. Flexible routing and the ability to use multiple transport mediums (e.g. DIA, 5G, cable) provided enterprises with a few key benefits relative to MPLS. These benefits included:

• Reduced bandwidth costs. MPLS bandwidth is expensive. With SD-WAN appliances, enterprises can achieve significant savings by using economical public Internet bandwidth.
• Better performance for cloud services. MPLS often necessitated inefficient backhauling for cloud-bound WAN traffic. The inefficiencies of this backhauling and the looping path cloud traffic takes to its destination with MPLS has been dubbed “trombone routing”. With SD-WAN appliances, enterprises had a means to route cloud traffic more efficiently.
• Increased WAN agility. WAN traffic has become more and more dynamic over the past decade. Cloud computing and mobile & remote workforces are now the norm. MPLS simply wasn’t designed for this paradigm. SD-WAN allows enterprises to use different transport methods and policy-based routing (PbR) to keep up with the dynamic data flows.

While these benefits were impressive, they often weren’t enough to compel a complete switch to MPLS. Instead, enterprises would use SD-WAN appliances for cloud workloads and less critical or latency sensitive workloads, but stick with MPLS for high-performance, high-reliability connectivity between sites. Why? Because MPLS offered them an SLA and dependable performance. Switching to SD-WAN and relying solely on Internet transports, even if they were redundant, wasn’t an attractive option.

Enter Cloud-based SD-WAN

To compel a complete shift away from MPLS, enterprises needed a solution that provided the cost-savings, cloud-friendliness, and agility of SD-WAN with reliability and performance that was on par with MPLS. Premium cloud-based SD-WAN does just that.

Inherent to cloud-based SD-WAN are the fundamental SD-WAN benefits of DIY SD-WAN. PbR and the ability to leverage a variety of transport methods are part of cloud-based SD-WAN too. What cloud-based SD-WAN adds is a Service Level Agreement-backed private WAN backbone. The backbone includes Points-of-Presence a.k.a. PoPs across the world. These Points-of-Presence are connected by Tier-1 Internet Service Providers. A private backbone and the benefits cloud-native infrastructure allow premium cloud-based SD-WAN providers to deliver a few additional benefits to enterprises, including:

• Enterprise-grade reliability. The best cloud-based SD-WAN providers can deliver 99.999% uptime SLAs. “Five nines” means enterprises can expect the same reliability from their SD-WAN solution as they did from MPLS.
• Further optimized cloud & mobile performance. We know DIY SD-WAN helped resolve the trombone routing problem. Cloud-based SD-WAN takes that a step further by optimizing for cloud and mobile. In many cases, cloud-based SD-WAN PoPs share datacenter space with major cloud service providers. This allows for connectivity comparable to premium connections like Azure ExpressRoute or AWS Direct Connect without the additional expense. Similarly, the cloud-based nature of the WAN infrastructure means mobile users can connect from anywhere, and mobile clients make doing so simple.
• Simplified WAN management. With both DIY SD-WAN and MPLS, enterprises needed to maintain a variety of additional appliances. These included security appliances and WAN optimizers. The additional appliances required additional maintenance, provisioning, and troubleshooting. While enterprises could offload this to a service provider, doing so wasn’t cheap. With cloud-based SD-WAN, the functionalities provided by these appliances (Next-generation Firewall or Intrusion Prevention Systems for example) are now built into the network. Additionally, cloud-based means patching software and maintaining hardware are no longer a concern.

Cloud-based SD-WAN is ideal for modern networks

The past few years have seen the MPLS vs SD-WAN debate change significantly. No longer is MPLS the only “go to” option for enterprise-grade WAN connectivity. Cloud-based SD-WAN provides enterprises with an alternative that delivers MPLS-level reliability without sacrificing agility or access to affordable bandwidth. Going forward, modern WANs continue to become more complex and dynamic as time marches forward. Trends like BYOD (Bring Your Own Device) and UCaaS (Unified Communications as a Service) will only increase the need for agility and reliability. As a result, the benefits of cloud-based SD-WAN will become more pronounced.