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Software-defined wide-area networking (SD-WAN) and multiprotocol label switching (MPLS) are both technologies on the highest level of the enterprise networking hierarchy. While the former is fairly new - rising to prominence in the late 2010s - and the latter first came on the scene about 20 years ago, each of these networking tools can efficiently and effectively handle traffic at the scale demanded by the largest multinational or global organizations.
While some in recent years have seemingly decided that SD-WAN is superior to MPLS across the board, this is not necessarily true in all situations. Our latest Techtorial examines these networking solutions - how they differ from each other, their advantages and disadvantages, optimal applications for both tools, and more.
The first and most obvious factor that differentiates SD-WAN from MPLS is right there in the former's name: While small, router-like devices are often used to help direct the traffic and signals traveling over a virtualized SD-WAN network, its key strengths are in the software at its core. By contrast, the success of an MPLS solution is contingent in large part on the hardware and infrastructure supporting it.
Think of it this way: SD-WAN effectively functions as a virtual private network (VPN) overlay atop one or more networks. As we will see later, that one system can easily be MPLS. It may also be a combination of several different network types, including standard broadband, LTE, 4G (and eventually 5G), ethernet and others.
An MPLS solution can stand on its own and offer efficient management of high-volume network traffic with fairly guaranteed quality of service and considerable privacy. SD-WAN does not function on its own in this manner - but it can make less expensive broadband networking much better, and an advantage like that will always be attractive for many.
The impact of MPLS, upon its debut in the late 1990s (after more than a decade of development), cannot be overstated. It was the first large-scale enterprise networking solution that could offer truly private VPNs – but even more importantly, its use of revolutionary packet-forwarding and -labeling technologies allowed it to direct network traffic with greater speed, quality and efficiency than frame relay and its other predecessors. (For a meticulously detailed explanation of the labeling protocols in MPLS, see the Internet Engineering Task Force's original document on the subject.)
MPLS is arguably best known and appreciated for its reliability. Customers who choose MPLS know they can count on providers to stick to the terms of their service-level agreements (SLAs) and maintain a high quality of service (QoS), as well as packet delivery and strong latency, even with rapidly fluctuating traffic demands across networks that span multiple countries or continents.
Networks on college campuses, metropolitan area ethernet setups and cloud providers handling a great deal of private traffic represent prominent examples of MPLS use cases. But most large organizations requiring a guaranteed high QoS can benefit significantly from this network type. In the arena of enterprise networking, which can often be distinguished by unpredictability and sometimes by outright chaos, MPLS is eminently dependable.
MPLS's longevity in its field is remarkable, particularly given how fast things move in telecom and how quickly products and methodologies can become obsolete. But if it were perfect, there would be no competition for its market share, and it wouldn't be necessary to address needs that SD-WAN can meet more effectively than MPLS alone.
SD-WAN's inherent nature as a virtual overlay that streamlines and accelerates the traffic coming through different networks makes it much more flexible than an MPLS solution can be on its own - particularly in terms of scalability. For example, if a business ever needs to reduce or increase the scope of its MPLS architecture, it can be expensive and difficult to do so. Cost is one of the biggest motivating factors behind the decision of some organizations to move away from MPLS-only networking structures and moving toward SD-WAN.
The ability of SD-WAN to juggle multiple networks also means it can route traffic appropriately through them, based on which connections are functioning most effectively or according to the needs of network administrators and end users, through dynamic path selection. This allows admins to perform "application steering" - prioritizing certain network applications and their traffic over others according to which are most urgent and which can be put on the back burner at any given time. As is the case with its scalability, SD-WAN's flexibility comes at a lower financial and resource cost than trying to accomplish the same things with standalone MPLS.
Furthermore, SD-WAN addresses the need for total control over traffic and bandwidth more effectively than other networking solutions. Admins have unfettered oversight of traffic patterns, and can also amass data about these trends in real time for later use in various network optimization efforts. They can also respond more quickly when problems arise for users, which boosts customer satisfaction.
Lastly, the built-in data protection offered by SD-WAN means it provides greater overall security than what MPLS - despite its value as a reliable carrier of private cloud traffic - can manage.
This is a complicated question to say the least. But it's easy to understand why company leaders and IT or telecom professionals are asking it. The answer is that SD-WAN may eventually replace MPLS, but it won't do so in the immediate future, and not necessarily even in the next five to 10 years.
Why not? Primarily because organizations that have used MPLS for years seem to have developed an "if it ain't broke, don't fix it" mentality. In fact, the vast majority of MPLS customers plan to either expand or significantly increase their infrastructure during the next several years - though plans can always change, especially in the tech world.
There are certain areas where SD-WAN has replaced MPLS. Retail is easily the most notable example of this, as the former's capacity for dynamic path selection is so critical to handling high-volume traffic from transactions. Health care and finance are also migrating to SD-WAN with considerable frequency. But even if SD-WAN were to phase out MPLS, certain technologies are already viewed by some as replacements for the former: Secure Access Service Edge (SASE), a cloud-based, distributed architecture networking method, is the most likely candidate to be considered "the next big thing" in enterprise telecom.
While not the case in every situation, the answer to this question is certainly "yes" more often than "no."
By keeping MPLS infrastructure in place and adding SD-WAN on top of it (and perhaps some lower-level broadband options as backup if these are not already there), you have all the dependability of MPLS while also giving yourself greater network control. Steering your traffic as dynamically and efficiently as possible for your organization benefits you and your customers alike.
GTT Communications has the expertise, breadth of services and ingenuity to help you choose the best enterprise telecom solution for your networking needs, be it SD-WAN overlaid on broadband, SD-WAN with MPLS, MPLS alone or another WAN method. To learn more, get in touch with us!