Nixon Thuo
Nixon Thuo Consulting Services Solutions Architect

Is SD-WAN really a replacement for MPLS? The question has troubled IT managers, CTOs and network administrators in this era of digital transformation.

Network connectivity has become a major cog in the wheel of digital transformation for organisations seeking to thrive in the digital economy.

There is no doubt that Wide Area Networks (WANs) continue to serve the needs of the distributed enterprise. But with the advent of new network technologies like SD-WAN rivalling MPLS, which technology is best-suited to serve the African enterprise?

To answer this, let’s go back to the basics of WAN connectivity. What is MPLS? Contrary to what you might think, it’s not a service or a type of Internet connection, it’s a technique for interconnecting distributed branches.

The service is a managed Virtual Private Network (VPN) usually routed through the service provider network infrastructure. The main benefit of MPLS is that traffic is routed through a private data network (unlike Internet traffic) which allows the ISP to guarantee a high, end-to-end Quality of Service (QoS) which is usually backed by a binding SLA.

MPLS excels at managing and avoiding packet loss, jitter and latency which introduce predictability to business traffic flows. MPLS can also offer traffic prioritisation, which ensures that your most crucial traffic is handled with the highest priority and the least likelihood of being dropped.

For organisations running real-time applications over the WAN such as VoIP, video conferencing or virtual desktops, MPLS is the holy grail of network connectivity due to its predictability and reliability. MPLS also introduces operational efficiencies for the distributed enterprise with centralised ICT operations where all branch traffic has to be backhauled to the HQ over the WAN.

Now let’s focus on SD-WAN. An abbreviation for Software-Defined networking in a Wide Area Network, it finds its basis in software-defined networking (SDN).

SD-WAN overlays intelligence into traditional WANs by decoupling the underlying hardware and software permitting central network control, traffic management and network automation.

SD-WAN allows enterprises to use several transport services to interconnect the WAN, including broadband Internet, 4G LTE and even MPLS. A VPN will be set up across each WAN connection to establish a multi-connection, multi-transport hybrid WAN infrastructure.

The embedded intelligence allows organisations to build application-aware networks that improve application performance and enhance user experience especially for businesses hosted in the cloud since traffic does not have to be backhauled to the HQ data centre.

SD-WAN can also securely and intelligently direct packets to the best WAN link and improve business productivity. SD-WAN’s advantage is its multi-connection capabilities, which reduce the time and cost of deploying WAN links, especially in remote locations, while avoiding vendor lock-in.

All this sounds great, but which of the two are right for your business? Consider this: Does your business run real-time applications? Does it operate from the cloud?

For real-time applications, SD-WAN overlaid on Internet links might not measure up against MPLS connections because once traffic hits the public Internet, you can’t guarantee low levels of packet loss, latency and jitter.

For businesses running cloud-based applications such as Office365 or Salesforce or for organisations with environments in AWS or Azure, cloud-enabled SD-WAN offers numerous benefits such as dynamic routing and intelligent traffic steering which enhance application performance.

SD-WAN can overlay inter-branch and branch-cloud connectivity with security, achieving end-to-end encryption, and best path selection over the Internet. However, there are no performance guarantees. But if your business has specific connectivity requirements and needs SLA-backed performance guarantees, MPLS might be better suited for the job.

The MPLS vs SD-WAN debate should be held within the contextual boundaries of the environments you’re working in, the network traffic definition and the specific needs of your business.

If your business requires a high-performance and reliable WAN architecture, you should consider a hybrid of both solutions.

Remember that SD-WAN is a transport-agnostic overlay that can route any type of traffic, including MPLS. So away from the hype, is SD-WAN really an MPLS killer? In my opinion, not really.

To discuss your company’s individual needs and what service might best suit you, speak to your enterprise WAN architect.

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