Most IT managers are faced with the dilemma of choosing from MPLS or SD-WAN as both the technologies come with their own set of pros and cons. While many people were claiming that the internet is the future of WAN networks like all other things, there are some inherent strengths of MPLS network that cannot be ignored. Our analysis of MPLS leads to four key areas that include- network security offered through isolation, carrier managed site-to-site connectivity, availability and delivery of the reliable packet, and the quality of service offered.
Apart from these key areas, IT managers need to take into account the price, performance and practical impact of the network too before making a final decision. Let us compare both networks by evaluating these crucial aspects:
Comparing Reliability and Availability of Packet Delivery
MPLS has always been regarded as more reliable in terms of packet delivery and this has been its biggest USP. It implies that MPLS is less susceptible to packet loss allowing you to meet real-time protocols like virtual desktops, VoIP and video conferencing without any substantial loss of quality. Since MPLS networks are largely shared infrastructures, issues of packages being dropped may arise due to congestion as multiple users are competing for bandwidth and router processing. However, the drop rate in MPLS network is around 0.1% to 1% while the Internet is likely to experience packet loss of more than 1% or so. To offer additional security, MPLS providers sign a Service Level Agreement for the percentage of packets that might be dropped during a given period while there is no such provision in case of Internet connections since it is an unmanaged network without any SLAs.
Your MPLS provider is most likely to provide you with a COS/QOS bucket where you can put critical traffic to ensure its delivery on high priority basis. In a case of SD-WAN, there is no QOS for crucial traffic and hence no guarantee of packet delivery. However, total Internet blackouts are a rare occurrence owing to the density of interconnections. Intermittent slowdowns are more common phenomena that can be taken care of by choosing two Internet links from two different providers.
Providing you take varied paths onto the Internet, this will ensure 99.99% availability of packet. You can measure per-packet loss for each link and choose the one that has a minimal loss, redirecting all traffic to that link. These days Forward Error Correction tools are also available to rescue that lost data by rebuilding the lost packet. FEC ensures consistent delivery of the packets irrespective of the losses on a particular WAN link.
Comparing Prices- Which One Allows Lower Costs?
MPLS is a bit on the pricier side with business users paying even twice or thrice the price for a network as compared to their Internet DSL. In fact, a survey by Telegeography indicated that Internet bandwidth could be 90 percent lower than that of MPLS. The cost, however, also depends on the COS of MPLS provider. But there is always a provision of discounts and other leverages offered by the MPLS services which bring the difference to as close as 30%. We would not say that the difference of thirty percent is not significant but the savings you incur with SD-WAN do come with their own baggage.
Analyzing Security of SD-WAN and MPLS
With unique labels attached to the packets, IT managers have always considered MPLS to be more secure. Owing to the unique labels, only MPLS nodes looking at that tag are in a position to read the packets while there is no such provision in case of an internet based service. You need a strong protocol like IPSec and additional firewalls to secure the traffic on SD-WAN. There have been indications of MPLS carriers sharing data with the government. Also, the data sent around such networks is not encrypted until you decide to do so yourself. When it comes to SD-WAN, you can always establish VPNs across the internet. So, the organizations looking for an additional level of security should choose MPLS but for most organizations, VP security is certainly more than enough.
Is Connectivity from Site-to-Site a Game Changer?
Many IT managers have over the years relied on MPLS for site-to-site connectivity owing to the simplicity of the connection, as everything from line delivery to parameter configuration is handled by the service provider. If we talk about the internet, the process is a bit complex because the onus of configuration lies with your IT department.
However, SD-WAN is much quicker than MPLS services. The IT department needs to place a network device at the remote site and connect it to the existing VPN infrastructure. Then a simple configuration of other sites is required to communicate with the device. This process can either be manual or automated and comes with implicit security. As we have already discussed that provisioning an MPLS line does not take into account all the security measures.
A Quick Glance at the Performance of MPLS and SD-WAN
MPLS is accredited with lower latency and packet loss and better uptimes because it is a managed service. The routing policies are designed for maximum performance and all performance attributes are backed with SLAs. There is less strife for backbone bandwidth as MPLS service has a lower over-subscription ratio in the access layer as compared to an Internet service.
SD-WAN lacks Service Level Agreements and management but the performance of Internet backbone performance has witnessed an upswing due to shift to fiber and more undersea cables in the past few years. Still, spikes in a loss in cases of local loop performance are common in SD-WAN connections. Moreover, internet routing is designed as per the business requirements of the service provider which may not necessarily align with customer requirements.
Final Thoughts. . .
Businesses today need agile systems that deliver prompt results with an increased level of efficiency. Considering this, internet with SD-WAN has a definitive advantage over MPLS because it is faster, globally available and can be accessed at a tenth of MPLS costs. If you have made up your mind to choose Internet and SD-WAN, do ensure to invest in a symmetric Internet connection in order to simplify the setup of QOS. To avoid congestion it is advisable to order two lines from two different Internet providers. For running real-time protocols like voice, video or VDI, make sure that there is ample provision for avoiding packet loss and VPN and encryption are built-in. SD-WAN can also assist in making some considerable CAPEX savings by swapping all equipment present in your branches for a single appliance. However, it is too early to say that SD-WAN is the perfect MPLS substitute since it is still in a very early adopter’s phase.