When companies expand their networks over long distances, and sometimes across networks with multiple operators, they experience operational problems, including network congestion, packet delay changes, packet loss, and even service outages. Modern applications, such as VoIP calls, video conferencing, media streaming, virtualized applications and desktops, require minimal latency. Bandwidth requirements are also increasing, especially for high-definition video applications. Enhancing WAN capabilities can be costly and difficult with associated network management and troubleshooting difficulties.

The question arises, what is the best way for enterprises to connect multiple locations and users to business-critical resources while balancing performance, reliability and cost?

Over the years and decades, the two most popular wide area network (WAN) connectivity options have been multiprotocol label switching (MPLS) and internet, but in recent years, IT administrators have begun to consider adding a software-defined WAN (SD-WAN) overlay, with the aim of obtaining a deeper understanding on those issues and properly address them.

WHAT IS MPLS?

MPLS is a protocol for accelerating and generating network traffic flows, which, in essence, means the sorting of MPLS and prioritizing your data packets based on their class of service (for example, IP phone, video or Skype data). With MPLS, the available bandwidth is increased, and mission-critical applications such as voice and video guarantee of highest grade.

ADVANTAGES OF MPLS

MPLS works in a similar way that routers and switches do and is used to deliver traffic based on its type, where it’s going and on its priority. MPLS uses predetermined, highly efficient routes through a private network, giving enterprises peace of mind that real-time traffic like video or voice will get to where it needs to go using a low-latency route, something that is difficult to guarantee with traditional routing.

Key benefits of using MPLS include:

  • Reliable packet delivery helps maintain data quality for real-time protocols like voice and video
  • Labels virtually isolate packets and assign higher priority to help provide traffic predictability
  • Suitable for high-performance, distributed networks
  • Independence from the features of data link technologies such as ATM, Frame Relay, SONET / SDH or Ethernet

WHAT IS SD-WAN?

Software Defined Wide Area Network (SD-WAN) is an automated software approach to managing the connection of company branches. It expands software-defined networks (SDNs) into a solution that enterprises can use to quickly create an intelligent hybrid WAN network that includes Internet (either broadband or DIA)

In the past, dedicated MPLS channels were frequently used for security and reliable connection, however, these are no longer suitable for a rapidly growing cloud environment. Nowadays, WANs are struggling to cope with the load of new demanding applications, such as video streaming and database sharing.

Hybrid WAN architectures allow companies to manage a rapidly growing number of applications, especially when using the cloud. Unlike the traditional WAN architecture, the SD-WAN model is designed to fully support applications located in local data centers, public or private clouds, while providing the highest level of application performance.

ADVANTAGES OF SD-WAN

Organizations that are looking for more flexibility to connect to remote networks will find SD-WAN of great benefit.

You may take any number of different connection types and put an SD-WAN service overtop of those in order to help dynamically manage traffic flow. That combination of connection types depends on your application environment and business goals. As it is based on software instead of hardware, you can easily implement, scale and manage SD-WAN in a fraction of the time and cost that it takes for MPLS.

Main benefits of SD-WAN include:

  • Reduced WAN OpEx and CapEx costs, as well as total cost of ownership
  • Support for multiple secure high-performance connections
  • Load balancing between connections and regulating traffic flows depending on network conditions to improve performance
  • Support for the automatic provisioning and change of network services such as VPNs, firewalls, security, WAN optimization, and application delivery control
  • User Initialization Support (ZTP)
  • Improved network security by encrypting WAN traffic and network segmentation to minimize damage in the event of a breach

ISSUES SOLVED BY SD-WAN

In modern realities, traditional WANs cannot provide in full the functions of productivity, flexibility, and also the function of regulating enterprise operating expenses. SD-WAN, on the other hand, increases manoeuvrability and productivity, using the functions of choosing dynamic routing along the optimal path, as well as programmable network devices with remote control. SD-WAN is able to actively respond to network status in real time.

When the SD-WAN is integrated into the edge device, it monitors the status of all public and private services and determines how to properly route each type of application traffic. For example, you can send voice over IP (VoIP) traffic through the MPLS VPN service by default. However, if the MPLS connection becomes overloaded, the SD-WAN can switch this traffic to broadband Internet or 4G LTE wireless network. Thus, SD-WAN provides automatic load balancing and network congestion management for better performance and less costly routing.

SD-WAN vs MPLS

A lot of the people are very quick to jump to the question “should I choose SD-WAN over MPLS?”, or indeed the other way around. The answer is: it’s not quite as simple as that.

Although MPLS is still widely used, many expect the SD-WAN to take over in the future. SD-WAN is applied to standard WAN connections to connect devices over long distances. One of the biggest advantages of SD-WAN over MPLS is its higher performance. SD-WAN uses a combination of MPLS, Internet (broadband or DIA) and LTE to stay connected. Essentially, this creates a hybrid network that can switch between depending on packet rate and real-time network performance. In practice, this leads to better packet delivery.

At the same time, MPLS is not far behind in terms of reliability. This is an efficient package delivery method and provides high quality service. The problem is that MPLS works on a shared network, which often leads to competition for contention competition. This can be a significant cause of congestion compared to SD-WAN.

TENDENCIES: SD-WAN vs MPLS

While SD-WAN certainly has its advantages, implementing it and especially replacing MPLS altogether can be a big challenge for organizations.

Greg Bryan highlights in his Telegeography article, that from the beginning, SD-WAN vendors have pinned SD-WAN to functionally replace MPLS due to the use of adequately diverse underlay connections and there have indeed been numerous cases where companies have mostly or in certain cases – entirely, left MPLS behind.

However, there are also those who have added SD-WAN as an enhancement to their MPLS solution.

This leads to several interesting questions, for example: What are the plans for MPLS in the future and will SD-WAN eclipse MPLS? Would one still need to rely on MPLS once SD-WAN is in place? To answer these, we dug into the WAN Manager Survey 2019 and found some interesting tendencies.

For example, 83% of organizations were at least considering SD-WAN, with 43% already adopted or in the roll-out phase. These numbers are expected to increase for 2020.

Furthermore, the data demonstrated that those who already had SD-WAN installed had fewer sites running MPLS. While the numbers have indeed decreased, it does show that most organizations will start with gradual transitions to SD-WAN from MPL, meaning that the latter is not going to completely go away in the next 2-5 years. After all it is still installed at most sites in most corporate networks, and transitions don’t happen fast.

Furthermore, WAN managers might change their minds about the ability of SD-WAN to truly replace MPLS functionality after they see SD-WAN at work, especially if they have some non-MPLS sites. Though the most likely scenario is that by 2025 MPLS will still be in use where enterprises feel there is a particular need, but as a niche product—a shadow of its former dominant position in the market.

SD-WAN & MPLS: COMPLIMENTARY CONNECTIVITY?

In Govtech’s article, Verizon stated that MPLS is part of the connectivity component when it comes to one’s network and SD-WAN manages the traffic, in the end instead of comparing SD-WAN and MPLS one-to-one as a potential replacement for one another, one should rather look at them as complementary technologies.

When you are connecting large data centres together, you will need to use a big, powerful connection with reliable service levels — MPLS and it’s highly likely that your organization already has it in place.

The SD-WAN as an overlay solution, takes your existing infrastructure and helps it run more efficiently. SD-WAN is application and user aware, which allows it to route traffic over the most effective path for high performance and low latency in near real-time. Mission-critical applications and data will still be sent through MPLS, while lower-priority apps like email can be sent over the public internet. Should there be an issue with your MPLS, SD-WAN can reroute your data through alternative channels, giving you the redundancy you need without the cost of maintaining redundant connections.

From the cost perspective, it should be noted that SD-WAN will indeed help you reduce some of your MPLS costs, however not all of them. What SD-WAN can do is help you mitigate the need to scale your expensive MPLS to meet your connectivity needs by instead letting software help maximize your current investment.

Interestingly and perhaps somewhat controversially, Verizon state in their article that the question of MPLS vs. SD-WAN security isn’t a matter of either/or. They note that since MPLS is a private network, it isn’t exposed to outside hackers via the internet and together with traditional network security capabilities like secure web gateway services and next-gen firewalls, MPLS and SD-WAN work together to help keep data safe and sound. While this may be the case, it should be stressed that with MPLS there is a risk of data transfer to third parties.

THE BOTTOM LINE

There are many variables to take into account before choosing the best connectivity fit, including geographic spread between corporate headquarters and remote branches, compliance requirements, needs around flexibility, operating budget and so on, with one universal factor: security.

While MPLS offers some protection, processing by Internet service providers carries a risk of transferring data to third parties. This is compounded because MPLS is not encrypted. On the contrary, SD-WAN is more like a VPN and allows you to send information without transmitting it to third parties. This means that SD-WAN has a security advantage – arguably a defining element when it comes to making an informed decision.

Many organizations have already begun to switch SD-WAN and whilst at the moment in majority of the cases the change is gradual and serves as enhancement to MPLS solutions, it is likely that in the near future SD-WAN will be running on most networks without the MPLS.

Brodynt’s SD-WAN services can help you connect your branch offices without compromising on security virtually in any area of the world. Should you wish to get more information, you are welcome to get in touch with us by sending an e-mail to customerservice@brodynt.com and one of our Account Managers will be happy to assist you!