Are you looking to migrate to cloud? Are you experiencing bandwidth constraint with your existing wide area network (WAN) infrastructure? Is your organisation’s IT landscape evolving rapidly? If so, have you considered transforming to a software-defined WAN (SD-WAN) solution? In this blog, we highlight why the industry is seeing an increased interest in SD-WAN over MPLS and why your organisation should consider shifting today.

What is the difference between MPLS and SD-WAN?

Before we get ahead of ourselves, let’s have a look at MPLS, a traditional WAN technique, and SD-WAN, a new way organisations are managing their network at the edge.

Multiprotocol Label Switching (MPLS) has been a popular WAN technology used traditionally in telecommunications environments. Organisations are provided with private connections between their data centres and offices. The technique carries data across the network via fixed competent routes. It is ideal for time-sensitive traffic from voice to video to email-based applications.

SD-WAN reduces the dependency on MPLS by leveraging local break out points to the internet and utilising cloud technology to manage WAN infrastructure. Network traffic is logically and efficiently routed over ISPs of the customers’ choice from each endpoint. It provides secure connections between an organisation’s data centre and offices over various network technologies, such as NBN and 4G, instead of requiring a purpose-built network.

What are the pros and cons of both?

SD-WAN – The Advantages

Many businesses have replaced their MPLS network with SD-WAN. The areas of difference relate to cost, security, and performance. Some of the following advantages are very clear, others less apparent depending on the situation:

More Cost-Effective. SD-WAN offers optimal user experience while eliminating the need for expensive VPNs. SD-WAN provides higher-speed options for multi-point connectivity. By using distributed, private data traffic exchange and control points, such as broadband, DSL and 4G LTE, at lower cost users have more secure, local access to the services that they need – whether from the network or the cloud.

Improve SaaS application performance. SD-WAN can recognise applications and adapt bandwidth and other services accordingly. It can initiate multiple parallel connections and balance the data flow between them. SD-WAN can also create new connections should there be a need to increase the bandwidth and ensure time-sensitive applications are not compromised, For example, SaaS application traffic can be routed directly via local internet breakout to reduce bandwidth drainage issues and hefty costs relating to contention and backhauling to a data centre for processing and redistribution.

Simplified QoS. SD-WAN provides real-time traffic monitoring. Organisations can prioritise essential applications, such a video conferencing and focused emails, across the WAN and divert business-critical traffic during periods of network disruption at every location. SD-WAN can also be upgraded by adding new links – generally without changes to the WAN infrastructure or network.

Central Management. SD-WAN orchestration allows the organisation’s network to be managed and monitored via a centralised dashboard. It reduces management overhead and simplifies network operations while providing complete visibility and control over traffic routing.

Unified security. It is deceptive to think that MPLS provides a secured and managed link between branch offices and data centre through the ISP’s internal backbone. Traffic still needs to be inspected for malware and other exploits, which requires deploying a firewall and additional security functions. SD-WAN can unify secure connectivity by integrating security, policy and orchestration via a single management platform. Organisations can benefit from end-to-end encryption across the entire network. By embedding a wide array of security tools – including firewall, anti-virus and anti-malware, SD-WAN enables data to be secure during transit and provides in-depth inspection of the traffic.

More protection. MPLS is an option available to any SD-WAN solution. When there are cases where MPLS is much less expensive, or when concerns about security or reliability are more important than cost differences, SD-WAN can run over an MPLS connection to provide more protection and functionality than an MPLS solution alone. SD-WAN provides a more significant amount of flexibility, more granular traffic control, integrated security, and the ability to leverage multiple connection strategies – such as MPLS and public internet -using the same SD-WAN deployment.

SD-WAN – The Drawbacks

Not suitable for all organisations. It’s not great for organisations where all business applications are located on premise as there is limited benefit to channel all traffic from the edge out to the internet and then back down from the internet to the Head Office.

Possible Local Site Outage. Occasionally, when using SD-WAN, there is a chance of data packet loss and internet uplinks failing. However, this can be offset by organisations choosing an ISP which can offer consistent reliability in their internet connections and ensure that there are multiple services connected e.g. NBN and 4G to ensure reliability.

MPLS – The Advantages

Although we have listed the many advantages of deploying SD-WAN, MPLS could be considered a better choice, for reasons stated below:

High QoS. MPLS excels at keeping a business’s most crucial traffic flowing. It is ideal for businesses which use virtual applications such as VoIP, video conferencing or virtual desktops. This technique works without compromising the quality or signal.

It is reliable. MPLS uses packet-forwarding technology and labels to make data forwarding decisions. The traffic is specially labelled to assist with identifying what data is critical and enabling data forwarding rules to be established, which is particularly important when there are many users on the shared network.

MPLS – The Drawbacks

The advantages of MPLS include scalability, improved performance, reduced congestion. However; it also comes with several drawbacks, including:

Its bandwidth is expensive. An MPLS service must be purchased from and configured by a telco provider which is far more expensive than running data over the internet. We are in a world where organisations are churning through content that requires a high level of bandwidth, from videos to virtual reality. It can also become very costly when organisations need to increase the bandwidth for their MPLS network when compared to other technologies such as public internet connections.

It is inflexible. It can take up to a few months to provision new services. MPLS connections tend to be rigid, fixed connections that can’t easily adapt to the sort of interconnectivity between branch offices that today’s dynamic networks require. They also don’t provide support for things like application recognition or sophisticated bandwidth management for latency-sensitive applications.

It is complex to deploy and manage. Although an ISP manages MPLS, organisations still need skillsets and resources to maintain the integration of their internal network with MPLS and ensure consistent policies apply across the MPLS network as new sites come online and new services are requested.

Visibility is limited. MPLS offers limited visibility about the network. A separate solution is often required to achieve that level of visibility required.

Poor performance. From a performance perspective, MPLS provides a reliable, fixed level of bandwidth. With a continuously expanding volume of data being generated by modern networks and devices, many organisations are leasing MPLS connections to manage increased workloads. However, the organisations are encountering the risk of constrained connectivity, particularly as the connection cannot understand the nature of the traffic and adjust accordingly. Also, while all traffic needs bandwidth to function, some applications – such as voice and video – have latency requirements that require continuous monitoring. When several applications are running through the same connection tunnel, latency-sensitive traffic needs to be prioritised, which requires application recognition, traffic shaping, load-balancing and prioritisation of different connections. MPLS is not capable of doing this.

Cost effective
Improved SaaS performance
Simplified QoS
Centralised SaaS service for administration
Carrier agnostic
Unified security
Not dependent wholly on MPLS
More protection
Guaranteed performance for real-time traffic
Reliable connection when deploy with redundant paths.
Relies on the public internet
Requires the right skillset
Predetermined routes need to be configured by Telco.
Bandwidth can become expensive
Complex to manage
Visibility is limited
Performance degradation with increased traffic
Difficult to source single global provider
Doesn’t support direct access to the cloud from the edge.

What’s best for my business?

What’s best for my business- is a difficult question to answer. Selecting the right solution depends on what environment you’re working in, where your business applications are hosted, where your users are connecting from and what the specific needs of your business are. Each technology has a different role to play; finding the balance is key. MPLS functions in a predictable way, thus guaranteeing time-sensitive traffic is delivered on time at the trade off to lack of flexibility and increased costs. From cost and agility to the ease of use and scalability, an organisation cannot underestimate the benefits of SD-WAN. If organisations are using more advanced cloud-based applications and workflows become more complex, the more flexible and dynamic connectivity they require. SD-WAN is the clear winner.

When should organisations shift from MPLS to SD-WAN?

Organisations should consider deploying SD-WAN when;

  • They want to upgrade their bandwidth.
  • They are looking after a more flexible arrangement as they come out of contract with their ISP
  • They are looking at using more cloud-based services
  • They want to improve their security, agility and visibility within their network
  • They are looking at improving application performance
  • They are identifying their reducing network costs