MPLS and SD-WAN: Unravelling the network conundrum

Introduction

The digital age has made it necessary for organisations to rely heavily on the network infrastructure to run day-to-day operations. As such, choosing the right networking solution is critical for business success. With the rise of cloud computing and the increasing demand for more advanced solutions, there has been competition between traditional networking technology like MPLS and the next-generation SD-WAN.

Organisations everywhere are confused about choosing between these two networking solutions.

If you also face the same issue, this article aims to answer that question through a comprehensive comparison between SD-WAN and MPLS.

We will explore the pros and cons of each technology, highlight their differences, and offer insights on which solution might best suit your organiation's unique requirements.

What is MPLS?

MPLS, or Multiprotocol Label Switching, is a protocol-agnostic technique for efficiently routing network traffic within Wide Area Networks (WANs). MPLS networks utilise labels to direct packets across the network, resulting in faster and more efficient data transfer. MPLS has been a go-to solution for businesses seeking reliable and secure connectivity for several decades.

Use cases of MPLS for businesses

MPLS has long been favored by enterprises due to its reliability, predictable performance, and strong security features. It is ideal for businesses with the following use cases:

• Connecting multiple locations: MPLS networks excel at connecting geographically dispersed locations, such as branch offices or data centers. It ensures consistent connectivity, allowing organisations to establish seamless communication and access critical resources.
• Real-time applications: MPLS offers low latency and minimal packet loss, making it suitable for applications requiring real-time data transmission, such as video conferencing, voice over IP (VoIP), and virtual desktop infrastructure (VDI).
• Security and compliance: MPLS networks provide inherent security features, including private connections and traffic segregation. This makes them an excellent choice for industries that handle sensitive data, such as healthcare, finance, and government sectors.

What is SD-WAN?

SD-WAN, or Software-Defined Wide Area Networking, is a modern networking approach that abstracts the underlying network infrastructure and enables centralised management and control of the WAN. By utilising software-defined principles, SD-WAN provides organisations with increased flexibility, agility, and cost savings, making it a compelling alternative to traditional MPLS networks.

Use cases of SD-WAN for businesses

SD-WAN presents several compelling use cases that address the evolving needs of modern businesses:

• Cloud connectivity: With the increasing adoption of cloud services, SD-WAN offers optimised connectivity to cloud platforms. It can dynamically route traffic to the most suitable path, improving performance and minimising latency. 
• Cost optimisation: SD-WAN leverages multiple transport options, including MPLS, broadband, and LTE, enabling organisations to reduce reliance on expensive dedicated circuits. It provides intelligent traffic routing, allowing businesses to utilise cost-effective connections without compromising performance.
• Scalability and agility: SD-WAN's software-defined nature allows for rapid deployment and scalability. It simplifies the addition of new branch locations, reduces configuration complexity, and enables centralised management, saving time and resources.

How does SD-WAN work?

SD-WAN simplifies network management by using software to control traffic and improve performance. Here’s a breakdown of how SD-WAN works:

• Centralised control: SD-WAN is built on a centralised control plane, a software layer that manages the network. Unlike traditional WANs, where administrators must manually configure individual routers at each branch, SD-WAN allows you to control the entire network from one central location.
  This centralised control allows you to easily create and apply policies that dictate how traffic should be routed across the network. This means reduced manual work and fewer chances for errors, as changes can be deployed across all branches at once.
• Intelligent traffic management: SD-WAN is designed to optimise network performance by dynamically managing traffic in real-time. It can prioritise different types of data based on the business’s needs. For example, SD-WAN can prioritise critical applications like video conferencing or cloud services, while less urgent traffic, like file downloads, can be deprioritised. This ensures that important tasks receive the necessary bandwidth for smooth operation, even during periods of high network usage.
• Use of multiple connections: One of SD-WAN’s key features is its ability to use multiple types of network connections simultaneously. SD-WAN can connect branch offices via MPLS, broadband internet, LTE, or other WAN links.
  SD-WAN improves network redundancy by combining different connection types. If one link fails or becomes congested, traffic can be rerouted through another link without interrupting service.
  This also boosts bandwidth (network capacity), as the SD-WAN system can use multiple connections to handle higher data loads. This hybrid approach ensures better performance and reliability.
• Enhanced security: Security is a crucial concern for any business network, and SD-WAN addresses this by incorporating advanced security features. Virtual Private Networks (VPNs) are often used across WAN connections to ensure data is encrypted and protected.
  SD-WAN solutions also offer more robust security policies and controls, allowing you to secure traffic at each point in the network. Since the security configurations can be centrally managed, monitoring and enforcing security policies across all branch locations becomes easier.
• Simplified network management: With traditional WANs, each router or gateway must be managed and configured separately. SD-WAN simplifies this by applying operational rules from the central controller to all connected devices.
  This reduces the need for manual management of each gateway or router. It also streamlines network maintenance, making it easier to roll out updates, apply security patches, or adjust policies.

How does MPLS work?

Unlike traditional routing methods that rely on IP addresses, MPLS uses labels to direct data packets through a network. This labelling system allows faster packet forwarding, reducing delays and improving overall network performance. Here’s how it works:

• Label assignment: In an MPLS network, each data packet is assigned a label. This label tells the network where the packet should go without needing to perform a complex IP address lookup at every stop along the way. These labels are short sequences of bits attached to the front of the packet in an MPLS header. The packet then travels along a predefined Label-Switched Path (LSP) path.
• Forwarding packets: As the packet moves through the network, routers along the path use the label to forward it. These routers, called Label Switch Routers (LSRs), don’t need to examine the packet’s IP header (which contains its source and destination). Instead, they focus on the label, which simplifies the decision-making process and results in faster packet forwarding.
  Each router in the MPLS network swaps the incoming label for a new label that tells the next router where to send the packet. This process continues till the time the packet reaches its final destination. MPLS routers store these labels in a Label Information Base (LIB), a table that tracks the best routes for forwarding traffic.
• Predefined routes: The Label-Switched Path (LSP) is predetermined, meaning packets with the same destination always follow the same route through the network. This ensures consistency in delivery, as opposed to traditional Internet routing, where packets may take different paths based on network conditions.
  Each packet belongs to a Forwarding Equivalence Class (FEC), which groups packets that should follow the same LSP. Routers use these FECs to determine how packets should be handled, improving data transfer efficiency.
• Multiple protocol support: MPLS can work with various network protocols, such as IP (Internet Protocol), ATM (Asynchronous Transport Mode), and Ethernet. This flexibility is why it’s called Multiprotocol. As long as the MPLS labels can be read the MPLS labels, it can forward any packet, regardless of the underlying protocol.
• Quality of Service (QoS): MPLS also supports Quality of Service (QoS), meaning you can prioritise certain types of traffic. For example, real-time applications like voice or video calls can be given higher priority to ensure smooth performance. This level of control over traffic types helps maintain network reliability, even during periods of high traffic.

SD-WAN vs. MPLS: The core differences

SD-WAN (Software defined wide area network) and MPLS (Multiprotocol Label Switching) are two technologies that enable businesses to connect their sites to a Wide Area Network (WAN).

While both technologies offer connectivity between remote sites, they differ in how they handle traffic, security, and cost.

Here are some of the core differences between SD-WAN and MPLS that you might want to consider:

• Traffic handling: MPLS uses a dedicated physical network to route traffic, which means that the path is predetermined and may not be the most efficient route. In contrast, SD-WAN utilises software to determine the optimal path for traffic based on network conditions. This results in the faster and more efficient transfer of data.
• Security: MPLS is a private network and is inherently secure. However, SD-WAN can provide additional security features such as encryption, firewalls, and intrusion detection, which can help protect against cyber threats.
• Cost: MPLS is typically more expensive than SD-WAN due to the need for dedicated physical network infrastructure. On the other hand, SD-WAN uses existing Internet connections and can be managed through software, resulting in lower costs.
• Flexibility: MPLS is a rigid network technology that is difficult to change or scale, while SD-WAN is flexible and can be easily modified or expanded to accommodate changing business needs.
• Quality of Service (QoS): MPLS provides a consistent and reliable Quality of Service (QoS) for voice and video applications, while SD-WAN can prioritise certain types of traffic to improve QoS.

Let's now take a look at the advantages of SD-WAN over MPLS.

Advantages of SD-WAN over MPLS

Below are five advantages of SD-WAN over MPLS that organisations can leverage:

• Cost savings: SD-WAN comes with the benefit of cost savings as it reduces the need for expensive hardware and replaces it with low-cost internet connectivity.
• Increased agility: With SD-WAN, you can adapt and scale your networks more quickly. It helps them to respond to changing business needs more easily.
• Enhanced network visibility: SD-WAN offers more detailed network visibility and control, allowing network administrators to quickly identify and resolve network issues.
• Better application performance: SD-WAN optimises traffic flows and dynamically chooses the best traffic path, improving application performance.
• Redundancy: In SD-WAN, you get redundant connections. It means failure of one connection will lead the traffic to reroute to a backup connection.

Drawbacks of SD-WAN compared to MPLS

While SD-WAN offers flexibility and cost savings, it also has certain drawbacks compared to MPLS. These include:

• Routing control: With MPLS, routes are manually defined, ensuring that data packets follow the same path. This stability means you have consistent performance and predictability.
  In contrast, SD-WAN relies on the public Internet, where packets may take different routes each time they are sent. This variability can lead to lost packets and inconsistent network performance.
• Reliability: In MPLS, traffic is prioritised over the service provider’s backbone network, making it less susceptible to delays and disruptions. Additionally, MPLS services often include Quality of Service (QoS) guarantees, ensuring critical applications receive the necessary bandwidth.
  SD-WAN, on the other hand, uses best-effort Internet services. This means that while SD-WAN can adjust traffic routes dynamically to avoid issues, it may still experience occasional packet loss, which can impact application performance.
• Real-time application performance: MPLS often provides a better experience for real-time applications. This includes voice calls and video conferencing. It supports multiple classes of service that maintain the quality of real-time data as it travels across the network. This feature is especially crucial for organisations that rely on uninterrupted communications.
  In contrast, while SD-WAN can optimise traffic for these applications, the inherent variability of Internet connections can still lead to performance issues.

Comparing the cost: SD-WAN vs. MPLS

Regarding the up-front costs of both options, SD-WAN tends to be cheaper. The setup cost of SD-WAN is typically lower than those of MPLS connections. 

Additionally, an SD-WAN setup often eliminates the need for special hardware like routers or additional infrastructure, reducing upfront costs.

In terms of recurring costs, an SD-WAN solution typically costs less over the long term than MPLS, especially when using public internet circuits as the underlying technology.

However, the pricing for each is determined by the data plan and can be based on usage or be more consistent regardless of usage. 

Down the line, it's clear that SD-WAN offers a cost-effective alternative to MPLS. Its low upfront costs, pay-as-you-go structure, and redundancy capabilities make it a more cost-efficient choice.

Network performance: SD-WAN vs. MPLS

SD-WAN is known for its ease of use, fast deployment and reduced complexity and cost compared to MPLS. The solution is easy to set up, making it an ideal option for business applications like video and audio streaming, cloud applications and SaaS solutions. 

However, SD-WAN solutions typically offer less secure connection options and limited support for more sensitive and private data transfers.

On the other hand, MPLS networks are a more secure and private solution as data travels via private dedicated lines between sites and is well-suited for more complex, larger enterprise networks. While more expensive, it also offers a guaranteed service-level agreement.

Why is SD-WAN better than MPLS?

SD-WAN comes with a handful of advantages over MPLS. It includes superior scalability, cost savings, and reliability compared to traditional Multiprotocol Label Switching (MPLS).

The increased flexibility and optimisation of SD-WAN lets businesses benefit from multiple public networks to access private resources. This way, companies can ensure that customer demands are met more efficiently.

As an overlay technology, SD-WAN requires minimal investments in expensive infrastructure, enabling companies to save on network costs. It is also much easier to scale with increasing demand and offer dynamic network changes to maintain customer satisfaction.

In a nutshell, SD-WAN is a secure, reliable and scalable solution over MPLS.

The Right time to switch from MPLS to SD-WAN

MPLS has been the traditional backbone of enterprise WAN networks for more than two years. On the other hand, SD-WAN offers businesses increased visibility, application-specific routing and, more recently, security.

There are a few factors to consider for companies considering the transition from MPLS to SD-WAN.

Do you want your network to be easily scalable to keep up with future growth? How important is network performance? What services do you need to be deployed on the network? These questions can help you identify the best time to switch from MPLS to SD-WAN.

Simply put, it is up to you to assess your specific needs when deciding whether or when to transition from MPLS to SD-WAN. You must remember your requirements while partnering with a knowledgeable service provider.

How to choose the right networking solution for your organisation

Selecting the appropriate networking solution for your organisation requires careful consideration of various factors. Here are some key points to evaluate when choosing between MPLS and SD-WAN:

• Business requirements: Assess your organisation's specific needs, such as connectivity, performance, security, scalability, and cost. Consider factors like the number of locations, applications used, and data sensitivity.
• Network traffic: Analyse your network traffic patterns and requirements. Determine if your business relies heavily on real-time applications, cloud services, or if you have high bandwidth
• Budget considerations: Evaluate your budget and cost constraints. MPLS networks typically involve higher upfront costs due to dedicated circuits, while SD-WAN offers cost savings by utilising diverse transport options. Consider long-term ROI when making a decision.
• Future growth and scalability: Consider the scalability of your organisation. If you anticipate rapid growth, SD-WAN's agility and ease of deployment make it a viable option. MPLS may be more suitable for businesses with stable and predictable growth patterns.
• Security and compliance: Assess the security requirements and regulatory compliance standards of your industry. MPLS networks inherently provide strong security features, making them advantageous for organisations dealing with sensitive data. However, SD-WAN can incorporate robust security measures through encryption and advanced threat detection.
• Vendor evaluation: Thoroughly evaluate potential service providers or vendors. Consider their reputation, track record, expertise, and support capabilities. Ensure they align with your organisation's goals and can deliver the required service levels.
• Hybrid approach: In some cases, a hybrid approach may be the best solution. By combining MPLS and SD-WAN, businesses can leverage the strengths of both technologies. MPLS can be used for critical applications requiring high reliability and security, while SD-WAN can be implemented for cost-effective connectivity to less sensitive locations.

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