What is Multiprotocol Label Switching (MPLS)?

MPLS-multiprotocol-label-switching

MPLS stands for Multiprotocol Label Switching, a networking technique used to direct data packets efficiently along predefined paths to their destinations. It was designed to provide faster, more reliable data transmission across large enterprise networks with multiple locations, using labels instead of IP addresses. 

A Brief History of MPLS

MPLS was developed in the 1990s as a technology to improve the efficiency and performance of packet-switching networks to enable fast and reliable IP packet forwarding. 

It quickly gained popularity and widespread adoption in service provider networks since it supported various protocols and provided traffic engineering capabilities. Over the years, MPLS has evolved, incorporating new features and enhancements, and is still used in both enterprise and service provider environments.

How Does MPLS Work? 

Typically, data is divided into pieces, called packets, before being sent from one location to another. Each packet contains code that routers use to decide which direction it should go on its way to its destination. 

When you order a package from Amazon, it moves from the warehouse to your home without being opened and inspected. The shipping label is scanned at each stop along the route, and the package is forwarded accordingly. 

Similarly, an MPLS network simplifies the routing process, using labels to direct and forward data packets through a network without the need to open and examine the IP header. Here’s how it works:

  1. When a packet enters an MPLS network, the ingress router at the network edge adds a short bit sequence (the label that contains forwarding information for the packet. 
  2. Specialized label switch routers, located in the middle of the MPLS network, exchange information about the labels they use through a control protocol, such as the Label Distribution Protocol (LDP). 
  3. Routers then use the labels, rather than the packet headers, to determine the appropriate next hop. 
  4. When a packet reaches the final egress router, the MPLS label is removed, and the packet is forwarded based on its original destination IP address.

MPLS networks can classify and separate traffic based on the type of data it is carrying, ensuring faster transmission for applications that require high quality, such as voice and video. 

Main Uses for MPLS 

Multiprotocol Label Switching is used in various networking scenarios and is especially useful for enterprises supporting branch offices or global locations on the network. The most common scenarios for MPLS include:

Virtual Private Networks (VPNs): By encapsulating and forwarding packets using MPLS labels, VPNs can be established over shared infrastructure while maintaining privacy and traffic segregation. 

Traffic Engineering: MPLS provides traffic engineering capabilities so network administrators can control traffic flow to direct data along specific paths, balance the load across network links, and allocate bandwidth according to application requirements. 

Quality of Service (QoS): MPLS supports QoS mechanisms to prioritize traffic based on priority-level or specific requirements so service providers can ensure that critical applications, such as voice or video, receive the necessary bandwidth, low latency, and low packet loss.

Service Provider Networks: MPLS networks can handle multiple types of traffic simultaneously, allowing service providers to offer a range of services like data, voice, video, and cloud applications. 

Pros and Cons of MPLS

In terms of cybersecurity, MPLS offers security advantages that include:

  • High performance and reliability for real-time traffic
  • The ability to handle multiple types of traffic simultaneously
  • Traffic isolation to protect sensitive data, preventing unauthorized access and eavesdropping
  • Virtual Private Networks (VPNs) to gain security, privacy, and data integrity when data is transmitted between geographically distributed sites
  • Administrative control to route traffic through specific paths or devices
  • Centralized monitoring and enforcement of security policies
  • Quality of Service (Q0S) mechanisms that lead to improved performance and user satisfaction

With the rise of cloud computing, MPLS is no longer a comprehensive solution, and it does come with drawbacks, including:

  • Higher expenses than standard internet connections, which may be cost-prohibitive for smaller businesses
  • A complexity that requires specialized equipment and expert service providers for deployment, management, maintenance, and troubleshooting
  • Limited traffic visibility, which makes network troubleshooting and monitoring more challenging

Is MPLS Still a Viable Option? 

It’s true that newer technologies like Software-Defined Wide Area Networking (SD-WAN) and Secure Access Service Edge (SASE) offer greater flexibility and cost-effectiveness, especially as enterprises adopt greater cloud presence, use more Software-as-a-Service (SaaS) applications, and hire an increasingly remote workforce.

However, since MPLS was widely adopted and implemented in many enterprise and service provider networks, migrating away from it can be a significant undertaking. Enterprises already using MPLS can use a hybrid approach to leverage the strengths of both old and new technology.

MPLS may also remain useful for large organizations with regional offices and data centers, distributed retail establishments using point-of-sale systems, and businesses that rely on real-time applications like conference-calling software.

At the end of the day, the suitability of MPLS versus alternative technologies depends on the specific requirements, budget, and priorities of each organization.

How MPLS Helps with Cloud Adoption 

Although MPLS is no longer the perfect network solution on its own, it can be combined with cloud computing technology, providing secure and reliable connectivity in certain situations where sensitive data needs to move over public internet connections and reliable performance is necessary.

MPLS helps optimize traffic flows between corporate networks and the cloud by directing traffic, allocating bandwidth, and implementing QoS policies to ensure that critical cloud applications or services receive the necessary resources and performance levels.

A hybrid approach can connect on-premises data centers, branch offices, and cloud environments, offering consistent connectivity, centralized management, and the ability to extend the organization’s network into the cloud.

MPLS networks can handle increased traffic demands, accommodate additional sites or branches, and support the growing number of cloud connections as organizations scale their cloud adoption, though it is important to note that scaling with MPLS requires more time and expertise than other methods.

MPLS vs SD-WAN vs SASE

SD-WAN, MPLS, and SASE are different networking technologies that address various aspects of network connectivity and security. 

MPLS is designed to efficiently route data traffic within a private network, using switching, traffic engineering, QoS, and VPNs with reliable and predictable performance, traffic prioritization, and secure data transmission. 

SD-WAN can replace or complement traditional MPLS, optimizing and managing wide area network (WAN) connections with features like centralized management, software-defined control, dynamic path selection, and application-based traffic routing. SD-WAN provides benefits like enhanced performance, cost savings, improved application experience, and increased agility.

SASE takes a comprehensive approach by converging network connectivity and security services. It integrates SD-WAN capabilities with security functions like Secure Web Gateways (SWG), Firewall-as-a-Service (FWaaS), Cloud Access Security Broker (CASB), and Zero Trust Network Access (ZTNA) to simplify network architecture, improve security, reduce complexity, and enhance user experience. It is particularly suitable for modern, distributed enterprises, offering secure and direct access to applications and cloud services from anywhere.

Learn how Perimeter81’s enterprise SASE solution can simplify your network architecture and provide end-to-end security and scalability, even across large distances. Book a demo today.

FAQs

Is MPLS a LAN or WAN?
MPLS is primarily associated with Wide Area Networks (WANs). While MPLS can be used within LAN environments in certain cases, its main purpose and benefits are most pronounced when utilized within wide-area networks.
What is the Difference between MPLS and the Internet?
Here are some key differences between MPLS and the Internet:

– MPLS operates within a private network infrastructure, while the Internet is a public global network that connects millions of devices worldwide.
– MPLS offers greater control over traffic routing and prioritization than the Internet enforcing QoS policies and ensuring performance for critical applications. The internet, being a best-effort network, is subject to varying levels of congestion, latency, and packet loss, which can affect performance and consistency.
– MPLS-based VPNs inherently provide a higher level of security and privacy while traffic on the Internet can potentially be intercepted or compromised.
– MPLS networks and service providers are more constant than Internet connectivity.
– The Internet offers extensive global reach, allowing connectivity to virtually any location, but MPLS relies on the availability of MPLS infrastructure, which may not be universally accessible or as widespread in certain regions. 
– The internet provides various connectivity options, including wired, wireless, and satellite, while MPLS typically relies on physical circuits or dedicated connections.
Is MPLS a Switch or Routing Technique?
MPLS labels are swapped or switched at each router. In this sense, MPLS behaves like a switch, directing packets more quickly and efficiently than traditional routing based on IP addresses.

However, MPLS also incorporates routing functionality as it relies on IP routing protocols to establish the paths and labels used for packet forwarding.
Does MPLS Operate on Layer 2 or Layer 3?
MPLS doesn’t fit perfectly into Layer 2 (Data Link) or Layer 3 (Network) of the OSI model. Since it sits between these layers, some say MPLS is Layer 2.5. MPLS networks enable fast and efficient packet forwarding and can be used with protocols at both layers.