What is MPLS? Definition, advantages/disadvantages and alternatives (2023)

Multiprotocol Label Switching (MPLS) was originally developed in the 1990s to enable high-speed network connections to corporate networks. It started as a proprietary protocol and was standardized by the Internet Engineering Task Force (IETF) in 2001RFC 3031.

The public internet works by forwarding packets from one router to the next until the packets reach their destination. MLPS, on the other hand, sends packets along a specific network path. This means the router spends less time deciding where to forward each packet, and the packets follow the same route every time. MPLS operates between Layer 2 (the network layer) and Layer 3 (the data link layer) of the OSI network model.

MPLS is widely used in enterprise networks but is losing popularity as a one-stop solution for network connectivity. MPLS infrastructure is expensive, complex to configure, and inflexible, making it difficult to support changes in organizational structure and new points of presence. MPLS will continue to play a role in the future, along with other connectivity options such as SD-WAN and broadband internet.

How does MPLS routing work?

When traffic enters an MPLS network, the incoming MPLS router adds an MPLS header to it. This encapsulates the data so that it can be easily forwarded to any underlying protocol.

The MPLS router assigns a Forward Equivalence Class (FEC), which is expressed by adding a label (a short string of bits) to the packet. The FEC defines routing criteria that create a standard traffic path in the MPLS network. This is called Label Switched Path (LSP). The routes are unidirectional and the return traffic is sent via a separate LSP.

The MPLS header or label stack has four fields:

• first 20 bits— the label that determines where the packet will be forwarded to.
• next 3 bits- Used for Quality of Service (QoS) priority and Explicit Congestion Notification (ECN), an extension of the IP protocol that allows networks to handle congestion without dropping packets.
• Next 1 bit- This is the End of Batch field. When set, indicates that the packet has reached the end of the MPLS network path.
• last 8 bits—Time to Live (TTL).

The primary goal of MPLS is to improve network traffic performance and reliability. But it can also have security benefits. Although MPLS connections are not encrypted by default, they are often isolated from the rest of the network, creating a separate virtual tunnel similar to a virtual private network (VPN). Learn more in our MPLS vs VPN comparison below.

How is MPLS used in organizations?

Service providers and organizations use MPLS to implement network connectivity with predictable QoS. They do this by defining LSPs (standard network routes) that meet the required values ​​for traffic delay, jitter, packet loss, and idle time.

For example, an MPLS network can have three tiers of service that prioritize different types of traffic: tier 1 with the highest QoS for voice or video conferencing, tier 2 for time-sensitive traffic, and tier 3 for “time-sensitive” traffic. best effort".

MPLS also supports traffic isolation and the creation of virtual private networks (VPNs), virtual private LAN (VLAN) services, and virtual leased lines.

Related content: Read our guide toAffordable MPLS alternatives

Advantages and disadvantages of the MPLS network

One of the key benefits of MPLS is that it supports and manages multiple protocols and transmission media. It supports communication over IP, Ethernet, Asynchronous Transfer Mode (ATM) and Frame Relay. You can use any of these protocols to create LSPs.

Other advantages of MPLS are:

• Suitable for real-time applications that require very low latency.
• Suitable for mission-critical data transmissions that require high reliability.
• Ability to manage multiple voice and data applications on the same MPLS network.
• Ability to manage different types of data transfers with different priorities and service levels.
• Ability to allocate a certain percentage of bandwidth to different types of data.
• Ability to scale network by providing additional bandwidth.

The disadvantages of MPLS include:

• Very expensive compared to other connectivity methods as it is designed to ensure high bandwidth, high performance and competitive SLAs.
• It typically uses private connections that are resource-intensive to deploy and update.
• There is no central point of operation for provisioning or reconfiguration of new sites.
• Designed for peer-to-peer connectivity not supported in cloud environments.
• It requires dedicated infrastructure and can only operate where that infrastructure is provided. This means that MPLS is not relevant for many points of presence and cannot be used to support remote users or SaaS applications.

MPLS alternatives

MPLS vs Internet Connectivity

Both Internet and MPLS are the main options for enterprise connectivity. Internet is the cheapest option but has drawbacks, while MPLS offers more reliable connectivity at a premium price. Both MPLS and Internet networks support full-mesh site-to-site communications and various Layer 1 media (e.g. T1, DSL, Ethernet).

The main differences between MPLS and internet connectivity are:

• Operator-MPLS connectivity is based on a single operator, while the Internet is unrestricted and can communicate through different operators.
• prioritization– MPLS providers guarantee packet priority and delivery, but the Internet does not.
• Voice and video use cases—MLPS is the preferred option for voice and video communications as packet delivery is prioritized.
• SLA—MPLS has a defined service level agreement with high service, while Internet SLAs vary.
• Cost—MPLS is more expensive than Internet connectivity.
• security—MPLS is considered private and more secure than the public Internet.

MPLS x VPN

A virtual private network (VPN) enables remote locations to connect to an organization's network by transmitting encrypted data.

VPNs use different encryption standards such as RSA, TripleDES and EAS. VPNs mask the user's public IP address and replace it with a private IP address. They guarantee confidentiality and integrity through a cryptographic tunneling protocol and sender authentication. VPNs use different security protocols like IPsec, PPTP and LT2P.

The main differences between MPLS and VPN connectivity are:

• Speed-High-speed Internet is generally available at a significantly lower cost than MPLS, making VPN cheap for high-performance applications. However, the internet connection is also less reliable than MPLS connections.
• Security-MPLS is viewed as a private network with isolated infrastructure and isolated routing protocols. Therefore, it does not have encryption by default, so a network security breach could easily compromise all data. VPN, on the other hand, relies on the unsecured, public Internet and will therefore always include authentication and encryption, which ultimately provides more security.
• privacy—VPNs use various security measures to protect private data. It is difficult for an attacker to break into the virtual tunnel and crack the encryption. Data encryption means that even if attackers gain access to network traffic, they cannot read or use the data.
• Cost-VPNs tend to be cheaper because MPLS requires dedicated infrastructure.

Although MPLS and VPN technologies are often viewed as competitors, they can also work together. For example, a hybrid cloud company could use MPLS to reliably connect its physical locations and VPN to securely connect its cloud data centers. In this scenario, each resource is associated with the optimal technology. The downside is the inconsistency and increased complexity of the infrastructure.

MPLS x IPsec

IPsec is a set of protocols used to establish encrypted connections between devices. Helps keep data transmitted over public networks secure. Often used to set up VPNs, IPsec works by encrypting IP packets and verifying their origin.

The name IPsec stands for "Internet Protocol (IP) Security". The Internet Protocol is the main routing protocol used on the Internet. Networks use IP addresses to indicate where to send data. IPsec adds encryption and authentication to this process.

Cost

• MPLS is considered a private network that does not require encryption.
• IPsec requires an encrypted tunnel between every two edges of the network, so a 10-edge network requires 100 tunnels. This increases the cost of the equipment used to build and manage IPsec tunnels. It also requires highly skilled personnel to manage and maintain hardware and networks.

security

• MPLS is considered secure even when the data transmitted over an MPLS network is transmitted unencrypted because it is based on a private connection. However, anyone with physical access to the MPLS connection can intercept the communications.
• IPsec VPN data is always encrypted. However, since it traverses the public internet, it is at greater risk of eavesdropping and espionage.

reliability

• MPLS lines are private networks that come with a clear SLA that focuses on reliability and availability as the core value of the service.
• IPsec connections rely on the infrastructure of the Internet and are therefore less reliable and subject to the instability and unpredictability of the public Internet.

QoS

• MPLS allows users to prioritize specific traffic on the network. This is useful if your business uses VoIP or other latency-sensitive applications.
• IPsec also enables QoS, but since the underlying infrastructure is the Internet, connection drops are a common problem that QoS cannot solve.

MPLS x SD-WAN

Software-Defined Wide Area Network (SD-WAN) is a technology that uses the software-defined networking concept to distribute network traffic across a wide area network (WAN). SD-WAN automatically determines the most efficient method of forwarding application traffic between branch offices and data center locations based on configured policies.

bandwidth usage

• SD-WAN efficiently uses all available network bandwidth. Sites connected by SD-WAN can be easily updated by adding new links.
• MPLS requires expensive private connections to increase available bandwidth.

return transport

• SD-WAN can create direct and dynamic connections between branch offices, cloud data centers and the Internet, making it much more efficient than MPLS.
• MPLS connects branch offices to a central data center via a hub-and-spoke WAN model, with each remote site connected via a single MPLS connection. As a result, access to the internet and cloud services must first be routed to a centralized data center and from there to its final destination, increasing latency and consuming valuable MPLS bandwidth.

Cost

• SD-WAN lowers costs by combining the use of MPLS and the Internet to build the wide area network. Using the Internet for less sensitive applications allows lower costs per Mbit/s
• MPLS is expensive because it relies on dedicated, private infrastructure and is coupled with an SLA for reliability and high availability.

security

• MPLS networks are considered secure because they are based on a private link infrastructure.
• SD-WAN uses encrypted communication as the data is transmitted over the public internet.

Learn more in our in-depth guide toMPLS alternatives

The move from MPLS and SD-WAN to SASE

MPLS offers low latency, minimal packet loss, predictable performance, and centralized management. However, MPLS also has disadvantages, including cost, capacity limitations, and time-consuming deployment. Internet connections have always been a cheaper, lower-quality alternative to MPLS, but they don't offer the uptime and performance guarantees of a dedicated connection.

In the early days of MPLS, organizations used it for active workloads along with internet connections for passive backups. Security was based on a firewall. Over time, the WAN has become expensive and complex without agility. Administrators must provision and configure devices manually, increasing operational costs. Nowadays this configuration is very complicated to maintain.

SD-WAN should help close functional gaps in the public internet and MPLS. SD-WAN provides automated multi-link connectivity, expanding overall network capacity and accelerating the deployment process. It can automatically adapt to dynamic network conditions to optimize connection costs.

While SD-WAN is a flexible and cost-effective option, deploying a full WAN transformation alone is not enough. SD-WAN cannot provide the mobility, security, and cloud readiness needed to support digital business. It connects directly to the Internet and bypasses traditional security measures. IT teams often face technology silos due to poorly integrated and individually managed products.

Secure Access Service Edge (SASE) is an evolution of SD-WAN with a cloud-based approach to security. SASE can be used to replace MPLS and SD-WAN functions, helping to meet the organization's changing connectivity and security needs. It's also a security platform, not just a network system: it offers SD-WAN network optimization and cloud security as a managed service.

This converged approach to security and connectivity, delivered via a cloud service, eliminates the need to route traffic back through a central location. SASE platforms are geographically distributed, which helps reduce latency for remote users and applications by constantly reviewing content and centrally enforcing security policies.