In most networks, each router decides where to send a passing data packet by conducting an IP lookup and referencing its routing table. Performance on the network may suffer due to this procedure, particularly for speech and video applications that depend on low latency.
MPLS addresses this issue by leveraging predetermined “labels” on each packet that devices throughout the network can read to determine where to send them. It reduces forwarding tables on switches, lowering costs and improving network performance.
What is MPLS?MPLS is a networking technology that routes packets using predetermined “labels” rather than the destination IP address that other routing protocols rely on. These labels are appended to the packet header by network devices and indicate forwarding equivalence classes (FECs or CoS) that classify data according to its performance characteristics. Real-time applications like voice and video are prioritized, so they’ll travel faster over the highest quality paths while best-effort traffic gets rerouted to other pathways.
Determining how to route packets can take longer with other routing technologies. Each router examines the packet’s header and consults its internal routing table before deciding how to forward the information. It can be a very computationally intensive task, especially for networks with large routers.
With MPLS, each device in the network reads a label and knows that it’s part of an LSP. It then uses this information to forward the packet to the correct destination. Devices can also change the label attached to a packet, making it more difficult for someone to spoof the system.
As a result, MPLS provides a high level of security and reliability. MPLS is more resilient than broadband Internet connections, which can be vulnerable to attacks. It’s often used to connect remote branch offices that need access to central business applications and data centers.
In addition to its scalability, MPLS can offer a variety of service level agreements (SLAs). Businesses can establish different classes of priority for certain types of data transmission. It can benefit organizations that want to prioritize their mission-critical applications and ensure they have the fastest possible performance.
MPLS operates at OSI layer 2.5, above the network layer (layer 3) and below the data link layer (layer 2). That makes it ideal for connections between business locations, but it also offers the capacity to form virtual private network (VPN) services. It allows businesses to logically separate their VPN traffic into a tunnel isolated from other data across the MPLS network.
What Are the Advantages of MPLS?
The speed and accuracy of data transactions are essential to most business processes. Whether it’s a phone call that connects or drops, employees having access to 3rd party resources, or customers visiting your website and downloading content quickly, it all depends on the technology behind how those data transmissions occur.
To help ensure the best possible data delivery, many businesses turn to MPLS or multiprotocol label switching. The technology offers enterprise-grade WAN connectivity and prioritizes business data routes. It helps ensure that critical data always takes the most efficient path or paths through the network, which can be very important for mission-critical applications like VoIP and videoconferencing.
Unlike IP, which allows packets to choose their paths, an MPLS data packet is assigned a unique label that predetermines the path it needs to take. The first router in the path reads that label and then forwards the packet to the next router. As each router reads the label, it determines where to route the packet, which helps ensure that data arrives at its destination quickly and without disruption.
Moreover, because the label is attached to each packet rather than the IP address, routers must perform less work on each packet. They can process more packets simultaneously, allowing for better performance.
Another advantage of MPLS is that it can be used with various networking protocols and transmission media. This flexibility helps reduce costs by allowing organizations to utilize existing equipment when they migrate to an MPLS network.
In addition, because the underlying protocol isn’t changed, other devices throughout the network can easily read an MPLS label and know what to do with the packet. As a result, this reduces the need for those devices to perform manual IP destination lookups, which is very time-consuming.
Although there are several advantages to using an MPLS network, there are better solutions for some companies. For example, an MPLS network is expensive because it requires a private connection and can be challenging to deploy and upgrade. Additionally, supporting remote locations and SaaS applications can be challenging because it’s built for point-to-point connectivity and cannot scale to the cloud.
What Are the Disadvantages of MPLS?
MPLS is more scalable than packet or circuit switching and offers high levels of performance, which can help your organization deliver better end-user experiences. In addition, MPLS reduces network traffic congestion and can increase network availability. It is because it eliminates the need for routers to perform routing lookups based on destination IP addresses and instead uses labels to create forwarding paths for data packets. It also allows routers to determine the best route for a given packet based on specific criteria, which can be helpful when routing data through your network.
With MPLS, routers at the network edge and core can assign a label to incoming packets, which indicates what kind of service they require. This information can be added to the packet header and enables traffic to be sent down the appropriate path, which results in a faster, more efficient network. For example, real-time applications like voice and video can be assigned a higher priority and sent down the fastest, lowest latency path. Meanwhile, non-real-time traffic like CRM and email can be sent over a more cost-effective, lower-quality path.
In addition, MPLS identifies pathways network “roads” that are most suitable for particular types of traffic. This process can be analogous to how a GPS can identify which roads are most likely to take you to your destination rather than trying to figure out the exact address of every town and city along the way. It can be advantageous in organizations with multiple business locations, as it can help to avoid duplication of network infrastructure and resources.
However, one disadvantage of MPLS is that it doesn’t encrypt packets, so anyone who intercepts a packet can read the underlying information. It can concern many organizations, especially those with strict security and privacy requirements. In addition, with an MPLS cloud service, you must trust your network provider to ensure that their hardware is configured properly and to route traffic correctly.
In contrast, SD-WAN encrypts packets and provides complete visibility into the underlying network architecture. That makes it a more secure and trustworthy option for organizations with critical data and applications. As such, SD-WAN has become a popular alternative to MPLS, although organizations that need scalability and security may still find that MPLS is the better choice.
What Are the Costs of MPLS?
A typical MPLS network carries voice, video, and data over multiple connectivity points. These connectivity points can mix WAN connections and private IP circuits. It is a highly scalable and protocol-independent solution that assigns labels to each packet, controlling its path over a private vast area network. It dramatically improves traffic speed, so users can experience minimal downtime while connected to the network.
When an incoming packet is received at the ingress router (called the Label Edge Router), it gets assigned to a Forwarding Equivalence Class (FEC) based on its destination. Then, the router applies a label to the packet and encapsulates it into an LSP. At the next network hop, the routers in the MPLS network will use these labels to direct the packet toward its final destination. In addition, they will not need to do the extra lookups required by IP routing. In other words, MPLS eliminates the cumulative delay caused by routers determining the best route for a packet.
As an additional feature, MPLS can support Traffic Engineering, which allows administrators to prioritize certain types of traffic over others. It helps to reduce congestion in the network by sending the most critical data over more reliable routes. Rerouting traffic to other paths also frees up capacity on routes experiencing high latency.
Finally, MPLS enables businesses to hide the complexity of their networks by creating virtual connections that resemble long ethernet cables. These connections are then called Virtual Private LAN Services (VPLS). That makes it easy for employees at different sites to connect and collaborate over the Internet.
MPLS can be expensive, particularly for businesses with high bandwidth requirements or expanding their networks geographically. In many cases, these network expansions require the purchase of additional infrastructure from the carrier that manages their existing MPLS network. It can become costly, primarily if a business uses MPLS to backhaul data between multiple locations and the cloud provider. Moreover, MPLS can be slow to provision new connections, requiring the network to have dedicated infrastructure at each location. It can take between 60 and 120 days.