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A Guide to Multi-Protocol Label Switching MPLS

Multi Protocol Label Switching is a fairly popular topic in computer networking. MPLS has been around for a while now, serving organizations that were at the enterprise stage.

Over the years, the advancement of technology has also given way to better solutions, but MPLS continues to be an important routing methodology that is still used today.

What is MPLS (Multi-Protocol Label Switching)?

In simpler words one may seek to define MPLS (Multiprotocol Label Switching) as a data forwarding technology that takes charge of controlling the network flow all the while increasing the speed of network flow as well.

It is by utilizing MPLS that data is given a direction or a pathway via labels instead of opting for complex lookups in the routing table at each stop. Through MPLS a number of new, enhanced and efficient control features are granted to network service providers.

This technology initially entered the market in the 90s but now it has been widely acknowledged and adopted by telecom networks.

The working of MPLS is such that normally before the advent of the MPLS when a traditional IP network welcomed the data it would pass from long network addresses and network nodes and next stop of each data packet on the network was up to each router's own decision based on the routing tables.

But MPLS has made everything far less intricate since its core job is to assign a label to each path and forward it over a predetermined path.

What are the Advantages of MPLS?

The technology of MPLS is bundled with a bunch of advantages, and some of them are listed below:

  • Reliable and tested technology: The technology for MPLS is quite reliable as it has been very well developed in the past and it successfully managed to direct routes from one point to another without a hassle.
  • Traffic management and predictability: In addition to reliability it also promises predictability of traffic within the network.
  • Zero packet loss: The quality of service that is received through this technology is actually commendable and user experience is always consistent with zero packet loss, low jitter and utterly fixed latency.
  • Suitable for organizations that are technically lacking: For organizations with lower level functionality, MPLS is the best and safest option.

What are the Disadvantages of MPLS?

Just like any technology if it has some pros then it ought to have some cons as well. Some of them are listed below:

  • Expensive solution: It is high-cost and expensive because of unavailability of competition in the market.
  • No direct access to the cloud: The technology is tailored to provide point-to-point connectivity only but doesn’t contain the feature to maintain point-to-cloud connectivity, and offers no way to directly access the cloud.
  • WAN optimization is a prerequisite: It is already quite pricey and in order to streamline the delivery, WAN optimization is required and that adds extra cost to the entire package.
  • Complex installation process: A longer time is required for MPLS to be installed and is usually handled by service providing organizations.

How does Multi-Protocol Label Switching Work?

Label Switched Paths (LSPs) are predetermined before transmision over the network. They are unidirectional paths that are between pairs of routers across MPLS networks.

When a data packet enters the network via a Label Edge Router (alternatively known as an “ingress node”), it is alloted a Forwarding Equivalence Class (FEC). The FEC for the data packet depends on the kind of data and its intended destination.

Depending on the FEC, the Label Edge Router will give a label to the packet and compress it inside a label switched path.

As the data packet passes through the network’s label switch routers, those routers direct the data by the instructions stored in the packet label. These stops between the source and destination are based on the packet label and not additional IP lookups.

At the final router of the LSP, the packet label is removed and the packet is delivered through normal IP routing.

1. Traffic class field

The Traffic Class field shows the class or priority of the IPv6 packet which is the same or close enough to the Service Field in the IPv4 packet. The Traffic Class field helps routers handle the traffic depending on priority of the data packet. If any sort of congestion occurs on the router then the data packets with the least priority are supposed to be discarded.

2. Time-to-live (TTL) field

Time to live field, alternatively known as the hop limit, is a mechanism designed to limit the lifespan or lifetime of information within a computer system or network. TTL can be implemented as a counter or timestamp attached to or even embedded in the data. As the prescribed event count or timespan is elapsed, data is revalidated or discarded.

3. Label value

Label value is the easiest to understand. It contains the value that is present with the label for the data packet.

4. Bottom of stack flag

The Bottom of the stack flag is used to show that there are no labels after it and that it is the final label for the data packet.

Why is MPLS used?

MPLS is used for the benefits that it provides and the purpose that it serves for organizations and businesses.

MPLS helps to improve uptime by transmitting data over a different path in the fast time of under 50 milliseconds (depending if the alternate path exists). MPLS also lessens the need for manual intervention your network service provider has to do to make a WAN . MPLS also reduces the chances of human error bringing down the network and causing downtime.

MPLS also can play a role in making scalable IP VPNs. MPLS makes it easy to add additional websites to the VPN. MPLS eliminates the need to configure a complex mesh of tunnels for the VPN.

Improved user experience is possible because of MPLS. By prioritising time-sensitive traffic like VoIP or instant online messages, MPLS offers several Classes of Service, allowing you to apply different settings to different kinds of network traffic.

MPLS also plays a huge role in improving bandwidth utilisation. By allowing several kinds of traffic on the same link, high priority traffic can loan capacity from lower priority traffic streams when needed. On the other hand, when the lower priority traffic needs to exceed beyond its allocated bandwidth, it can use any bandwidth capacity that's not in use by higher priority services.

MPLS is also beneficial for people who are tasked with managing the network. At times, the network can become complex. An MPLS connection between two websites can be configured to work like a prolonged ethernet cable, where the hops involved are masked or hidden from view.

If this was not enough, MPLS also helps to reduce network congestion. As we know that in a lot of cases, the shortest path that is between a source and destination isn't the most ideal one to take, as network congestion has made it less appealing and unoptimized.MPLS provides tailored traffic engineering capability that allows network traffic to be sent over non-standard routes or paths.

How many Types of Labels are there in MPLS?

There are three types of labels in the MPLS that are given based on the label operation that needs to be performed by the data packet.

1. Push

The Push label adds a new MPLS label to a data packet. When a normal IP packet enters an LSP, the new label or the Push label is the first label on the packet. This label contains information that makes this packet an MPLS packet.

2. Swap

The Swap label replaces the label with a new label. When an LSR does a multiprotocol label switching lookup, the lookup gives the label switched path next hop information along with the numeric identifier for the next segment in the label switched path.

3. Pop

The Pop label removes the MPLS label from a data packet. This is typically done at either the penultimate or the final router. The whole purpose of the labels is to ensure that the data packet is managed efficiently and takes the optimum path.

The importance of the label ends as the transmission over the network is complete. The destination address should not receive any sort of label as this may indicate that the message has been corrupted or altered against routing norms.

What is MPLS in Computer Networking?

In computer networking, MPLS is a routing method that gives data packets direction on which path to take to reach their destination address. This is done by assigning each data packet a label in the IP header which gives routers information they can use to find the next router and ultimately reach their end destination.

In terms of security, MPLS is considered a secure means of transporting data over the network. Not only secure, but another key advantage is that you will not be concerned about the completeness of data that you send over the network.

MPLS can be expensive in the case that there is data congestion, but its positive characteristics have made it an enterprise level solution in the past and still continues to remain in service today.

An MPLS link is a private link or a private network between data centers and connected offices.

Organizations and enterprises prefer to use MPLS because it is a well known technology and has been around for a while. It is continued to be used because of the fact that there is no data packet loss, it is reliable, maintains high availability and is secure.

On the downside, an MPLS link can be expensive. It’s installation is complex compared to some modern SaaS software that require minimal setup.

Which Layer is MPLS?

MPLS is an interesting concept and technology not only because of the benefit it brings but also because of the way it works.

There is particular interest and in some cases confusion when it comes to deciding if MPLS is a Layer 2 (Data Link Layer) or Layer 3 (Network Layer) service. Unfortunately for people who like to categorize things neatly, MPLS doesn’t fit nicely into the OSI seven-layer network hierarchy. To settle the debate, some people have classified the MPLS is Layer 2.5.

One of the major benefits of MPLS is that it places a divide between forwarding mechanisms from the data-link service that is the underlying layer. In simpler words, MPLS can potentially be used to create forwarding tables for the data packets for any underlying protocol.

In particular, the MPLS routers create a label-switched path(LSP) that is based on the criteria in the FEC (Forwarding Equivalence Class). MPLS forwarding can only happen when a LSP has been determined. LSPs are single directional which translates to return traffic being sent over a different LSP.

What is MPLS Connection?

An MPLS connection is a virtual path that is used to transport traffic in the form of packets to their destination address. MPLS connections are single directional meaning that MPLS connections allow data to flow in only one direction between two network endpoints.

MPLS works by adding a label to the head of each data packet and sends it over the network.

MPLS connections are signaled established endpoints. MPLS connection state is ensured at each node in the network path, and encapsulation or compression techniques are used to transport data across the connection.

What is Fec in MPLS?

In MPLS, Fec is a commonly used term that stands for forwarding equivalence class. Fec is used to describe a set or group of packets that have the same characteristics that can potentially be forwarded the exact same way. This means that the packets are bound to the same MPLS label.

An example of Fec in MPLS include data packets where the destination IP has the same prefix. Another example of Fec is multicast of packets that are part of a specific multicast group. Also, packets that are processed in the same mode depending on the IP DSCP field or the process.

What is an MPLS Router?

An MPLS router is a router that is capable of implementing multi protocol layer switching.

MPLS combines the performance and abilities of the data link layer switching with the proven scalable nature of the network layer routing. MPLS empowers service providers to deal with the challenge of unprecedented growth in network usage while giving the chance to differentiate services without sacrificing the existing infrastructure in terms of the network.

The MPLS architecture is really flexible and can be used in any combination of the data link layer technologies. MPLS support is given for all network protocols, and scaling is possible to a great extent.

What is IP MPLS?

IP MPLS or IP/MPLS or MPLS are terminologies used to describe the same thing; Multi Protocol Label Switching. The IP stands for Internet Protocol in IP MPLS. These terms may be used interchangeably.

In the case of IP routers, data packets first need to be processed and checked for their source and destination addresses. This is done so that the router may use its control function to find the most optimized path in its routing table for the data packets.

To reduce the time taken for this process, the IP packet contained a header label to fasten the data transfer as a whole.

MPLS link can be thought of as the link between data warehouses and branch offices. Companies generally do not manage the MPLS link on their own, instead, they enlist service providers who can manage, maintain and ensure that the network is available and performs as intended.

Companies are now slowly shifting away from MPLS to other technologies like cloud based applications or SaaS. In the case that traffic becomes backhauled, MPLS becomes more expensive and adds to the cost that an organization has to bear.

This, among other reasons including better options for a better price, has prompted companies to find alternatives to the MPLS link.

Is MPLS faster than VPN?

Most of the time MPLS is faster than VPN. This is mainly because the MPLS is designed to be faster.

The main thing that can speed up an MPLS is its labelling function. The MPLS labelling function provides provisions that don’t require individual routers to do an IP lookup.

Additionally, VPNs are generally spread out and are part of a larger network. MPLS on the other hand are more contained and mostly smaller.

VPNs are also slower since each data packet and piece of information needs to be encrypted before transmission over the network. This encryption and decryption takes time which the MPLS doesn’t need to worry about.

What is MPLS VPN Connectivity?

MPLS VPN connection is one form of VPN infrastructure that makes full use of the multiprotocol label switching techniques to deliver its VPN services. The MPLS VPN connection is a set of multiple MPLS-based VPN technologies that gives the capability to use multiple protocols and tech for making and managing communications in a VPN environment.

Enterprises need to deploy MPLS VPN of dynamically converged traffic. There is a genuine need for an advanced protocol that can facilitate converged applications and multimedia traffic.

A single commercial internet connection usually comes up with capacity limitations that prevent businesses from taking full advantage. This connection doesn’t have enough capacity to support various apps. If enterprises buy and maintain multiple connections to achieve the required capacity during peak usage hours, they will add costs and complexity at the end.

For these requirements, the value of something like an MPLS VPN is clear in that additional security and quicker routing for information being transmitted over the network.

What is the Difference Between SD WAN and MPLS?

Unlike regular WAN, SD-WAN provides a software-defined WAN which means that people are not managing the network, software is.

In terms of security, SD-WAN is the clear victor. It allows organizations to include their security policy at the network architecture level. It is also less costly and is not subject to strain if the network expands geographically.

MPLS has its own advantages. One of the most important being that there is no data loss when the packet is transmitted over the network. It also allows packet prioritization meaning that important data will reach the destination account even if fewers priority packets have to be dropped due to traffic congestion.

What is the Difference Between WAN and MPLS?

WAN stands for Wide Area Network and is the conventional way to provide internet access over large distances. People and well trained staff are really the ones who are there to configure the network. It’s performance does not particularly stand out.

MPLS on the other hand stands for Multiprotocol Switching Label. MPLS is primarily used to make the network more efficient as a whole by optimizing the transmission of data packets over the network. It’s performance stands out not only in terms of its speed, but also in security and availability.

What is the Difference Between VPN and MPLS?

VPN is a different network placed on top of a computer network. VPN uses cryptography for tunnelling protocols which it then uses to provide high level security.

VPN is mainly used when you want to access resources on the network that are not available to you from your current IP address or you want to have a level of anonymity over the network.

MPLS is operational between the Data Link Layer and the Network Layer. MPLS gives directions and transports data from one network node to the next.

MPLS is used by larger, enterprise level clients to forward data and manage traffic over the network.

Is MPLS Still Used?

Yes, MPLS is still used even today.

While it is not of any use to most end consumers, it is primarily used by larger clients at an enterprise level. These larger clients prioritize infrastructure that is reliable and secure.

MPLS ticks these boxes and more. But new entrants in the software market and the constant improvement of technology have raised the question whether MPLS will still be used or not.

Since mainly enterprise level clients are using MPLS, we can assume that it will be some time before there is a complete shift. Enterprise clients generally prioritize technology that has been working for them for a while.

We can expect there to be a hybrid shift where enterprises incorporate other technologies while still using MPLS. Gradually, they can then decide which one is better for them and map out a smoother transition.

Who Uses MPLS?

MPLS is mainly used by organizations and enterprises who are of high value and need performance.

Before software as a service (SaaS) took hold in the form of cloud based applications like Google Docs, Salesforce, companies relied on MPLS to operate applications from servers in secluded data centers.

There are several reasons that MPLS is still in use. These include high up time, high speeds, improved security, better bandwidth management, and traffic prioritization to mention a few.

As technology has improved, enterprise grade internet solutions have improved drastically as well. While the case for MPLS to become obsolete is gaining favor, the technology is here to see at least for the foreseeable future.