Have you ever ordered something on an international website and watched as that package makes stops across countries and at different cities within your country? Well, that’s close to how an IP routing works too. When a router receives a data packet from another router, all that it knows is the next stop and not the final destination. Based on this information, every router has to make an intelligent decision as to how that packet will be routed to the next stop in the best possible way. It does this by looking up the routing tables to find the shortest possible path. This process is done at every stop and by every router until the packet reaches its final destination. Though this sounds complicated, in reality, everything happens within a fraction of a second. But that itself can be long for time-sensitive applications like live video streaming. One possible solution to speed up this routing is to use predetermined and efficient routes that don’t require the additional lookup time, and this is where MPLS comes in handy.
What is MPLS?
Multiprotocol label switching, or MPLS for short, is a routing mechanism within a telecommunications network. These routers direct data from one node to another based on the short path labels instead of the relatively longer network addresses. The obvious advantage is that it avoids the need for complex lookups in the routing table, so communications tend to be faster. Since it also encapsulates the packets of varying protocols, it is called the “multiprotocol” routing technique.
Now that you know what MPLS is, let’s take a detailed look at its working.
How does MPLS work?
MPLS is not associated with any specific technology, rather it is an overlay technique that aims to improve performance and efficiency.
When a packet enters the MPLS network, a forwarding equivalence class (FEC) value is assigned to it by adding a small label to the packet. Every router within the network knows how to handle different FEC labels, so there is no need to do a header analysis each time. Instead, every router uses the label as an index to identify a new FEC for that packet.
In other words, MPLS creates a predetermined path to route traffic in the most efficient way possible based on the FEC label.
This mechanism gives routers the option to choose low-latency routes for certain applications like live video streaming so it is delivered faster to the destination when compared to the traditional routing mechanism.
Advantages and disadvantages
MPLS comes with a ton of advantages such as:
- Improved bandwidth utilization.
- Reduced congestion.
- Faster transmission.
- Better end-user experience.
- Security. Though MPLS does not offer encryption, it is still different from the public network and hence secure.
- Delivers performance for real-time traffic.
Though all this makes MPLS a great choice, it is equally important to understand its downsides before you make the right decision. Some of the drawbacks of MPLS are:
- Expensive as you’ll have to buy this service separately.
- Lack of global coverage as the existing ones tend to offer it through partnerships.
- Limited application in a cloud environment.
- Slower than newer technologies like SD-WAN.
- Setting up MPLS is time-consuming as you’ll have to set up all the fixed circuits. Likewise, making changes is also arduous.
Now that you know the pros and cons, it may seem obvious that you should switch to technologies like SD-WAN because it is cheaper and more flexible. But is this the right decision?
In 2013, Gartner raised an important question of the relevance of MPLS. This question was based on three emerging trends of that time, namely:
- Availability of a wide range of services for WAN architects and flexibility to choose based on budgets.
- Evolution of cloud computing.
- Growth of WAN optimization and path control technologies to bridge the gap between availability and performance.
At the end of this analysis, Gartner concluded that MPLS is not going to die anytime soon and it is going to be an integral part of hybrid networks.
Fast forward to 2019 and this analysis still holds. Many questions and debates have come up over the last few years on the relevance of MPLS, considering the phenomenal growth of SD-WAN. But the truth is, SD-WAN is not going to replace MPLS, rather it will only complement it well to provide a robust infrastructure for the organization.
Most organizations today have MPLS networks in place, so asking them to switch to SD-WAN is not the most optimal solution as most of them would prefer to augment rather than replace their existing and working platforms. This is why SD-WAN will play a complementary role and both the technologies together would help to improve the capabilities of the network.
If you’re wondering why in the world organizations don’t want to make the jump to SD-WAN, it is simply because MPLS is one of the most secure and stable techniques for transmitting data within a network. Though SD-WAN is transport agnostic, cheaper, and more flexible, MPLS offers business continuity and risk tolerance - both of which are critical for every organization.
Also, organizations such as hospitals and banks have invested heavily in MPLS networks and their need for a closed and private network makes MPLS highly relevant to them. In general, larger organizations are slower to adopt new technologies, and particularly when they operate in a traditional domain. Besides, it also makes financial sense to make the most of their investments, especially if the current infrastructure is working fine.
Another reason is that MPLS is a type of dedicated network access that is reliable and performs better than both broadband and wireless. In addition, organizations want to use multiple connection types for reliability and improved performance of their networks.
Due to these reasons, MPLS is neither dead nor is it going away anytime soon. And SD-WAN is not a meteor that is going to wipe away the MPLS dinosaur! Rather, both technologies will continue to evolve and complement each other to help organizations create robust, secure, and reliable networks.
Not going away anytime soon
In all, MPLS networks are a routing mechanism that moves data from node to node based on predetermined short-path labels. This mechanism was originally conceived and implemented many decades ago when the head office and its branch locations needed a secure and reliable way to communicate with each other.
With today’s cloud environment and the emergence of new technologies like SD-WAN, there is a big question about the relevance of the MPLS network. But the truth is, the MPLS network is not going away anytime soon because of a host of reasons and will continue to provide dedicated network access for organizations.
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