Why is SD-WAN better than MPLS?

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There was a time when someone asked a network architect to implement a high performing wide area network (WAN), the only answer used to be Multiprotocol Label Switching (MPLS). However, with changing time the answer to this question has also changed. But, why is SD-WAN better than MPLS? What are different advantages it offers? What would you choose between the two? Read through the article to get answers to all these questions.

MPLS v/s SD-WAN: The complete guide to understanding which works best for your needs

In a modern network, Software Defined Wide Area Network (SD-WAN) is gradually proving to be an effective alternative to MPLS and that too for a variety of reasons. It comes at a lesser cost, is more secure, flexible, and provides superior performance. SD-WAN also helps to protect your network from vulnerabilities that MPLS is unable to. These are a few reasons why the industry has witnessed a sudden spike in the demand for SD-WAN over MPLS in recent years.

What is MPLS?

Multiprotocol Label Switching (MPLS) networks are built in a way to direct traffic via short path labels instead of network addresses through a network. This results in the quick and efficient delivery of traffic to its destination. Organizations need to install physical MPLS circuits at every connected site in order to make full use of MPLS. In turn, these circuits isolate the traffic from the rest of the internet between these sites by implementing an MPLS virtual private network between them.

The Hits

Organizations commonly use MPLS as their preferred choice for network connectivity as it offers a number of benefits such as performance and reliability. These dedicated MPLS circuits are pretty useful in latency-sensitive applications to provide better performance in network connectivity. In addition to this, there are some mission-critical applications that need a high level of reliability that only MPLS can offer.

The Misses

With these advantages, there are some obvious flipsides which are associated with MPLS as well. This is primarily because of the fact that it needs physical links to be installed at each site. This results in high Capex making it infeasible for organizations to deploy enough in order to meet the organization’s network needs. Also, as it involves physical links to be installed at each site, the ease of expansion is pretty low with MPLS networks. This also results in poor scalability in case the bandwidth needs to exceed beyond an organization’s capacity of existing links.

What is SD-WAN?

Software Defined Wide Area Network technology accomplishes the organization’s need of implementing a high-performing and reliable WAN. It aggregates several transport media and routes the traffic optimally over the available transport links like mobile networks, broadband internet, and in some cases even the MPLS circuits. In an application that is sending traffic over the SD-WAN network, only a single network pipe becomes visible. SD-WAN identifies the application once the traffic is sent over this pipe and then it applies application-specific routing policies. On the basis of the latest status of available links and these routing policies, the traffic is routed to its destination over the best available choice of link. This enables organizations to ensure that latency-sensitive applications are catered to the kind of network performance they need and network bandwidth is not wasted on the less important traffic.

The Hits

There are numerous advantages that SD-WAN comes with making it a better choice for a corporate network. The first and foremost is that it identifies the application that creates the traffic and then uses application-specific security and routing policies in order to optimize the network performance. It also helps in decentralizing the networking functionality as SD-WAN appliances can be installed at each physical location. Aggregating the transport media optimizes the routing of latency-specific applications and thus results in superior performance. In case any particular link is not available or causing poor performance, SD-WAN is equipped to adapt as it uses multiple transport media. And that’s the very reason that organization can add incremental bandwidth as per its requirement resulting in it being a scalable solution to the organization’s network needs. Also, as it does not require any physical transport media to be installed, it is easier to deploy and new locations as well.

The Misses

SD-WAN comes with its part of improvement areas as well. As it is implemented as a network of appliances, it requires an SD-WAN solution to be deployed at each site and the cloud for the maximum impact. Also, though there are secure solutions available yet integrated security is not available in all SD-WAN solutions.

Benefits of SD-WAN over MPLS

If you have read through the article till now, you would have understood the fact that both come with their set of pros and cons. Now the ultimate question that arises then why would you prefer SD-WAN over MPLS when it comes to the networking needs of your organization. Here is an exhaustive list that will help you arrive at the conclusion:

Cost-Effectiveness

The biggest flipside with MPLS is the cost at which it comes at. In case your organization requires high bandwidth, the router and the circuits it requires will cost a bomb.
On the other hand, SD-WAN permits your network to utilize several high bandwidth but less expensive transport media such as fiber, 4G, etc at the same time. Hence aggregation of different connections will result in higher performance at a way lower cost in the case of SD-WAN.

Agile Network Performance

SD-WAN networks always send your traffic over the internet circuit which has the fastest route and limits the low priority traffic in real-time in case of multiple ISP connections. Whereas for MPLS, it is not possible to act in such a manner. There are a singular network and your CoS (Class of Service settings are static in nature and do not have the ability to fine-tune in real-time.

Enhanced Uptime

SD-WAN allows you to integrate multiple ISP & WAN connections at one site and hence results in flawless and continuous circuit redundancy for WAN throughout all the ISP networks and circuit types. On the other side MPLS networks experience failover to another internet connection.

Freedom from ISP

MPLS networks have a dedicated relationship with their ISP and it binds you to have the same MPLS provider on all the sites. And that’s the reason the ease of switching the ISP provider is very low in MPLS and you would need to put in a whole lot of effort in case you wish to change it. SD-WAN, on the other side, is ISP agnostic and you never feel imprisoned by your ISP. You can modify it very easily at any site.

Similar treatment for all the sites

As an organization, you would have felt that with MPLS networks, there are a few sites that do not qualify to be a good fit to be a part of the MPLS network. The reason can be that they are small and do not justify the cost requirement or these sites may fall in the non-serviceable area for your MPLS provider. In such a case, you are forced to experience a below-par network performance as the traffic is run over IPsec VPN on these sites in the case of MPLS. SD-WAN provides a similar kind of treatment for all sites as it does not matter which provider you are using in case of SD-WAN.

The Verdict

If as an organization, you use a number of real-time applications such as video conferencing or remote desktops or phone calls, you might still want to go with MPLS as SD-WAN with its multiple advantages still uses public internet which may cause latency, jitter, and packet loss which is not an optimal solution to real-time applications.

However, most organizations use cloud-based applications these days on platforms such as Amazon Web Services or Google Cloud or Microsoft Azure or AWS. The SD-WAN box at the site sends the traffic to the cloud gateway and which in turn connects to the cloud applications. It keeps on searching for a better circuit but leaves your cloud sessions up and running all this while. That means that SD-WAN proves to be a good deal in the case of cloud-based applications even if you need it in real-time.

Additionally there are some SD-WAN providers which have the facility of direct connections to some major cloud service providers out there. This results in immediate connection with less packet loss and latency and in turn a better user experience at the end of the day. While some MPLS providers also offer this kind of service but that does not keep the session constant with the cloud gateway.

So in the case were wondering why is SD-WAN better than MPLS, you would have found your answer through this article by now. Needless to say that SD-WAN comes as a complete package and provides an agile and flexible networking experience which include aggregation of WAN links, acceleration of applications, NGF (Next Generation Firewall) security, direct connection to major cloud providers, ISP independence etc. While comparing the two, SD-WAN comes out as a clear winner by some margin on the parameters like performance, network security and cost.