Will SD-WAN replace MPLS?

• SDWAN -Software Define Wide Area Network.
• MPLS  - Multi-Protocol  Label Switching.

As you know that there are a lot of digital transformations happening in recent years and the things have been changing with rapid pace.Starting from the desktop websites to mobile websites and then from mobile apps to cloud apps, OTT media services.But the problem was with the network, its was designed on the basis of hops,device,source and destination based with no visibility to applications.The network was not application centric.

 

In order to meet the current business requirement enterprise network need to be more intelligent,cost-effective and with fast WAN deployments.That's why SDWAN solution came into picture to fill-up this gap.

Let's take an example, In picture shown below you can see a car dashboard. It was late 80's or 90's design which had basic information to reach from Point A to B.You can relate this to MPLS without SDWAN. MPLS will still be there for backbone connectivity.But this design will not meet today's business requirement.

              

                                                                                              Picture-1

Now let's take an example of below picture-2  here you have all features more visibility and you have apps to show which route is best to reach from point A to point B or it can do the re-routing of path based on the path scenario using analytics with AI machine learning driven models. Different  driving modes in city and off road. You can relate this with MPLS with SDWAN. At enterprise level for remote site,data center connectivity using overlay SDWAN solution will be more in demand.

                                 

  

                            

              

Picture -2 

Hope this visual comparison given you the basic idea about SDWAN and MPLS. MPLS is your engine, transmission and tyres on which your car is able to drive. So,its not MPLS vs SDWAN it is MPLS with SDWAN. MPLS provide the underlay network connectivity and SDWAN is a overlay technology (in picture 3) that runs over underlay and  SDWAN will add more intelligence to MPLS or tradition WAN or even internet/4G/5G. We should understand the technology first rather than following the commercial hype between vendors to promote the things.Its a expansions and bringing intelligence to your network.

Yes definitely it will be cost effective  as in traditional network if site has two link usually primary link will be active and second link will be standby.The network need to be designed accordingly.With SDWAN organisation will have flexibility to use both links with application centric routing.

                                                                             Picture-3

This certainly decrease the utilization  and bandwidth requirement on MPLS link and traffic can be offloaded to secondary internet/4G/5G links. Enterprises have to spend less on MPLS bandwidth upgrades for critical sites and on WAN optimization appliances.

Earlier enterprises does not have choice so they have to spend on MPLS circuit  as secondary link as well and they need to keep the same bandwidth as primary and that link will be on standby.And this will be the flat calculation like if site utilization is  50 Mbps then they have to go for 100 Mbps or have to choose the plan provided by service provider.

In above picture-3  there are two available transports MPLS and Internet.Considering the traditional network , primary  link will be MPLS as this has QoS with more secured private backbone connectivity to enterprise data centres. Secondary link will be internet which will be used as backup.With SDWAN we are adding intelligence to our network.With SDWAN both transport MPLS and Internet will be used to carry the traffic based on the intend or policy based application aware routing.By doing so internet overlay is also secured  and have more features like QoS ,security and tcp optimization.

Now enterprises have choice to use internet link as secondary link even they can combine two internet links and create a policy based application aware routing.Keep critical sensitive or back bone traffic on MPLS link.Some of enterprises security policies will be very strict like banking or insurance sector and they do not trust on public clouds.So it depends what is enterprise requirement as well.This is not true that it will slash the cost to 90% which usually SDWAN advertisements claims.But yes cost will definitely decrease by some percentage and network will be ready to work with today's business requirements.

Over all SDWAN is still evolving day by day will have more features in future and will be in more demand. Enterprises need to determine the business case for application type,application workload and choose the right tool to fit in their requirement.Stay connected to know more about SDWAN by keeping things simple by excluding the commercial and sales things which you will find a lot everywhere.