1. Is SD WAN here to replace MPLS?
Are the two technologies alternative incarnations of the same beast? Decidedly not. SD WAN is an overlay technology, whereas MPLS is simply an option for the underlay that provides the connectivity for an SD WAN. To compare the two just isn’t logical. SD WAN may be the latest, greatest system, but it can’t function without an underlay.
If SD WAN won’t replace MPLS, will it impact it in any other way? We believe that a decline in MPLS will follow. However, there’s plenty of life left in the old MPLS dog yet. Let’s look more closely at the likely threat from SD WAN.
(i) Cost and Performance
SD WAN won’t itself kill off MPLS, but it might make it easier for businesses to use alternatives to MPLS for at least some traffic. Could we soon be moving our traffic from MPLS to the internet? Maybe. But the internet would have to be cheaper and better. This depends on your situation.
If you run everything from the cloud, you might be less bothered about MPLS performance. However, if you run a latency-sensitive application over high-traffic circuits, you might feel the internet isn’t up to scratch.
What if you’re an international company with multiple sites outside the UK, then you’re sure to find ways of saving money by moving traffic from MPLS to locally sourced internet. But, if most of your sites are UK-based, then this won’t apply. MPLS circuits are barely (if at all) any dearer than the UK internet.
(ii) Hybrid networks
There is a cheaper alternative to MPLS - through using a hybrid network - combining multiple technologies (MPLS, VPLS, Internet) from multiple carriers.
So, Hybrid Networking may well be a driver that will contribute towards the decline of MPLS.
(iii) SaaS applications are encouraging a move to more internet-focussed networks.
With cloud applications and platforms being accessed via the internet, businesses are examining the best way of accessing these from remote sites. Conventionally,, SaaS application traffic from branch office users has traversed the MPLS to the HQ and then broken out to the internet. This adds further latency, thus restricting throughput and performance.
Typically, SD WAN devices are designed to recognise this traffic and break out to the internet directly from the remote site. This reduces traffic over the MPLS, speeding up its decline.
However, the MPLS providers have not been idly ‘fiddling while Rome burns’. They have been working to create private connections with the associated Class of Service into the Cloud Provider’s networks. This gives remote sites direct connectivity over the secure MPLS network.