Well this chain went on quite a ways and I read Scott's posts. I will agree that originally it was for larger companies.. Facebook uses SD WAN instead of MPLS. However, SD WAN is a good alternative for MPLS actually.
I agree it does make more sense with bigger companies, however this is how it works and why it is advantageous.
SD Wan like Aryaka allows you to choose the best Edge provider in your geographic regions. Then the SD Wan provider has NTN interfaces with all the carriers and with the shortest amount of hops brings the traffic back onto their backbone.
However, you could very easily build your own solution. Simply build out strategic data center locations nation wide and geographically have your end user sites VPN to the data center and connect your data center over their backbone or set up Gig Wave circuits between sites.
This is becomming the standard for multi-site scenarios. Anyone who has 4 or 5 sites and wants to use a single carrier for MPLS can attest that certain sites when they price out are more expensive because they are offnet. SD WAN is providing a realistic alternative for this while keeping latency low and being able to tag packets for priority for voice and Video.
