DMVPN: The Original SD-WAN
While not exactly a cutting-edge technology anymore, I recently gave a small introductory training presentation on the underpinnings of DMVPN and how it has the potential to help to solve labor-intensive S2S VPN management. The ability for phase 3 DMVPN direct spoke-to-spoke communication helps pit a serious business case of utilizing BYO Internet circuits up against costly, slow MPLS solutions. Further, I can easily imagine that some SD-WAN organizations already bootstrap their core product using solely DMVPN backed by an MPLS core.
My deck of 24 slides SlideShare presentation