https://www.techtarget.com/searchnetworking/answer/In-WAN-evolution-is-software-defined-now-implied
The question is an interesting one: Is software-defined WAN now just the WAN? In other words, has the idea of software-defined become the norm to the point where we don't need to specify it anymore in relation to the WAN?
The answer: Not yet, but the day is coming. As SD-WAN chips away at the market, it's quietly redefining what network teams want from their WAN.
Keep in mind: SD-WAN has already pretty much supplanted most legacy WAN optimization, which is now routinely an add-on to an SD-WAN service rather than a standalone purchase. WANs that had optimizers are now mostly SD-WANs.
So, what about the rest of the WANs? The writing is on the wall.
Even for businesses with modest IT needs, it's increasingly difficult to get much done without network connectivity. As a result, tolerance for outages is decreasing.
For businesses setting up new locations, redundant and active-active WAN connectivity using whatever media is available -- coax, copper, fiber or wireless -- from whichever provider with automatic failover is becoming the baseline expectation. This also happens to be the baseline functionality of SD-WAN.
At the same time, WAN staff are getting harder to find as seasoned professionals retire and are not replaced by new workers. SD-WAN's emphasis on automation makes it a natural option for helping network teams adjust to network changes, expectations and innovation.
Note also, network as a service (NaaS) offerings mostly provide key SD-WAN functionality. The increasing number of organizations that now opt for NaaS have, in effect, shifted to SD-WAN. And, increasingly, traditional managed WANs are also managed SD-WANs. The MSPs see they can get more profit from networks that are easier to manage and more resilient.
Lastly, SD-WAN is coming for traditional WANs under the guise of cybersecurity initiatives. Whether it is firewall as SD-WAN node or SD-WAN as the anchor of Secure Access Service Edge, cybersecurity-led deployments are replacing legacy WANs with SD-WANs across industries and in organizations of all sizes.
So, although SD-WAN has not yet completely replaced legacy WANs -- and will not for many years to come given the slow rate of change in some organizations -- it is well on its way to doing so. Importantly, though, SD-WAN has changed what enterprises of all sorts expect from their WAN. Inevitably, eventually, any WAN will deliver at least the core of what is now considered SD-WAN functionality.
19 Apr 2023