[tommiegannert]

SDN just means reconfiguring things that used to be manually configured on-the-fly.

E.g. instead of your little server setting firewall rules locally, it tells the router what traffic to allow. That router, in turn, tells upstream about its needs, and so on. Or a server reports its load, and the routers do active load balancing. The hardware wires are still there, as always.

Re. hardware acceleration, I think the earliest form of this was moving the checksum computation [1] from the CPU to the network device, even though the networking device didn't really know about the protocol it was doing the checksum for.

In both, it's just about parallelizing workloads, the same we do with microservices at the upper levels of the stack. Natural progression of distributed systems, with fancy names attached.

[1] https://en.wikipedia.org/wiki/Transmission_Control_Protocol#...