> William Herrin > Sent: Tuesday, July 21, 2020 8:21 PM > > On Mon, Jul 20, 2020 at 9:57 PM Mark Tinka <mark.ti...@seacom.com> > wrote: > > Suffice it to say, to this day, we still don't know what SDN means to > > us, hehe. > > Hi Mark, > > The Software Defined Network concept started as, "Let's use commodity > hardware running commodity operating systems to form the control plane > for our network devices." The concept has expanded somewhat to: "Lets use > commodity hardware running commodity operating systems AS our network > devices." For example, if you build a high-rate firewall with DPDK on Linux, > that's now considered SDN since its commodity hardware, commodity OS > and custom packet handling (DPDK) that skips the OS. > The higher level takeaway would be: "Modularity based on abstraction is the way things get done” − Barbara Liskov
Abstractions -> Interfaces -> Modularity This applies at the individual device level as well as you described above, however I'd say that application of these principles at the network-wide level is also very beneficial to service providers, (Device -> Network -> Service -> Product -> Offer). This vision was first realized by AT&T in their ECOMP framework which (along with Open-O) is now morphed to ONAP. This idea has now been adopted by many service providers as well as commercial products. adam
