William Herrin Sent: Tuesday, July 21, 2020 8:21 PM
On Mon, Jul 20, 2020 at 9:57 PM Mark Tinka <mark.tinka@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