Re: questions asked during network engineer interview

[Robert Raszuk <robert () raszuk net>]

Bill,

> 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."

That's not exactly the real beginning ... the above is more like oh where
do we plug this SDN into and how do we sell it :)

The last churn of SDN as I recall and as explained by Nick McKeown was an
attempt to open innovation into networking ... allowing one to invent
protocols at will as well as setup forwarding tables with arbitrary
switching/routing capabilities as student or operator would only like to
imagine.

That's when the OF was born (with various versions of it) to allow the
hardware and software decoupling.

Well I guess that experiment can be considered as completed today :)

Best,
R.


On Tue, Jul 21, 2020 at 9:22 PM William Herrin <bill () herrin us> wrote:

> 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.
>
> This is happening a lot in the big shops like Amazon that can afford
> to employ software developers to write purpose-built network code.
>
> Regards,
> Bill Herrin
>
>
> --
> William Herrin
> bill () herrin us
> https://bill.herrin.us/