[c-nsp] Devil's Advocate - Segment Routing, Why?

[Mark Tinka]

On 19/Jun/20 10:40, Saku Ytti wrote:

> Maybe this is fundamental and unavoidable, maybe some systematic bias
> in human thinking drives us towards simple software and complex
> hardware.
>
> Is there an alternative future, where we went with Itanium? Where we
> have simple hardware and an increasingly complex compiler and
> increasingly complex runtime making sure the program runs fast on that
> simple hardware?
> Instead we have two guys in tel aviv waking up in night terror every
> night over confusion why does x86 run any code at all, how come it
> works. And I'm at home 'hehe new intc make program go fast:)))'
>
> Now that we have comparatively simple compilers and often no runtime
> at all, the hardware has to optimise the shitty program for us, but as
> we don't get to see how the sausage is made, we think it's probably
> something that is well done, robust and correct. If we'd do this in
> software, we'd all have to suffer how fragile the compiler and runtime
> are and how unapproachable they are.

So this brings back a discussion you and I had last year about a
scenario where the market shifts toward open vendor in-house silicon,
sold as a PCI card one can stick in a server.

Trio, ExpressPlus, Lightspeed, Silicon One, Cylon, QFP, e.t.c., with
open specs. so that folk can code for them and see what happens.

At the moment, everyone is coding for x86 as an NPU, and we know that
path is not the cheapest or most efficient for packet forwarding.

Vendors may feel a little skittish about "giving away" their IP, but I
don't think it's an issue because:

  * The target market is folk currently coding for x86 CPU's to run as
    NPU's.

  * No one is about to run 100Gbps backbones on a PCI card. But hey, the
    world does surprise :-).

  * Writing code for forwarding traffic as well as control plane
    protocols is not easy. Buying a finished product from an equipment
    vendor will be the low-hanging fruit for most of the landscape.

It potentially also has the positive side effect of getting Broadcom to
raise their game, which would make them a more viable option for
operators with significant high-touch requirements.

As we used to say in Vladivostok, "It could be a win win" :-).

Mark.