[time-nuts] inexpensive fiber optic distribution

[Bob Bownes]

To pull this back to time nuts territory, this brings up the idea of simply
using traditional ethernet infrastructure, be it 100M/1G/10G/whatever at
the PHY layer to achieve distribution of 1pps. The infrastructure is easily
enough interfaced to, even a simple microprocessor can do it, using
switches allows for distribution with known characteristics. Not sure that
you'd need to climb up even into Layer 2, but if you do, that would allow
for identification of the sources by MAC address. You's still have to worry
about collisions I suppose. There are other networking technologies that
could also be used with less impact and better characteristics, with
infiniband (lossless, low latency) coming immediately to mind.

On Thu, Mar 21, 2019 at 11:03 AM Julien Goodwin <time-nuts at studio442.com.au>
wrote:

>
> The lock in is almost entirely vendor profiteering, optical monitoring &
> wavelength switching are standards (where implemented), but plenty of
> vendors use (almost always trivially bypassable) lock-in to sell SFPs
> they rebrand from the same OEMs at up to 100x markup.
>
> The folk in the big telcos (or in my case, big content providers) who
> run the global backbones have plenty of stories.
>

As one of the guys who has to make these decisions for a big company, I
have to pipe up in our defense.

It has very little to do with profiteering, though it is easily seen as
such. In reality, there are a number of vendors of transceivers out there
(or other similar parts) ranging from excellent to really horrible. The
'lock-in' is to restrict the pool to those that have been qualified and
tested. This vastly reduces support and service hassles on both ends of the
phone call. The incremental revenue on a transceiver of, in one case I can
document, of about $600, even when multiplied by the number required for a
full system, isn't even in the decimal points of the total cost of the
system, which can easily exceed $3-4M.

Bob