[time-nuts] inexpensive fiber optic distribution

[jimlux]

While researching this for a radio telescope, I found amazingly 
inexpensive (<$10) fiber optic transceivers for 1Gbps sorts of rates..

They take a standard singlemode duplex fiber and have a pinout suitable 
for plugging into a Cisco, etc. switch. Apparently, there's some 
internal programming which sets the hardware for the kind of switch, 
rates, etc..  fs.com has a generic ASIC inside the adapter which can be 
reprogrammed for whatever formatting, compatibility etc is needed. The 
astronomers were saying that at Berkeley, they bought a box for a few k 
which allows them to reconfigure the transceivers.


Something like this:
https://www.fs.com/products/12622.html

Data sheet here: https://img-en.fs.com/file/datasheet/sfp1g-lx-31-10km.pdf

and a 10 meter patch cable is $5
https://www.fs.com/products/40203.html

This is sort of "old news" in the networking world (the SFP form factor 
was defined in 2001)


It seems like you could probably figure out how to interface to these 
things and use them to distribute timing signals.

I'll be talking to the radio astronomers tomorrow again, and I'll see 
what I can find out about interfaces. I suspect they do NOT use them for 
conventional networking - they're all about running lots of bits from 
antennas into large multichannel correlators/beamformers.

They're buying these things by the dozen.