From Milliseconds to 26 Nanoseconds: How a $20 eBay SFP Module Beat My Entire NTP Setup. It's a special SFP multicasting PTP frames to the network!
https://austinsnerdythings.com/2026/04/26/ptp-osa5401-26-nanoseconds-raspberry-pi/

From Milliseconds to 26 Nanoseconds: How a $20 eBay SFP Module Beat My Entire NTP Setup - Austin's Nerdy Things
Welcome to Austin’s Nerdy Things, where we spend years chasing nanoseconds that nobody asked us to chase. Five years ago, I started this blog by building a microsecond-accurate NTP server with a Raspberry Pi and PPS GPS. Then I went simpler – a $12 USB GPS for millisecond-accurate NTP because ease of use matters too. […]







