Stratum 1 NTP Deployment

Deploying a Stratum 1 NTP server with a Raspberry Pi and a GPS as a timing source.

Well, it’s done! I have a small RP2 acting as a Stratum 1 NTP Server using a GPS module with the GPIO input.

It’s been added the canadian cluster of NTP servers and has begun answering queries. The process was relatively simple with a few things to keep in mind :

The default repository do not hold a recent image of the NTPD image. You are better off downloading and compiling the archive yourselves.

Here is the GPS module for the Raspberry Pi A+/B+/2 : link

You might need an antenna to lock on to the GPS signal. Especially true if you are indoors. Depending if a GPS repeater is present, it might be impossible to get a lock anywhere else than the top floor of a building or a room with windows.

I made the mistake of ordering the old style of GPS module for the RP2. It does fit, but it’s a bit awkward and I need to get a GPIO riser so that the antenna isn’t hitting the USB/Ethernet connectors. For now, the GPS module is just not fully connected to the GPIO board. There might be 3 centimeters of the connectors exposed. Everything seems to be working fine but doesn’t look very clean.

Here is a small taste of what kind of devices seem to be hitting my server

ntp-traffic (

That’s a lot of cable modem/CPE devices. I wonder why ISP are not using internal servers. Seems like time is something you would want full control over.

Laurent Dumont
I route packets and juggle bytes