Need a Time Server?

If you have contacted us because you need a time server, you can use our servers subject to the contraints discussed below. We offer three stratum 1 servers for time-setting for sites off-campus, and a tier 1 server for Purdue users. Our stratum 1 servers are part of the NTP Pool, and that service may provide a good option if you need more or other time servers, in addition to (or in place of) our servers. Other servers are listed at the time servers site.


We provide three NTP servers for use inside and outside of Purdue University. These consist of one stratum 1 time server (CDMA-based) for any Internet users, and two additional stratum 1 servers (GPS-based) for any users. A fourth (GPS-based) server is for internal Purdue use.

We make no guarantees about this service. The servers may go down at any time, or become unreachable to users outside Purdue, although that is unlikely. We will try to maintain reasonable availability, but any service is provided on an "as is" basis as a courtesy. We make no warranties about the accuracy of the time signal beyond our good-faith belief that it is as accurate as can be achieved using our stock hardware and software.

Access as a client

If you wish to use our time servers, we ask that you observe the following:


For users NOT AT PURDUE:

Authenticated Time

If you have need of authenticated time (using MD5, as defined in the NTP protocol) then we can exchange key information to enable this. Contact ntp-request@cerias.purdue.edu. We currently do not have autokeying set up on any of the servers.

Establishing your own server

Our Stratum 1 servers come as rack-mountable units with an external antenna. This is generally easy to set up. CDMA units work from cell phone signals, so anywhere inside where there is a good cellphone signal is appropriate. GPS units require an antenna mounted outside with an unobscured view of the sky.

Our servers have generally been simple to set up and maintain, with some running for nearly a decade.

Establishing your own time server might be a good move, especially if you need a secure time source, because you can run it inside your firewall. Cost for a system is generally a few thousand dollars for US customers. Options are available to get more precise local clock crystals for times when the external time source is unavailable, but that adds expense. For more details, you can visit EndRun Technologies, HEOL Design, and Microsemi Corporation for a range of possible NTP and PTP timing solutions.

Thank You!

We gratefully acknowledge the generous support from EndRun Technologies, Microsemi Corporation, and HEOL Design, as well as their great engineering and support.

For More Information

Lots more information on NTP, including the latest software, is available at http://www.ntp.org/.

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