Error in NTP status of SX20

[Shinichiro Go]

The following is displayed and NTP does not synchronize.

Connection to NTP server not yet established.
This might mean that we have not yet had the time to establish a connection,
that the NTP server is unavailable, or the the configured NTP server are not valid host names or addresses.
If this message presists, please verify your NTP configuration, and that the server is reachable.

The OS is CE 8.3.0.
What should I do?

[Joe Vallender]

Might there be a firewall or router access list blocking the ports needed for NTP traffic?

[Patrick Sparkman]

What NTP server are you trying to use, is it internal or external?

What if you try Google: time.google.com or 8.8.8.8?

[Nick Halbert-Lillyman]

If you are registered to CUCM, check the SX20's "Phone NTP source" (it's set in the Device Pool).

TP endpoints only support NTP sources that are set to "Unicast" rather than "Directed Broadcast" in CUCM.

[Wayne DeNardi]

An issue for NTP can be caused if you specify a DNS name for the NTP server (ie 0.ntp.tandberg.com) and you don't have any DNS servers configured on your endpoint.

The endpoint won't be able to resolve the DNS server name to an IP address, so won't be able to connect to it to get the time.

[Shinichiro Go]

Thank you everyone.

Check if traffic is restricted by FW.

In addition, SX20 is not registered with CUCM, and it is operating independently.
Is it possible to change the NTP Source by accessing the SX 20 with the GUI?

[Patrick Sparkman · Accepted solution]

You can change the NTP address using the web interface under Configuration > NetworkServices > NTP. 

SX20 CE8.3 Admin Guide