Patton OnSite 2701A/I, User Manual

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Introduction 62
OnSite 2701A/I E1/T1 Ethernet Bridge (NTU) User Manual 8 • SNTP Client Configuration
Introduction
The Simple Network Time Protocol (SNTP) Client webpage contains the configurable parameters for either
setting up the SNTP client or, in the absence of an SNTP server, setting the internal clock.
If you plan the use of an SNTP server, you will configure the ‘SNTP Client Mode Configuration Parameters’
and ‘SNTP Client General Configuration Parameters.’ If you are not accessing an SNTP server, you can con-
figure the system clock for a calendar clock setting.
Configuring the SNTP Client
The “SNTP Client Mode Configuration Parameters” section is for selecting the synchronization mode and
entering the IP address of the SNTP Server. With the “SNTP Client General Configuration Parameters” sec-
tion, you will select the time zone and set the transmit packet timeout period, retries, and polling period.
SNTP Client Mode Configuration Parameters
In this section you configure the synchronization mode and enter the IP address of the SNTP server. The
OnSite supports three synchronization modes: unicast mode, anycast mode, and broadcast mode. Unicast is a
point-to-point mode. Anycast is a multipoint-to-point mode. Broadcast mode is for use when the SNTP server
is on the local network, that is, the same subnet as the OnSite device.
When Unicast mode is enabled, the OnSite sends a request to the server designated in the field containing the
SNTP server’s IP address. (See figure 44 .) This is a point to point communication link. The OnSite device
requests from one server. The server sends the timing information directly to the OnSite. When disabled, the
OnSite device does not send any requests to any SNTP Server.
In Broadcast mode , the synchronization is with an SNTP server on the local network. Since NTUs do not for-
ward broadcast IP addresses, the SNTP server and OnSite device must be on the same subnet.
With Anycast mode , the OnSite device’s SNTP client sends a request to a designated broadcast address. One or
more SNTP servers may reply with a unicast message to the OnSite. The OnSite communicates with the server
first responding. After this point, the OnSite device operates in unicast mode. When
Anycast is enabled,
Unicast is automatically enabled and the IP address of 255.255.255.255 is in the SNTP server’s IP address
field. Anycast takes precedence over Broadcast mode.
The field Configured IP Address of SNTP Server: is the IP address of the dedicated unicast server that the SNTP
client will use for synchronization.
Figure 44. SNTP synchronization and server IP address configuration