WESM zl Management and Configuration Guide WT.01.03 and greater

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Configuring the ProCurve Wireless Edge Services zl Module
Enabling Secure Network Time Protocol (NTP)
■ Host Mode—the Wireless Edge Services zl Module’s mode:
client—The module is associated with a resource which operates in server
mode. The module polls the server, but does not respond to polls from the
server. If the server sends valid NTP packets, the module may synchronize
with it.
server—The module allows itself to polled by clients that want to synchro-
nize with it. The module does not poll the clients.
active—The module is in a peer association with the NTP resource. That
is, both the module and the other resource can send and respond to polls.
■ Peer Mode—the mode of the other NTP resource in the association
The peer might operate in any of the modes described for the host mode.
If the mode is “unspec,” the Wireless Edge Services zl Module cannot
reach the peer.
■ Host Poll—the maximum interval between successive polls received from
the remote resource. To find this interval in seconds, subtract 1 from the
value listed and raise the new value to the power of 2. For example, if the
value is 7, the maximum interval in seconds is 64.
■ Peer Poll—the maximum interval between successive polls sent to the
remote resource. The interval in seconds is calculated from the value
shown as described for the host poll.
The Details screen also shows timestamps for the most recent NTP exchange:
■ Reference Time—the time at which the local clock was last set or cor-
rected, in 64-bit timestamp format.
■ Org Time—the origination time at which the request departed the client
for the server, in 64-bit timestamp format.
■ Receive Time—the time at which the request arrived at the server, in 64-bit
timestamp format.
■ Transmit Time—the time at which the reply departed the server for the
client, in 64-bit timestamp format.
By tracking timestamps for all NTP exchanges, the Wireless Edge Services zl
Module calculates the following:
■ Root Delay—a 32-bit signed fixed-point number indicating the total round-
trip delay to the primary reference source, in seconds with fraction point
between bits 15 and 16. Note that this variable can take on both positive
and negative values, depending on the relative time and frequency offsets.
The values that normally are displayed in this field range from negative
values of a few milliseconds to positive values of several hundred milli-
seconds.