Microsemi SyncServer S300 User Manual page 41

uppermost 18 bits of the time stamp fractional component have value, indicating a precision
in the microsecond range.
root distance (also root delay): This is a measure of the total round trip delay to the root of
the synchronization tree. A typical value for a SyncServer operating at stratum 1 would be 0
since the SyncServer is a root of the synchronization tree For other stratum levels, an appro-
priate value is displayed. Depending on clock skew and dispersion, this value could be pos-
itive or negative.
root dispersion: This is a signed fixed-point number indicating the maximum error relative
to the primary reference source at the root of the synchronization subnet, in seconds. Only
positive values greater than zero are possible.
reference ID: This is a four-byte field used to identify the reference clock source. At ini-
tialization, while the stratum is 16, this field shows the progression of the NTP clock PLL. The
field will start with a value of INIT (may be displayed as 73.78.73.84, the ASCII decimal val-
ues). Once a peer has been selected, the clock may be stepped, in which case the reference
ID field will change to STEP (or 83.84.69.80). Once the PLL is locked, the stratum will be
updated and the reference ID will identify the selected peer. In the case of a SyncServer
operating at stratum 1, the reference ID will display the source for the local timing reference
1
(e.g., GPS , IRIG, FREE). In the case where the selected peer is another NTP server, the
reference ID will display the IP address of the server or a hash unique to the association
between the SyncServer and the remote server.
reference time (also reference timestamp): The time when the SyncServer last received
an update from the selected peer. Represented using time stamp format in local time. If the
local clock has never been synchronized, the value is zero. A time stamp of zero corresponds
to a local time of Thu, Feb 7 2036 6:28:16.000. This value is typically updated every 16
seconds for a locally attached hardware reference (e.g., GPS, IRIG) and in an interval of 64-
1024 seconds for a readily accessible remote NTP server.
system flags: These flags define the configured behavior NTP daemon running on the Syn-
cServer. The definition of the variables is provided.
kernel: The NTP daemon is enabled for the precision-time kernel support for the ntp_adj-
n
time() system call.
monitor: The NTP daemon is enabled its monitoring facility.
n
ntp: Enables the server to adjust its local clock by means of NTP.
n
stats: The NTP daemon is enabled itsstatistics facility.
n
auth: The NTP daemon is enabled itsauthentication facility.
n
jitter: Jitter (also called timing jitter) refers to short-term variations in frequency with com-
ponents greater than 10 Hz.
stability: Stability refers to how well the SyncServer can maintain a constant frequency over
time. It is usually affected by aging, environment changes, etc. The value is expressed units
of parts per million (ppm).
broadcastdelay: The broadcast and multicast modes require a special calibration to determ-
ine the network delay between the local and remote servers. Typically, this is done
1
The SyncServer S350i does not include a GPS receiver.
997-01520-02 Rev. F1..........................................................................
NTP - Sysinfo
Page 41