Calnex Sentinel - Page 31

Using Sentinel
CX3001 v7.0 © Calnex Solutions 31
calnexsol.com |
Poll
Poll rate selection. The poll rate can be configured as 1 packet every 2
n
seconds, where n=0 to 17. This gives a max poll rate of 1 packet per second
and a minimum poll rate of 1 packet every 36.4 hours.
Version
NTP version. Sentinel supports versions 1 through 4.
Normalize delays
When On PDV samples are normalized relative to first delay sample so that first
PDV sample has zero value. In this mode delay variations are displayed on PDV
graphs.
When Off – no PDV normalization is done, so PDV graphs display absolute
delays (including propagation delay, time offset between Server and Sentinel,
and other time inaccuracies in the system). NTP 2 Way TE will be calculated
when Normalize delays is Off
Network Mask Limit
User defined 2way Time Error mask value
Selection
This window will appear only when the PDV Option is enabled. For each installed Packet module, a selection
algorithm can be applied to only one type of packet delays (FWD/REV/PD - Forward, Reverse or Path Delay) or to
none.
Selection algorithm contains three components which can be set up independently.
By default, the settings are for ITU-T G.8261.1 FPP testing.
Window parameters
The user can choose one type of window: window sliding by samples or window sliding by time.
When the Window is sliding by samples, it always consists of a constant number of samples but time interval
between first and last sample in the window is varying. Window size and step are defined in terms of samples
number.
When the Window is sliding by time, it contains set of samples in which time difference between last and first
samples is not greater than given window size; Window step is also given in terms of time.
Window step to window size ratio determine overlapping rate. Normally, window step should not be greater than
window size.
Selection method
Selection is a procedure of picking packets from a window which conforms to a given constraint. The user can
select one of two possible selection types which determine constraints being used: Band selection and Cluster
range .