Edge-Core ECS4660-28F, Руководство по управлению, Страница: 595 / 2020

C
HAPTER
14
| Basic Administration Protocols
PTP Configuration
– 595 –
C
ONFIGURING
G
LOBAL
S
ETTINGS FOR
PTP
Use the Sync > PTP (Configure Global) page to set the operating mode,
adjustment to received Sync messages, the preference level used to select
the master clock, and clock synchronization domain to which the switch is
assigned.
CLI R
EFERENCES
◆
"ptp mode" on page 963
◆
"ptp adjust" on page 961
◆
"ptp priority1" on page 965
◆
"ptp priority2" on page 966
◆
"ptp domain-number" on page 962
◆
"ptp e-latency" on page 962
◆
"ptp in-latency" on page 963
C
OMMAND
U
SAGE
◆
When PTP mode is set to boundary clock, the delay mechanism is
determined by the interface setting for this parameter (see
"Configuring Interface Settings for PTP" on page 598 ). When set to
transparent clock, the delay mechanism is determined by message
exchanges with other clocks in the PTP domain.
P
ARAMETERS
These parameters are displayed:
◆
PTP Mode – Sets the operating mode to one of the following options:
■
Disable – Disables PTP on the switch. (This is the default setting.)
■
Boundary – A boundary clock can have multiple network
connections and can accurately bridge synchronization from one
network segment to another.
Setting the switch to boundary mode allows it to participate in the
selection of the best master clock. If no better clock is detected, it
will become the grandmaster clock within its PTP domain, and the
parent clock to all connected devices. However, if the best master
clock is found to be a another clock connected to the switch, the
switch will synchronize to that clock as its child, and then acts as
the parent clock to devices connected to other ports. After initial
synchronization, the switch and connected devices exchange timing
messages to correct for time skew caused by clock offsets and
network delays.
■
Transparent – A transparent clock modifies PTP messages as they
pass through the switch, updating the time stamps to correct for
time spent traversing the network.
■
End-to-End – This method measures the residence time
required for PTP event messages to cross from the input port to
the output port, and adjusts the time stamp to compensate for
this delay. The value of the correction update and checksums
are specific to each output port and message since the residence