Ptp; Ptp Global Settings - D-Link xStack DGS-3620 Series Reference Manual

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xStack DGS-3620 Series Layer 3 Managed Stackable Gigabit Switch Web UI Reference Guide

PTP

The Precision Time Protocol (PTP) system is able to synchronize the distributed clocks with an accuracy of less
than 1 microsecond via Ethernet networks for the very first time.
PTP is a technology that enables precise synchronization of clocks in systems. PTP is applicable to systems
communicating by local area networks supporting multicast messaging including Ethernet and UDP. PTP enables
heterogeneous systems that include clocks of various inherent precision, resolution and stability to synchronize to a
grandmaster clock.
The synchronization is divided into two processes. The Best Master Clock (BMC) algorithm determines the PTP
status (master/slave) of all local ports. The synchronization algorithm computes the clock offset between the master
and slave clock. There are two mechanisms, Delay Request-response Mechanism and Peer Delay Mechanism, for
measuring the propagation time of an event message.
The PTP system has three types of PTP devices, boundary clock, end-to-end transparent clock and peer-to-peer
transparent clock. Only boundary clock can participate in the selection of the best master clock.

PTP Global Settings

This window is used to configure the PTP function globally.
To view this window, click L2 Features > PTP > PTP Global Settings, as shown below:
The fields that can be configured are described below:
Parameter
PTP State
PTP Mode
PTP Transport Protocol
Unit
PTP Clock Domain
Number (0-127)
PTP Clock Domain Name
Click the Apply button to accept the changes made for each individual section.
Figure 5-132 PTP Global Settings window
Description
Use the drop-down menu to enable or disable the PTP state.
Use the drop-down menu to select the PTP device type of the Switch. The Switch
supports three PTP device types, Boundary, P2P Transparent, and E2E
Transparent. The default is E2E Transparent.
Use the drop-down menu to select the transport protocol that will be used for the
communication path. The default option is UDP.
Select the switch unit to configure.
Enter the domain attribute of the local clock. All PTP messages, data sets, state
machines, and all other PTP entities are always associated with a particular
domain number. The range is from 0 to 127. The default value is 0.
In a stacking system, each unit runs PTP independently, each unit could run in
the same domain or different domains.
Enter the domain name for a specified domain number.
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