Users Guide

Message types
● Event messages: Timed messages with an accurate timestamp that is generated at both the transmit time and receive time.
○ Sync—Master sends a Sync message to distribute the time of the day.
○ Delay_Req—Slave sends a Delay_Req message to the master for end-to-end delay measurement, the request-
response delay mechanism.
○ Pdelay_Req—Link node A sends a Pdelay_Req message to measure peer-to-peer delay.
○ Pdelay_Resp—Link node B sends a Pdelay_Resp message to measure peer-to-peer delay.
● General messages: Do not require accurate timestamps.
○ Follow_Up—In a two-step clock, the master sends a Follow_Up message after sending the Sync message.
○ Delay_Resp—Master sends a Delay_Resp message to measure the end-to-end delay.
○ Pdelay_Resp_FollowUp—Link node B sends a Pdelay_Resp_FollowUp message to measure peer-to-peer delay.
○ Announce—Master sends an Announce message to establish a synchronization hierarchy. The BMCA uses the
Announce message to define a clock hierarchy and to select the grandmaster clock.
○ Signaling—Clock A sends a Signaling message to clock B for unicast negotiation and so on.
Time synchronization
Master and slave clock devices exchange PTP timing messages to achieve time synchronization. Slave clock devices adjust their
time to synchronize with their master clock devices.
For time synchronization and to determine the slave offset with the master, PTP accounts for the following:
● Communication delay between two PTP nodes
● End-to-end delay measured using the delay request message from the slave and delay response message from the master
System management
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