Users Guide

The following is the sequence of PTP messages during time synchronization:
1. Master sends a Sync message and makes note of the time t1 when the message was sent.
2. Slave receives the Sync message and makes note of the time t2 when the message was sent.
3. Master embeds the timestamp t1 in the Sync message.
4. Slave sends a Delay_request message to the master and makes note of the time t3 when the message was sent.
5. Master receives the Delay_request message and makes note of the time t4 when the message was sent.
6. Master conveys the timestamp t4 in a Delay_response message.
7. Slave uses these timestamps to adjust its local clock to synchronize with the master:
● Offset = [(t2 – t1) – (t4 – t3)] / 2
● Delay = [(t2 – t1) + (t4 – t3)] / 2
Supported profiles
OS10 supports the following PTP profiles:
● System default profile
● G.8275.1 profile
Supported transport methods
OS10 supports the following PTP transport methods:
● Layer2 (Ethernet)
● IPv4 (Unicast and multicast)
● IPv6 (Unicast and multicast)
For the multicast transport method, as defined in the IEEE 1588 standard, PTP uses 224.0.1.129 as the multicast destination
IPv4 address. PTP uses FF0X:0:0:0:0:0:0:181 as the multicast destination IPv6 address.
NOTE: OS10 supports IPv6 multicast only between two directly-connected IPv6 PTP nodes.
Configurable PTP attributes
The following are configurable PTP attributes that BMCA uses to determine the master and slave clock devices:
216
System management