Spectracom SecureSync User Reference Manual page 431

The Master Clock selected by the BMC algorithm as the Best Master Clock will transition into the
Master state to become the active Master Clock on the network. It will then start to transmit Sync
packets to the Slave Clocks. The other Master Clocks will transition into the Passive state.
Configuring Unicast Mode
For information on Unicast mode, see "Transmission Modes" on the next page.
The unicast mode is activated at the initiative of the Slaves. Each Slave, which wants to run in uni-
cast mode, shall first negotiate unicast contracts with the Master.
To enter the Unicast mode, perform the following steps:
On the Master side:
On the Slave side:
When the Master Clock is set in multicast mode, this one will deny the requests from the Slaves
Clocks to run in Unicast mode.
When the Master Clock is set in Unicast mode, it does not transmit any PTP messages until a
Slave has been granted to run in Unicast mode.
Configuring Master/Slave Mode
The PTP Master/Slave option card [- 12] also supports a combined Master/Slave mode. The
Master/Slave mode works best in a SecureSync which is not synchronized to any other reference.
When the module is plugged into the PTP network, it will become a slave to the Best Master Clock
on the network.
If all Master Clocks are removed from the network, the SecureSync containing the Master/Slave
module will go into Holdover mode. However, the module will use that Holdover time to become
CHAPTER •
5 SecureSync User Reference Guide Rev. 18
i.
The BMC algorithm first selects the clock having the higher Priority1 parameter (a
lowest value means a higher priority)
ii.
If the BMC cannot be determined from the previous parameter, the BMC algorithm
selects the clock having the higher Clock Quality (Clock Class, Clock Accuracy,
Clock Variance)
iii.
If the BMC cannot be determined from the previous parameters, the BMC algorithm
selects the clock having the higher Priority2 parameter
In the PTP Edit window under the Main tab, select Multicast for the Transmission Mode .
Enable the Unicast mode.
In the PTP Edit window under the Main tab, select Multicast for the Transmission Mode .
Enable the Unicast mode.
NOTE – The Unicast mode is only implemented for the following PTP packets:
- Announce
- Sync and Follow-Up
- Delay_Req and Delay_Resp
5.5 Network Interface Option Cards
415