Spectracom SecureSync 1200 User Reference Manual page 477

Max Delay_Req Duration : In seconds. [10000]
Max Slaves : The maximum number of slaves the card will serve. [4000]
Advanced tab settings
A b o u t ... P T P
The PTP Card is able to transmit the PTP packets in three transmission modes:
• Multicast Mode
of Multicast IP addresses dedicated to the PTP protocol (224.0.1.129, 224.0.0.107). PTP packets
received by the PTP Clocks are then filtered from the Domain Number, the Port Identity (Clock Identity
+ Port Number) of the transmitter, the packet identifier (Sequenced). When the Master Clock is set in
Multicast mode, this module will deny the requests from the Slaves Clocks to run in Unicast mode.
When the Master Clock is set in Unicast mode, it doesn't transmit any PTP messages until a Slave has
been granted to run in Unicast mode.
• Unicast Mode
the unique IP address assigned to each PTP Clock.
---------------------------------------------
N O T E: The Unicast mode is only implemented for the following PTP packets:
Announce Sync
,
The Unicast mode is activated at the initiative of the Slaves. Each Slave, which wants to run in Unicast
mode, shall first negotiate Unicast contracts with the Master.
_______________
• Minicast/Hybrid Mode
payload on the network, where: The transmissions initiated by the Master (Announce, Sync/Follow-
Up) run in Multicast mode.
The transmissions initiated by the Slaves (Delay_Req/Delay_Resp) run in Unicast mode.
Multicast Sync : Activating this option will cause the PTP Master to broadcast Sync and
Announce messages to the Multicast address (as long as it is the Best Master on the net
work). Deactivating this option will remove the messages. When the PTP module is set in
multicast mode, this will deny the requests from the Slaves Clocks to running in unicast
mode.
SecureSync User Reference Guide
T r a n s m i s s i o n M o d e s
: This is the default mode. PTP packets are transmitted to all PTP Clocks by means
: This is a Point-to-Point transmission mode between two PTP Clocks by means of
Follow-Up Delay_Req
and ,
: The Minicast/Hybrid mode is a method to minimize the PTP packets
Delay_Resp
and .
APPENDIX
461