Spectracom NetClock 9400 Series, User Reference Manual

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Min Announce Interval : The minimum value of the Announce interval granted by the
Master Clock. In packets per second. [128 Per Second
Max Announce Duration : The maximum value of the Announce interval granted by the
Master Clock. In seconds. [10000]
Min Delay_Req Interval : In packets per second. [128 Per Second]
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 T r a n s m i s s i o n M o d e s
The PTP Card is able to transmit the PTP packets in three transmission modes:
• Multicast Mode
: This is the default mode. PTP packets are transmitted to all PTP Clocks by means
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
: This is a Point-to-Point transmission mode between two PTP Clocks by means of
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
and
Follow-Up
,
Delay_Req
and
Delay_Resp
.
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
: The Minicast/Hybrid mode is a method to minimize the PTP packets
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.
NetClock User Reference Guide 369
APPENDIX