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EdgeSync Manual rev 1 | 53
The slave acceptance filter is a mechanism to control which slave nodes may obtain unicast services
from the master. If the filter table is empty no services will be granted to any node. The PTP :: Unicast
Section of this User Guide is used to manipulate the slave acceptance filter.
As the result of the filter table modification, if a node becomes unacceptable or message rates of any
active grants becomes beyond the newly configured limits, all affected grants will be cancelled.
Maintaining Master’s List of Static Slaves
Note: In the current implementation, this is not supported.
To provide unicast services to slaves
which do not support the unicast negotiation the master maintains a list of static slave nodes.
When a node is in this list the master can send Announce and Sync messages to that node and can
reply to Delay Request messages received from that node.
PTP :: Unicast Section of this User Guide is used to monitor and manipulate the static slave node list.
Unicast BOTH mode of operation
The PTP port on EdgeSync can be configured to automatically assume either the role of a unicast
Master or a unicast Slave when the port mode is unicast BOTH. For example, if a port is in unicast
Master mode and has GNSS reference and if the GNSS reference is lost, it can switch over to unicast
Slave to another GM in the network. It is important to note that it is mutually exclusive, and cannot
assume both, unicast Master and unicast Slave role at the same time as the case would be in a single-
armed boundary clock.
Unicast MIXED mode of operation
The MIXED mode of operation is also referred to as PTP hybrid mode. In this mode, the Announce and
Sync messages are sent as a multicast, but the delay mechanism is in unicast mode. The advantage of
doing so is two-fold in a network of single master and many slaves that are being serviced by that
Master:
•
The Master does not have to replicate the Announce and Sync (and Follow-up) messages for
each slave in its time domain or in the network,
•
Each slave does not have to receive, process and drop DelayReq and DelayResponse messages
from other slaves in the network.
PTP Master
PTP Slave A
PTP Slave B
SYNC
Ann
Delay
Resp
Delay
Resp
Delay
Req B
Delay
Req A
Multicast
Unicast
Unicast
Unicast
