Lantronix
SM12XPA Web User Guide
33848 Rev. A
Page
296
of
473
Frame Preemption Configuration
This page provides an overview of TSN Egress Port Frame Preemption configuration.
Frame preemption defines two MAC services for an egress port: preemptable MAC (pMAC) and express MAC
(eMAC). Express frames can interrupt transmission of preemptable frames. On resume, the MAC merge sublayer
re-assembles frame fragments in the next bridge.
Figure 18-1.2: Frame Preemption Configuration
Parameter descriptions
:
Port
: The logical port for the settings contained in the same row.
Note
that Frame Preemption is not supported
on ports with maximum speed 25 Gigabit/second and is also not supported on 10G Gigabit/sec Aquantia Copper
ports.
Frame Preemption TX
: The value of the 802.3br
aMACMergeEnableTx
parameter for the port. This value
determines whether frame preemption is enabled (checked) or disabled (unchecked) in the MAC Merge
sublayer in the transmit direction. The default is checkbox unchecked.
Start without LLDP
: When this field is checked, Frame Preemption will be active when Frame Preemption TX is
checked. The default is FALSE (checkbox unchecked).
Verify Disable TX
: The value of the 802.3br
aMACMergeVerifyDisableTx
parameter for the port. This value
determines whether the verify function is enabled (checked) or disabled (unchecked) in the MAC Merge
sublayer in the transmit direction. The default is FALSE (checkbox unchecked).
Preemptable Queues TX
: This parameter is the administrative value of the preemption status for the priority.
If checked, it takes value preemptable if frames queued for the priority are to be transmitted using the
preemptable service for the Port. If not checked, it takes value express if frames queued for the priority are to
be transmitted using the express service for the Port and preemption is enabled for the Port.