D-Link DXS-3600 Series Reference Manual page 330

DXS-3600 Series Layer 3 Managed 10Gigabit Ethernet Switch Web UI Reference Guide
The fields that can be configured are described below:
Parameter
Unit
From Port ~ To Port
Scheduler Method
Figure 7-2 Port Scheduler Method Window
Description
Select the switch unit that will be used for this configuration here.
Select the range of ports that will be used for this configuration here.
Select the scheduler method that will be applied to the specified
port(s). Options to choose from are Strict Priority (SP), Round-Robin
(RR), Weighted Round-Robin (WRR), Weighted Deficit Round-Robin
(WDRR), and Enhanced Transmission Selection (ETS). By default, the
output queue scheduling algorithm is WRR.
•
Strict Priority (SP) specifies that all queues use strict priority
scheduling. It provides strict priority access to the queues from
the highest CoS queue to the lowest.
•
Round-Robin (RR) specifies that all queues use round-robin
scheduling. It provides fair access to service a single packet at
each queue before moving on to the next one.
•
Weighted Round-Robin (WRR) operates by transmitting
permitted packets into the transmit queue in a round robin order.
Initially, each queue sets its weight to a configurable weighting.
Every time a packet from a higher priority CoS queue is sent, the
corresponding weight is subtracted by 1 and the packet in the
next lower CoS queue will be serviced. When the weight of a
CoS queue reaches zero, the queue will not be serviced until its
weight is replenished. When weights of all CoS queues reach 0,
the weights get replenished at a time.
•
Weighted Deficit Round-Robin (WDRR) operates by serving
an accumulated set of backlogged credits in the transmit queue
in a round robin order. Initially, each queue sets its credit counter
to a configurable quantum value. Every time a packet from a
CoS queue is sent, the size of the packet is subtracted from the
corresponding credit counter and the service right is turned over
to the next lower CoS queue. When the credit counter drops
below 0, the queue is no longer serviced until its credits are
replenished. When the credit counters of all CoS queues reaches
0, the credit counters will be replenished at that time. All packets
are serviced until their credit counter is zero or negative and the
last packet is transmitted completely. When this condition
happens, the credits are replenished. When the credits are
replenished, a quantum of credits are added to each CoS queue
credit counter. The quantum for each CoS queue may be
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