Wred; Wred Profile - D-Link DGS-3630 Series Reference Manual

DGS-3630 Series Layer 3 Stackable Managed Switch Web UI Reference Guide
Parameter
Unit
From Port - To Port
Frame Type
Click the Clear button to clear the counters based on the selections made.

WRED

Weighted Random Early Detection (WRED) is another implementation for QoS that will help the overall throughput for
your QoS queues. Based on the egress queue of the QoS function set on the Switch, this method will analyze these
packets and their QoS queue to determine if there will be an overflow of packets entering the QoS queues and
consequentially, minimize the packet flow into these queues by dropping random packets. WRED employs two
methods of avoiding congestion within the QoS queue.
1. Every QoS queue has a minimum and a maximum level for acceptance of packets. Once the maximum
threshold has been reached for this queue, the Switch will begin discarding all ingress packets, this minimizing
the allotted bandwidth for QoS. When below the minimum threshold, the Switch will accept all ingress packets.
2. When the ingress packets are somewhere between the maximum and minimum queue, the Switch will use a
slope probability function to determine a random method of dropping packets based on the maximum drop rate
which specifies the drop probability when the queues reach maximum threshold. If queues are closer to the
maximum threshold, the Switch will increase the discarding of random packets to even out the flow to the
queues and avoid overflows to higher priority queues.

WRED Profile

This window is used to display and configure the Weighted Random Early Detection (WRED) profile settings.
To view the following window, click QoS > WRED > WRED Profile, as shown below:
Description
Select the Switch unit ID that will be used here.
Select the Switch port range that will be used here. Select the All option to specify
that all ports will be used here.
Select the frame type that will be cleared here. Options to choose from are:
• RX - Specifies to clear the counters of received PFC frames.
• TX - Specifies to clear the counters of transmitted PFC frames.
• Both - Specifies to clear the counters of received and transmitted PFC
frames.
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