Hol Blocking Prevention - D-Link DGS-3120-24TC Product Manual

xStack® DGS-3120 Series Managed Switch Web UI Reference Guide
The fields that can be configured are described below:
Parameter
Unit
From Port / To Port
DSCP Map
DSCP List
Priority
DSCP
Click the Apply button to accept the changes made.

HOL Blocking Prevention

HOL (Head of Line) Blocking happens when one of the destination ports of a broadcast or multicast packet are
busy. The switch will hold this packet in the buffer while the other destination port will not transmit the packet even
they are not busy.
The HOL Blocking Prevention will ignore the busy port and forward the packet directly to have lower latency and
better performance.
On this page the user can enable or disable HOL Blocking Prevention.
To view the following window, click QoS > HOL Blocking Prevention, as show below:
The fields that can be configured are described below:
Parameter
Figure 6–9 DSCP Map Settings - DSCP DSCP window
Description
Select the unit you want to configure.
Use the drop-down menu to select a range of port to configure.
Use the drop-down menu to select one of two options:
DSCP Priority – Specifies a list of DSCP values to be mapped to a specific priority.
DSCP DSCP – Specifies a list of DSCP value to be mapped to a specific DSCP.
Enter a DSCP List value.
Use the drop-down menu to select a Priority value. This appears when selecting
DSCP Priority in the DSCP Map drop-down menu.
Enter a DSCP value. This appears when selecting DSCP Priority in the DSCP
DSCP drop-down menu.
Figure 6–10 HOL blocking Prevention window
Description
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