Hol Blocking Prevention; Scheduling Settings; Qos Scheduling - D-Link xStack Reference Manual

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xStack DGS-3620 Series Layer 3 Managed Stackable Gigabit Switch Web UI Reference Guide
DSCP List (0-63)
Priority
DSCP (0-63)
Port
Click the Apply button to accept the changes made.
Click the Find button to locate a specific entry based on the information entered.

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 shown below:
The fields that can be configured are described below:
Parameter
HOL Blocking
Prevention State
Click the Apply button to accept the changes made.

Scheduling Settings

QoS Scheduling

This window allows the user to configure the way the Switch will map an incoming packet per port based on its
802.1p user priority, to one of the eight available hardware priority queues available on the Switch.
To view this window, click QoS > Scheduling Settings > QoS Scheduling as shown below:
DSCP Priority – Specify a list of DSCP values to be mapped to a specific priority.
DSCP DSCP – Specify 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 DSCP in the DSCP Map
drop-down menu.
Use the drop-down menu to select a port.
Figure 7-10. HOL blocking Prevention window
Description
Click the radio buttons to enable of disable the HOL blocking prevention global
settings.
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