user manual

3.2.8. Quality of Service (QoS) Configuration
The switch offers powerful QoS functions including: VLAN tagged priority for 8 levels, TOS
field IP header (equal DSCP low 3 bits) on Layer 3 network framework, 7 types of layer 4
network transmission events, and IP DiffServe QoS services.
In the Quality of Service (QoS) Configuration management interface there is an option
named ”Default Class”. Once you have selected one of the four QoS methods, this Default
Class is used to group packets that do not match any of the QoS rules defined for the
particular QoS method selected. For instance, if you set:
Fi
g
. 3.12
The QoS function as VLAN Tag Priority mode, and then choose Default Class as High, the
priority of the packets with no tags will be considered as High priority precedence. The initial
value of the Default Class is 'High'. This means that’s all packets that don’t have VLAN tags
will be considered as normal packets and be given a high priority. If we set the default class
to Low, then all untagged packets will be considered as low priority and all packets that have
tags will be considered as High Priority.
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