Configuring Quality of Service
Configuring QoS
Cisco Small Business 300 Series Managed Switch Administration Guide  254
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• Restore Defaults—Click to restore all queues to the factory default CoS/
802.1pto Queue mapping.
STEP  3 For each 802.1p priority select the Output Queue to which it is mapped. 
STEP  4 Click Apply. 801.1p priority values to queues are mapped, and the switch is 
updated.
Mapping DSCP to Queue
The DSCP (IP Differentiated Services Code Point) to Queue Page maps DSCP to 
egress queues. The DSCP to Queue Table determines the egress queues of the 
incoming IP packets based on their DSCP values. The original VPT (VLAN Priority 
Tag) of the packet is unchanged.
By simply changing the DSCP to Queue mapping and the Queue schedule method 
and bandwidth allocation, it is possible to achieve the desired quality of services 
in a network.
The DSCP to Queue mapping is applicable to IP packets if:
• The switch is in QoS Basic mode and DSCP trusted mode, or
• The switch is in QoS Advanced mode and the packets belongs to flows that 
is DSCP trusted
Non-IP packets are always classified to the best-effort queue
To  m a p  D S C P  t o  q u e u e s :
STEP 1 Click Quality of Service > General > DSCP to Queue. The DSCP to Queue Page 
opens.
The DSCP to Queue Page contains Ingress DSCP. It displays the DSCP value in 
the incoming packet and its associated class. 
STEP  2 Select the Output Queue (traffic forwarding queue) to which the DSCP value is 
mapped. 
STEP  3 Click Apply. The switch is updated.