Cisco 350 Series Administration Manual page 641

Quality of Service
General
STEP 1
STEP 2
STEP 3
STEP 4
Cisco 350, 350X and 550X Series Managed Switches, Firmware Release 2.4, ver 0.4
Queue 1 has the lowest priority, queue 8 in the 350 and 550 families have the highest priority.
To map CoS values to egress queues:
Click Quality of Service > General > CoS/802.1p to Queue.
Enter the parameters.
• 802.1p—Displays the 802.1p priority tag values to be assigned to an egress queue,
where 0 is the lowest and 7 is the highest priority.
• Output Queue—Select the egress queue to which the 802.1p priority is mapped. Either
four or eight egress queues are supported, where Queue 4 or Queue 8 is the highest
priority egress queue and Queue 1 is the lowest priority.
For each 802.1p priority, select the Output Queue to which it is mapped.
Click Apply, Cancel or Restore Defaults. 801.1p priority values to queues are mapped, and
the Running Configuration file is updated, the changes that entered are canceled, or
previously defined values are restored.
DSCP to Queue
The DSCP (IP Differentiated Services Code Point) to Queue page maps DSCP values 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 device is in QoS Basic mode and DSCP is the trusted mode, or
• The device 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.
23
421