Reference Guide

730 | Quality of Service (QoS)
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Mapping dot1p values to service queues:
Mapping dot1p values to service queues is available on the S5000 switch.
On the S5000 all traffic is by default mapped to the same queue, Queue 0. If you honor dot1p on ingress,
then you can create service classes based a queueing strategy that uses the command
service-class dynamic
dot1p
from INTERFACE mode. You may apply this queuing strategy globally by entering this command
from CONFIGURATION mode.
• All dot1p traffic is mapped to Queue 0 unless
service-class dynamic dot1p is enabled on an interface or
globally.
• Layer 2 or Layer 3 service policies supersede dot1p service classes.
Guaranteeing bandwidth to dot1p-based service queues:
Guarantee a minimum bandwidth to queues globally from CONFIGURATION mode with the command
service-class bandwidth-weight. The command is applied in the same way as the bandwidth-weight command
in an output QoS policy (see Allocating bandwidth to queue on page 727). The
bandwidth-weight command
in QOS-POLICY-OUT mode supersedes the
service-class bandwidth-weight command.
Applying an input policy map to an interface
Apply an input policy map to an interface using the command service-policy input from INTERFACE mode.
Specify the keyword
layer2 if the policy map you are applying a Layer 2 policy map; in this case, the
INTERFACE must be in switchport mode. You can apply the same policy map to multiple interfaces, and
you can modify a policy map after you apply it.
• You cannot apply a class-map and QoS policies to the same interface.
• You cannot apply an input Layer 2 QoS policy on an interface you also configure with
vlan-stack
access
.
• If you apply a service policy that contains an ACL to more than one interface, Dell Networking OS
uses ACL optimization to conserves CAM space. The ACL Optimization behavior detects when an
ACL already exists in the CAM and rather than writing it to the CAM multiple times.
Creating Output Policy Maps
Creating Output Policy Maps is supported only on the S5000 switch.
1. Create an output policy map using the command
policy-map-output from CONFIGURATION mode.
2. Once you create an output policy map, do one or more of the following:
• Applying an output QoS policy to a queue
• Specifying an aggregate QoS policy
• Applying an output policy map to an interface
3. Apply the policy map to an interface. See page 61.
Applying an output QoS policy to a queue: