Owners Manual

Creating a QoS DCB Output Policy
A QoS output policy that you create to optimize bandwidth on an output interface for specified priority
traffic consists of the ETS settings (the bandwidth percentage and queue schedule) used in DCBx
negotiations with peer devices.
1. Create a QoS output policy to configure the ETS bandwidth allocation and scheduling for priority
traffic.
CONFIGURATION mode
qos-policy-output policy-name ets
The maximum is 32 characters.
2. (Optional) Configure the method used to schedule priority traffic in port queues.
POLICY-MAP-OUT-ETS mode
scheduler value
strict — Strict priority traffic is serviced before any other queued traffic (refer to Enabling Strict-
Priority Queueing in the Quality of Service (QoS) chapter).
NOTE: If you configure a scheduling method, you cannot configure bandwidth allocation in
Step 3.
werr —Weighted elastic round robin provides low-latency scheduling for priority traffic on port
queues. WERR scheduling is used to queue priority traffic by default.
3. (Optional) Configure the bandwidth percentage allocated to priority traffic in port queues.
POLICY-MAP-OUT-ETS mode
bandwidth-percentage percentage
The percentage range is from 1 to 100% in units of 1%. The sum of bandwidth percentage assigned to
dot1p priorities/queues in a priority group should be 100%.
The default is none.
NOTE: If you configure bandwidth allocation, you cannot configure a scheduling method in
Step 2.
4. Exit DCB Output Policy Configuration mode.
POLICY-MAP-OUT-ETS mode
exit
Dell Networking OS Behavior: Traffic in priority groups is assigned to strict-queue or WERR scheduling in
an DCB output policy and is managed using the ETS bandwidth-assignment algorithm. Dell Networking
OS deqeues all frames of strict-priority traffic before servicing any other queues. A queue with strict-
priority traffic can starve other queues in the same port.
ETS-assigned bandwidth allocation and scheduling apply only to data queues, not to control queues.
Dell Networking OS supports hierarchical scheduling on an interface. Dell Networking OS control traffic
is redirected to control queues as higher priority traffic with strict-priority scheduling. After control
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Data Center Bridging (DCB)