Dell PowerSwitch S4820T 9.50.1 Configuration Guide for the S4820T System - Page 276
Creating a QoS DCB Output Policy, Exit DCB Output Policy Configuration mode.
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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 StrictPriority 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 strictpriority 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 276 Data Center Bridging (DCB)
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