Reference Guide

• When allocating bandwidth or configuring a queue scheduler for dot1p priorities in a priority group on a DCBx
CIN interface, take into account the CIN bandwidth allocation (refer to Configuring Bandwidth Allocation for
DCBx CIN) and dot1p-queue mapping (QoS dot1p Traffic Classification and Queue Assignment).
• Although an ETS output policy does not support WRED, ECN, rate shaping, and rate limiting because DCBx does
not negotiate these parameters with peer devices, you can apply a QoS output policy with WRED and/or rate
shaping on a DCBx CIN-enabled interface (refer to Configuring Port-Based Rate Shaping and Weighted Random
Early Detection). In this case, the WRED or rate shaping configuration in the QoS output policy takes into
account the bandwidth allocation or queue scheduler configured in the ETS output policy.
• You can only use a QoS ETS output policy in association with a priority group in a DCB output policy and cannot
be applied to an interface as a normal QoS output policy (refer to Applying an ETS Output Policy for a Priority
Group to an Interface and Creating an Output QoS Policy in the Quality of Service (QoS) chapter.).
NOTE: The IEEE 802.1Qaz, CEE, and CIN versions of ETS are supported.
Creating a QoS ETS 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.
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 ETS Output Policy Configuration mode.
POLICY-MAP-OUT-ETS mode
exit
FTOS Behavior: Traffic in priority groups is assigned to strict-queue or WERR scheduling in an ETS output policy and is
managed using the ETS bandwidth-assignment algorithm. FTOS dequeues 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.
FTOS supports hierarchical scheduling on an interface. FTOS control traffic is redirected to control queues as higher
priority traffic with strict-priority scheduling. After control queues drain out, the remaining data traffic is scheduled to
queues according to the bandwidth and scheduler configuration in the ETS output policy. The available bandwidth (that
the ETS algorithm calculates) is equal to the link bandwidth after scheduling non-ETS higher-priority traffic.
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