Administrator Guide

Configuring Bandwidth Allocation for DCBx CIN
After you apply an ETS output policy to an interface, if the DCBx version used in your data center network is CIN, you may need to
configure a QoS output policy to overwrite the default CIN bandwidth allocation.
This default setting divides the bandwidth allocated to each port queue equally between the dot1p priority traffic assigned to the queue.
To create a QoS output policy that allocates different amounts of bandwidth to the different traffic types/ dot1p priorities assigned to a
queue and apply the output policy to the interface, follow these steps.
1. Create a QoS output policy.
CONFIGURATION mode
Dell(conf)#qos-policy-output test12
The maximum 32 alphanumeric characters.
2. Configure the percentage of bandwidth to allocate to the dot1p priority/queue traffic in the associated L2 class map.
QoS OUTPUT POLICY mode
Dell(conf-qos-policy-out)#bandwidth-percentage 100
The default is none.
3. Repeat Step 2 to configure bandwidth percentages for other priority queues on the port.
QoS OUTPUT POLICY mode
Dell(conf-qos-policy-out)#bandwidth-percentage 100
4. Exit QoS Output Policy Configuration mode.
QoS OUTPUT POLICY mode
Dell(conf-if-te-0/1)#exit
5. Enter INTERFACE Configuration mode.
CONFIGURATION mode
interface type slot/port
6. Apply the QoS output policy with the bandwidth percentage for specified priority queues to an egress interface.
INTERFACE mode
Dell(conf-if-te-0/1)#service-policy output test12
Configuring ETS in a DCB Map
A switch supports the use of a DCB map in which you configure enhanced transmission selection (ETS) setting. To configure ETS
parameters, you must apply a DCB map on an interface.
ETS Configuration Notes
ETS provides a way to optimize bandwidth allocation to outbound 802.1p classes of converged Ethernet traffic. Different traffic types
have different service needs. Using ETS, you can create groups within an 802.1p priority class to configure different treatment for traffics
with different bandwidth, latency, and best-effort needs.
When you configure ETS in a DCB map:
• The DCB map associates a priority group with a PFC operational mode (on or off) and an ETS scheduling and bandwidth allocation.
You can apply a DCB map on multiple egress ports.
• Use the ETS configuration associated with 802.1p priority traffic in a DCB map in DCBx negotiation with ETS peers.
• Traffic in priority groups is assigned to strict-queue or weighted round-robin (WRR) scheduling in an ETS configuration and is
managed using the ETS bandwidth-assignment algorithm. Dell EMC Networking OS de-queues 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 strict-priority scheduling apply only to data queues, not to control queues.
• Dell EMC Networking OS supports hierarchical scheduling on an interface. The control traffic on Dell EMC Networking OS is
redirected to control queues as higher priority traffic with strict priority scheduling. After the control queues drain out, the remaining
data traffic is scheduled to queues according to the bandwidth and scheduler configuration in the DCB map. The available bandwidth
calculated by the ETS algorithm is equal to the link bandwidth after scheduling non-ETS higher-priority traffic.
• The configuration of bandwidth allocation and strict-queue scheduling is not supported at the same time for a priority group.
• Bandwidth assignment: By default, equal bandwidth is assigned to each dot1p priority in a priority group. To configure the bandwidth
assigned to the port queues associated with dot1p priorities in a priority group, use the bandwidth percentage parameter. The sum of
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Data Center Bridging (DCB)