Deployment Guide

If you configure more than one priority queue as strict priority or more than one priority group as strict priority, the higher
numbered priority queue is given preference when scheduling data traffic.
If multiple lossful priorities are mapped to a single priority group (PG1) and lossless priorities to another priority group (PG0),
then bandwidth split across lossful priorities is not even.
ETS Operation with DCBx
The following section describes DCBx negotiation with peer ETS devices.
In DCBx negotiation with peer ETS devices, ETS configuration is handled as follows:
●
ETS TLVs are supported in DCBx versions CIN, CEE, and IEEE2.5.
● The DCBx port-role configurations determine the ETS operational parameters (refer to Configure a DCBx Operation).
● ETS configurations received from TLVs from a peer are validated.
● If there is a hardware limitation or TLV error:
○ DCBx operation on an ETS port goes down.
○ New ETS configurations are ignored and existing ETS configurations are reset to the default ETS settings.
● ETS operates with legacy DCBx versions as follows:
○ In the CEE version, the priority group/traffic class group (TCG) ID 15 represents a non-ETS priority group. Any priority
group configured with a scheduler type is treated as a strict-priority group and is given the priority-group (TCG) ID 15.
○ The CIN version supports two types of strict-priority scheduling:
￭ Group strict priority: Use this to increase its bandwidth usage to the bandwidth total of the priority group and allow a
single priority flow in a priority group. A single flow in a group can use all the bandwidth allocated to the group.
￭ Link strict priority: Use this to increase to the maximum link bandwidth and allow a flow in any priority group.
NOTE:
CIN supports only the dot1p priority-queue assignment in a priority group. To configure a dot1p priority flow
in a priority group to operate with link strict priority, you configure: The dot1p priority for strict-priority scheduling
(strict-priority command). The priority group for strict-priority scheduling (scheduler strict command.
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/subport
Data Center Bridging (DCB)
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