Hierarchical Scheduling In Ets Output Policies; Using Ets To Manage Converged Ethernet Traffic; Applying Dcb Policies In A Switch Stack; Configure A Dcbx Operation - Dell S6100 Configuration Manual

• If you configure more than one priority group as strict priority, the higher numbered priority queue is given preference when scheduling
data traffic.

Hierarchical Scheduling in ETS Output Policies

ETS supports up to three levels of hierarchical scheduling.
For example, you can apply ETS output policies with the following configurations:
Priority group 1 Assigns traffic to one priority queue with 20% of the link bandwidth and strict-priority scheduling.
Priority group 2 Assigns traffic to one priority queue with 30% of the link bandwidth.
Priority group 3 Assigns traffic to two priority queues with 50% of the link bandwidth and strict-priority scheduling.
In this example, the configured ETS bandwidth allocation and scheduler behavior is as follows:
Unused bandwidth Normally, if there is no traffic or unused bandwidth for a priority group, the bandwidth allocated to the group is
usage: distributed to the other priority groups according to the bandwidth percentage allocated to each group. However,
when three priority groups with different bandwidth allocations are used on an interface:
•
•
Strict-priority If two priority groups have strict-priority scheduling, traffic assigned from the priority group with the higher
groups: priority-queue number is scheduled first. However, when three priority groups are used and two groups have strict-
priority scheduling (such as groups 1 and 3 in the example), the strict priority group whose traffic is mapped to one
queue takes precedence over the strict priority group whose traffic is mapped to two queues.
Therefore, in this example, scheduling traffic to priority group 1 (mapped to one strict-priority queue) takes precedence over scheduling
traffic to priority group 3 (mapped to two strict-priority queues).

Using ETS to Manage Converged Ethernet Traffic

To use ETS for managing converged Ethernet traffic, use the following command:
dcb-map stack-unit all dcb-map-name

Applying DCB Policies in a Switch Stack

You can apply DCB policies with PFC and ETS configurations to all stacked ports in a switch stack or on a stacked switch.
To apply DCB policies in a switch stack, follow this step.
• Apply the specified DCB policy on all ports of the switch stack or a single stacked switch.
CONFIGURATION mode
dcb-map {stack-unit all | stack-ports all} dcb-map-name

Configure a DCBx Operation

DCB devices use data center bridging exchange protocol (DCBx) to exchange configuration information with directly connected peers
using the link layer discovery protocol (LLDP) protocol.
DCBx can detect the misconfiguration of a peer DCB device, and optionally, configure peer DCB devices with DCB feature settings to
ensure consistent operation in a data center network.
266 Data Center Bridging (DCB)
If priority group 3 has free bandwidth, it is distributed as follows: 20% of the free bandwidth to priority group 1
and 30% of the free bandwidth to priority group 2.
If priority group 1 or 2 has free bandwidth, (20 + 30)% of the free bandwidth is distributed to priority group 3.
Priority groups 1 and 2 retain whatever free bandwidth remains up to the (20+ 30)%.