Users Guide

1146 Data Center Bridging Features
4 0 Weighted Tail Drop
5 0 Weighted Tail Drop
6 0 Weighted Tail Drop
5. Map the CoS Queues to TCGs
In this step, CoS queues are mapped to Traffic Class Groups (TCGs). Since
TCGs are serviced from highest numbered TCG to lowest, higher priority
traffic should be assigned to higher numbered TCGs. In general, strict
priority traffic (typically control plane or low bandwidth, low latency traffic) is
assigned the highest numbered TCG. It is recommended that WDRR queues
be assigned to TCG0.
The mapping may be configured on a single interface, a range of interfaces, or
all the interfaces.
It is required that TCGs always be assigned in order from 0 to 2. It is further
recommended that the operator always utilize consecutive TCGs starting
with TCG 0; for example, use TCG 0 and 1 vs. TCG 0 and 2 only.
This example assigns best effort traffic to TCG 0, lossless traffic to TCG 1,
and expedited service traffic to TCG 2.
console(config-if-Te1/0/1)#classofservice traffic-class-group 0 0
console(config-if-Te1/0/1)#classofservice traffic-class-group 1 1
console(config-if-Te1/0/1)#classofservice traffic-class-group 2 1
console(config-if-Te1/0/1)#classofservice traffic-class-group 3 2
To show the CoS queue to TCG mapping, use the following command:
console#show classofservice traffic-class-group tengigabitethernet
1/0/1
Traffic Class Traffic Class Group
------------- ------------------
0 0
1 1
2 1
3 2
4 0
5 0
6 0
6. Set the Weight for Each TCG
This step configures the scheduling weight for each TCG. The weight
percentage configures the scheduler to ensure that each TCG is nominally
serviced in the ratio specified.