Dell N2000 Series, Configuration Manual

Page: 1007 / 1460

Configuring Data Center Bridging Features
1007
It is recommended that the sum of minimum bandwidth percentages
configured on the CoS queues mapped to any TCG be less than or equal to
that of the weight percentage configured for the TCG, so that packets are not
dropped due to the congestion in the TCG.
In example below, the TCG0 and TCG1 are allocated 30% and 70% of the
bandwidth remaining after servicing TCG2 (strict priority) traffic. TCG2
traffic is handled with strict priority but can only consume up to 100% minus
the sum of the minimum bandwidths of TCG0 and TCG1 (60%).
console(config-if-Te1/0/1)#traffic-class-group weight 30 70 0
7. Set the Minimum Bandwidth for Each TCG (optional)
In this step, the minimum bandwidth is configured for each TCG while in
congestion. The minimum bandwidth setting ensures that a TCG is serviced
during congestion even if a higher priority TCG has an offered load greater
than 100% minus the minimum bandwidth assigned to the other TCGs.
The minimum bandwidth is enforced on the egress TCG regardless of the
scheduling mode and does not directly affect incoming traffic. The minimum
bandwidth for a TCG is configured as a percentage of the total bandwidth,
and the configured minimum bandwidths may sum to less than 100%. The
sum may not exceed 100%. Minimum bandwidth may be configured on a
single interface, a range of interfaces, or all interfaces. It is recommended that
the minimum bandwidth for a TCG be configured to be less than or equal to
the weight of the TCG.
CAUTION:
Sharing of bandwidth among TCGs is disabled if the sum of the
minumum bandwidth settings equals 100%.
console(config-if-Te1/0/1)#traffic-class-group min-bandwidth 10 50 0
8. Set the Maximum Bandwidth for each TCG (optional)
In this step, the maximum bandwidth for each TCG is configured. The
bandwidth allowed for the TCG will never exceed the maximum bandwidth
configured, even if configured for strict priority. This limit is configured as a
percentage of the total bandwidth and is used to shape egress traffic bursts to
no greater than the configured value. The maximum bandwidth may be
configured on a single interface, range of interfaces or all interfaces. When
configured to be 0, unlimited bandwidth is allowed on the TCG.