Table Of Contents

wrr-queue cos-map

wrr-queue queue-limit

wrr-queue random-detect

wrr-queue threshold

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wrr-queue cos-map

To map CoS values to drop thresholds for a queue, use the wrr-queue cos-map command. Use the no form of this command to return to the default settings.

wrr-queue cos-map queue-id threshold-id cos-1 ... cos-n

no wrr-queue cos-map

Syntax Description

queue-id	Queue number; the valid value is 1.
threshold-id	Threshold ID; valid values are from 1 to 4.
cos-1 ... cos-n	CoS value; valid values are from 0 to 7.

Defaults

The defaults are as follows:

•Receive queue 1/drop threshold 1 and transmit queue 1/drop threshold 1: CoS 0 and 1.

•Receive queue 1/drop threshold 2 and transmit queue 1/drop threshold 2: CoS 2 and 3.

•Receive queue 2/drop threshold 3 and transmit queue 2/drop threshold 1: CoS 4 and 6.

•Receive queue 2/drop threshold 4 and transmit queue 2/drop threshold 2: CoS 7.

•On 1p1q4t, 1p2q2t, and 1p3q1t interfaces, CoS 5 is mapped to the strict-priority queues.

Command Modes

Interface configuration

Command History

Release	Modification
12.0(7)XE	Support for this command was introduced on the Catalyst 6500 series switches.
12.1(1)E	Support for this command on the Catalyst 6500 series switches was extended to the 12.1 E release.
12.1(5c)EX	This command was changed to support the 1p1q0t and 1p3q1t interfaces.

Usage Guidelines

Enter up to eight CoS values to map to the threshold.

The threshold for 1p3q1t is always 1.

Examples

This example shows how to map the CoS values 0 and 1 to standard transmit queue 1/threshold 1:

Router(config-if)# wrr-queue cos-map 1 1 0 1 

Router(config-if)#

wrr-queue queue-limit

To set the transmit queue size ratio on an interface, use the wrr-queue queue-limit command. Use the no form of this command to return to the default settings.

wrr-queue queue-limit {queue1-weight [queue2-weight] queue3-weight}

no wrr-queue queue-limit

Syntax Description

queue1-weight	Ratio of the low-priority queue weight; valid values are from 1 and 100 percent.
queue2-weight	(Optional) Ratio of the medium-priority queue weight; valid values are from 1 and 100 percent.
queue3-weight	Ratio of the high-priority queue weight; see the "Usage Guidelines" section for valid values.

Defaults

The defaults are as follows:

•90 percent for low priority

•10 percent for high priority

Command Modes

Interface configuration

Command History

Release	Modification
12.0(7)XE	Support for this command was introduced on the Catalyst 6500 series switches.
12.1(1)E	Support for this command on the Catalyst 6500 series switches was extended to the 12.1 E release.
12.1(5c)EX	This command was changed to support the 1p1q0t and 1p3q1t interfaces.
12.1(8a)EX	The acceptable minimum value of the high-priority queue was changed.

Usage Guidelines

Valid high-priority weight values are from 1 to 100 percent, except on 1p2q1t egress LAN ports, where valid values for the high-priority queue are from 5 to 100 percent.

On 1p2q2t interfaces, QoS sets the strict-priority queue size equal to the high-priority queue size.

Estimate the mix of low priority-to-high priority traffic on your network (for example, 80 percent low-priority traffic and 20 percent high-priority traffic). Use the estimated percentages as queue weights.

Due to the granularity of programming the hardware, the values set in hardware are close approximations of the values provided. For example, even if you specify 0 percent, the actual value programmed depends on the module type and is not necessarily 0. Whatever weights you choose, make sure that the resulting byte values that are programmed (see the show queueing interface command) are at least equal to the MTU size.

Examples

This example shows how to configure the transmit-queue size ratio:

Router (config-if)# wrr-queue queue-limit 75 25

Router(config-if)#

Related Commands

show queueing interface
wrr-queue bandwidth

wrr-queue random-detect

To enable WRED or specify the minimum and maximum WRED threshold for the specified queues on 1p2q2t and 1p3q1t interfaces, use the wrr-queue random-detect command. Use the no form of this command to return to the default settings.

wrr-queue random-detect queue-id

wrr-queue random-detect {max-threshold | min-threshold} queue-id threshold-percent-1 ... threshold-percent-n

no wrr-queue random-detect queue-id

no wrr-queue random-detect {max-threshold | min-threshold} queue-id

Syntax Description

queue-id	Queue number; valid values are 1, 2, or 3.
max-threshold	Specifies the maximum WRED-drop threshold.
min-threshold	Specifies the minimum WRED-drop threshold.
threshold-percent-1 threshold-percent-n	Threshold weights; valid values are from 1 to 100 percent.

Defaults

The default is WRED is disabled. When WRED is enabled, the defaults are as follows:

•The maximum threshold is (low) 40 percent and (high) 100 percent.

•The minimum thresholds are both set to zero.

Command Modes

Interface configuration mode

Command History

Release	Modification
12.1(5c)EX	Support for this command was introduced on the Supervisor Engine 2.
12.1(8a)E	Support for this command on the Supervisor Engine 2 was extended to the 12.1 E release.

Usage Guidelines

1p2q1t and 1p3q1t interfaces have WRED-drop thresholds in their standard transmit queues. You can configure 1p3q1t tranmsit queues to use a WRED-drop threshold or a tail-drop threshold.

To enable WRED-drop thresholds on 1p2p1t interfaces, enter the wrr-queue random-detect queue-id command. Use the no form of this command to disable WRED.

To enable WRED-drop threshold on 1p3q1t interfaces, enter the wrr-queue random-detect queue-id command. To return to the tail-drop threshold, enter the no wrr-queue random-detect queue-id command.

The queue-id is 1 for the standard low-priority queue, 2 is for the standard high-priority queue, and 3 is for strict priority.

The threshold in the strict-priority queue is not configurable.

Each queue on a 1p2q2t interface has two thresholds; 1p3q1t interfaces have one threshold.

Each threshold has a low and a high WRED value.

WRED values are a percentage of the queue capacity.

For additional information on configuring WRED thresholds, refer to the QoS chapter in the Catalyst 6500 Series Switch Cisco IOS Software Configuration Guide.

Examples

This example shows how to configure the low-priority transmit-queue high-WRED drop thresholds:

Router (config-if)# wrr-queue random-detect max-threshold 1 60 100

Router (config-if)# 

Related Commands

show queueing interface
wrr-queue queue-limit

wrr-queue threshold

To configure drop threshold percentages for the standard receive and transmit queues on 1q4t and 2q2t interfaces, use the wrr-queue threshold command. Use the no form of this command to return to the default settings.

wrr-queue threshold queue-id threshold-percent-1 ... threshold-percent-n

no wrr-queue threshold queue-id

Syntax Description

queue-id	Queue number; valid values are 1 and 2.
threshold-percent-1 threshold-percent-n	Number of weights for queues 1 and 2; valid values are from 1 to 100 percent.

Defaults

When you enable QoS, the default settings are as follows:

•100 percent for threshold 1

•60 percent for threshold 2

Command Modes

Interface configuration

Command History

Release	Modification
12.0(7)XE	Support for this command was introduced on the Catalyst 6500 series switches.
12.1(1)E	Support for this command on the Catalyst 6500 series switches was extended to the 12.1 E release.

Usage Guidelines

Use the transmit queue and threshold numbers.

The queue-id is 1 for the standard low-priority queue and 2 for the standard high-priority queue.

Always set threshold 2 to 100 percent.

Receive-queue drop thresholds are supported only on Gigabit Ethernet interfaces configured to trust CoS.

Examples

This example shows how to configure receive queue 1/threshold 1 and transmit queue 1/threshold 1:

Router(config-if)# wrr-queue threshold 1 60 100 

Router(config-if)#

Related Commands

show queueing interface
wrr-queue queue-limit