Mls Qos Srr-Queue Input Priority-Queue - Cisco Catalyst 3750 Command Reference Manual

Chapter 2 Catalyst 3750 Switch Cisco IOS Commands

mls qos srr-queue input priority-queue

Use the mls qos srr-queue input priority-queue global configuration command on the switch stack or
on a standalone switch to configure the ingress priority queue and to guarantee bandwidth on the stack
ring if the ring is congested. Use the no form of this command to return to the default setting.
Syntax Description
queue-id
bandwidth weight
Defaults The priority queue is queue 2, and 10 percent of the bandwidth is allocated to it.
Command Modes
Global configuration
Command History Release
12.1(11)AX
Usage Guidelines
You should use the priority queue only for traffic that needs to be expedited (for example, voice traffic,
which needs minimum delay and jitter).
The priority queue is guaranteed part of the bandwidth on the stack ring, which reduces the delay and
jitter under heavy network traffic on an oversubscribed stack (when there is more traffic than the
backplane can carry, and the queues are full and dropping frames).
The amount of bandwidth that can be guaranteed is restricted because a large value affects the entire
stack and can degrade the stack performance.
Shaped round robin (SRR) services the priority queue for its configured weight as specified by the
bandwidth keyword in the mls qos srr-queue input priority-queue queue-id bandwidth weight global
configuration command. Then SRR shares the remaining bandwidth with both ingress queues and
services them as specified by the weights configured with the mls qos srr-queue input bandwidth
weight1 weight2 global configuration command.
To disable priority queueing, set the bandwidth weigh to 0, for example, mls qos srr-queue input
priority-queue queue-id bandwidth 0.
Examples This example shows how to assign the ingress bandwidths for the queues in the stack. Queue 1 is the
priority queue with 10 percent of the bandwidth allocated to it. The bandwidth ratio allocated to queues
1 and 2 is 4/(4+4). SRR services queue 1 (the priority queue) first for its configured 10 percent
bandwidth. Then SRR equally shares the remaining 90 percent of the bandwidth between queues 1 and
2 by allocating 45 percent to each queue:
Switch(config)# mls qos srr-queue input priority-queue 1 bandwidth 10
78-16181-03
mls qos srr-queue input priority-queue queue-id bandwidth weight
no mls qos srr-queue input priority-queue queue-id
Ingress queue ID. The range is 1 to 2.
Bandwidth percentage of the stack ring. The range is 0 to 40.
Modification
This command was introduced.
mls qos srr-queue input priority-queue
Catalyst 3750 Switch Command Reference
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