Queueing And Scheduling Of Ingress Queues - Cisco Catalyst 3750 Software Configuration Manual

Metro switch

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Table of Contents

Configuring QoS

Queueing and Scheduling of Ingress Queues

Figure 26-7 Ingress Queueing and Scheduling Flowchart

(DSCP or CoS value).

Determine ingress queue

number, buffer allocation,

and WTD thresholds.

Queue the packet. Service

the queue according to

SRR services the priority queue for its configured share before servicing the other queue.

The switch supports two configurable ingress queues, which are serviced by SRR in shared mode only.

Table 26-1 Ingress Queue Types

1. The switch uses two nonconfigurable queues for traffic that is essential for proper network operation.

shows the ingress queueing and scheduling flowchart.

Read QoS label

Are thresholds

being exceeded?

the SRR weights.

Send packet to

the internal ring.

describes the queues.

User traffic that is considered to be normal priority. You can configure three different

thresholds to differentiate among the flows. You can use the mls qos srr-queue input

threshold, the mls qos srr-queue input dscp-map, and the mls qos srr-queue input

cos-map global configuration commands.

High-priority user traffic such as differentiated services (DF) expedited forwarding or

voice traffic. You can configure the bandwidth required for this traffic as a percentage

of the total traffic by using the mls qos srr-queue input priority-queue global

configuration command. The expedite queue has guaranteed bandwidth.

Drop packet.

Catalyst 3750 Metro Switch Software Configuration Guide

Understanding QoS