Queueing And Scheduling Overview - Cisco Catalyst 3750-E Software Configuration Manual

Understanding QoS

Queueing and Scheduling Overview

The switch has queues at specific points to help prevent congestion as shown in
Figure
Figure 37-6 Ingress and Egress Queue Location on Catalyst 3750-E Switches
Policer
Policer
Traffic
Classify
Policer
Policer
Figure 37-7 Ingress and Egress Queue Location on Catalyst 3560-E Switches
Policer
Policer
Traffic
Classify
Policer
Policer
Because the total inbound bandwidth of all ports can exceed the bandwidth of the stack or internal ring,
ingress queues are located after the packet is classified, policed, and marked and before packets are
forwarded into the switch fabric. Because multiple ingress ports can simultaneously send packets to an
egress port and cause congestion, outbound queues are located after the stack or internal ring.
Catalyst 3750-E and 3560-E Switch Software Configuration Guide
37-14
37-7.
Marker
Marker
Ingress
queues
Marker
Marker
Marker
Marker
Ingress
queues
Marker
Marker
Egress
queues
Stack ring
SRR
Internal Egress
ring queues
SRR
Chapter 37 Configuring QoS
Figure 37-6 and
SRR
SRR
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