52-5
Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
OL-8978-04
Chapter 52 Configuring QoS
Understanding How QoS Works
Figure 52-3
Ethernet ingress Port Classification, Marking, Scheduling, and Congestion Avoidance
68001
Yes
Frame
enters
switch
Port set to
untrusted?
ISL or
802.1Q?
Drop thresholds
Apply
port
CoS
No
No
Yes
Port set to
trust-ipprec?
Port set to
trust-dscp?
No
No
Port is set to
trust-cos
To
switching engine
Apply
port
CoS
Ethernet ingress port classification, marking,
scheduling, and congestion avoidance
Yes
Yes