Cisco WS-SUP32-GE-3B - Supervisor Engine 32 Software Configuration Manual page 543

Chapter 38 Configuring PFC QoS
Figure 38-5
Figure 38-5 QoS Features on the PFC3B
For trust CoS traffic:
CoS
(Received or Port)
For trust DSCP traffic:
Received
DSCP
For trust IP precedence traffic:
Received IP
Precedence
For untrusted traffic or
for any traffic if ignore
port trust is configured
When ignore port trust is not configured
When ignore port trust is configured,
received DSCP (if any) is initial internal
DSCP, otherwise port CoS is mapped
to initial internal DSCP
Note The
OL-11439-03
shows how traffic flows through the QoS features on the PFC3B.
Ingress PFC QoS
Policy map
Initial
Map
Internal
DSCP
(Optional)
Policy map
Initial
Internal
DSCP
(Optional)
Policy map
Initial
Internal
Map
DSCP
(Optional)
Policy map
Initial Internal DSCP=0
(Optional)
DSCP transparency feature makes writing the egress DSCP value into the Layer 3 ToS byte optional.
Catalyst Supervisor Engine 32 PISA Cisco IOS Software Configuration Guide, Release 12.2ZY
Policer
Marker
Policer
Marker
Traffic Forwarding
PISA processing
or
PFC Layer 3
switching
or
PFC Layer 2
Policer
switching
Marker
Policer
Marker
Understanding How PFC QoS Works
Egress PFC QoS
Egress
DSCP
Policy map
Mutation
Final
Policer
Map
Internal
Marker
DSCP
(only on PFC3)
(Optional;
only
Map
with PFC 3)
Egress
DSCP
Egress CoS
(LAN ports only)
38-9