Understanding How PFC QoS Works
These figures provide more detail about the relationship between QoS and the switch components:
•
•
Figure 38-2
Figure 38-2
Traffic Flow and PFC QoS Features with PFC3B
FlexWAN traffic
enters switch
LAN traffic
enters switch
Figure 38-2
•
•
•
Catalyst Supervisor Engine 32 PISA Cisco IOS Software Configuration Guide, Release 12.2ZY
38-4
Figure
38-2,
Traffic Flow and PFC QoS Features with PFC3B
Figure
38-3,
PFC QoS Features and Component Overview
shows traffic flow and PFC QoS features with a PFC3B.
FlexWAN
(Routing only)
ingress port and
QoS features
LAN ingress
Ingress
port and
PFC3
QoS features
QoS
shows how traffic flows through the PFC QoS features with PFC3B:
Traffic can enter on any type of port and exit on any type of port.
For FlexWAN module traffic:
Ingress FlexWAN QoS features can be applied to FlexWAN ingress traffic.
–
Ingress FlexWAN traffic can be Layer 3-switched by the PFC3B or routed in software by the PISA.
–
Egress PFC QoS is not applied to FlexWAN ingress traffic.
–
Egress FlexWAN QoS can be applied to FlexWAN egress traffic.
–
For LAN-port traffic:
–
Ingress LAN-port QoS features can be applied to LAN-port ingress traffic.
–
Ingress PFC QoS can be applied to LAN-port ingress traffic (not supported with
PISA-accelerated features).
–
Ingress LAN-port traffic can be Layer-2 or Layer-3 switched by the PFC3B or routed in
software by the PISA.
Egress PFC QoS and egress LAN-port QoS can be applied to LAN-port egress traffic (not
–
supported with PISA-accelerated features).
PISA
Routing
NBAR or FPM
Egress
PFC3
PFC3
Layer 2 or 3
QoS
switching
Chapter 38
Configuring PFC QoS
FlexWAN
Transmit
egress port and
FlexWAN traffic
QoS features
CoS = IP precedence for all traffic
(not configurable)
LAN egress
Transmit
port and
LAN traffic
QoS features
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