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Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX
OL-4266-08
Chapter 42 Configuring PFC3BXL or PFC3B Mode MPLS QoS
PFC3BXL or PFC3B Mode MPLS QoS Features
based on the EXP bits in the received topmost label of received MPLS packets (after a policy is
installed). See the
“Configuring a Class Map to Classify MPLS Packets” section on page 42-20
for
information.
Policing and Marking
Policing causes traffic that exceeds the configured rate to be discarded or marked down to a higher drop
precedence. Marking is a way to identify packet flows to differentiate them. Packet marking allows you
to partition your network into multiple priority levels or classes of service.
The PFC3BXL or PFC3B mode MPLS QoS policing and marking features that you can implement
depend on the received traffic type and the forwarding operation applied to the traffic. See
“Configuring
a Policy Map” section on page 42-23
for information.
Preserving IP ToS
The PFC3BXL or PFC3B automatically preserves the IP ToS during all MPLS operations including
imposition, swapping, and disposition.You do not need to enter a command to save the IP ToS.
EXP Mutation
You can configure a named egress EXP mutation map to mutate the internal DSCP-derived EXP value
before it is used as the egress EXP value. You can attach egress EXP mutation maps to these interface
types:
•
Optical service module (OSM) ports
•
LAN or OSM port subinterfaces
•
Layer 3 VLAN interfaces
•
Layer 3 LAN ports
You cannot attach EXP mutation maps to these interface types:
•
Layer 2 LAN ports (switchports)
•
FlexWAN ports or subinterfaces
For configuration information, see the
“Configuring PFC3BXL or PFC3B Mode MPLS QoS Egress EXP
Mutation” section on page 42-29
.
MPLS DiffServ Tunneling Modes
The PFC3BXL or PFC3B uses MPLS DiffServ tunneling modes. Tunneling provides QoS transparency
from one edge of a network to the other edge of the network. See the
“MPLS DiffServ Tunneling Modes”
section on page 42-32
for information.
