Cisco Systems 4500 Marking Action Drivers

37-71
Software Configuration Guide—Release 15.0(2)SG
OL-23818-01
Chapter 37 Configuring Quality of Service Configuring QoS on Supervisor Engine 6-E, Supervisor Engine 6L-E, Catalyst 4900M, and Catalyst 4948E
For information on configuring a policy map, see the “Creating a Policy Map” section on page 37-31.
The final task is to attach the policy map to the interface. For information on attaching the policy map
to the interface, see the “Attaching a Policy Map to an Interface” section on page 37-35.
Method Two—Unconditional table map-based marking
You can create a table map that can be used to mark traffic attributes. A table map is a type of two-way
conversion chart that lists and maps one traffic attribute to another. A table map supports a many-to-one
type of conversion and mapping scheme. The table map establishes a to-from relationship for the traffic
attributes and defines the change to be made to the attribute. An attribute is set to one value that is taken
from another value. The values are based on the specific attribute being changed. For instance, the
Precedence attribute can be a number from 0 to 7, while the DSCP attribute can be a number from 0 to 63.
The following is a sample table map configuration:
table-map table-map1
map from 0 to 1
map from 2 to 3
exit
Table 37-7 lists the traffic attributes for which a to-from relationship can be established using the table
map.
The following is an example of a policy map (policy2) configured to use the table map (table-map1)
created earlier:
Policy map policy
class class-default
set cos dscp table table-map
exit
In this example, a mapping relationship was created between the CoS attribute and the DSCP attribute
as defined in the table map.
For information on configuring a policy map to use a table map, “Configuring a Policy Map” section on
page 37-31.
The final task is to attach the policy map to the interface. For information on attaching the policy map
to the interface, see the “Attaching a Policy Map to an Interface” section on page 37-35.
Marking Action Drivers
A marking action can be triggered based on one of the two QoS processing steps:
• Classification-based—All the traffic matching a class is marked using either explicit or table
map-based method. This method is referred to as unconditional marking.
• Policer result-based—A class of traffic is marked differently based on the policer result
(conform/exceed/violate) applicable to that packet. This method is referred to as conditional
marking.
Table 37-7 Traffic Attributes for Which a To-From Relationship Can Be Established
The To Attribute The From Attribute
Precedence CoS, QoS group, DSCP, Precedence
DSCP CoS, QoS group, DSCP, Precedence
CoS DSCP, QoS group, CoS, Precedence