User`s guide

212 XSR User’s Guide
Mechanisms to Provide QoS Chapter 10
Configuring Quality of Service
You must perform three steps to configure a class-based classifier:
1
Define a traffic class with the class-map command.
2 Create a traffic policy by associating the traffic class with one or more
QoS features (using the
policy-map command).
3 Attach the traffic policy to the port or DLCI with the service-policy
command.
A QoS policy-map for DLCI defines a set of complex rules to identify classes
of traffic and then applies service policies to them. Use the traffic-class-map to
group a set of simple rules to form a set of complex rules. You can define
complex rules with a combination of matching criteria and, at the same time,
not matching other criteria.
Describing the Class Map
The traffic class map builds complex rules with matching criteria. Multiple
rules can be specified by a given traffic class-map using the
class-map
command, but all rules in the given class map must be configured to use the
same matching criteria:
 match-any
 match-all
The following traffic class map defines the match-all class-map abc. A packet
that satisfies the criteria defined in access-group 2 and has a DSCP value set
to 32 is considered a part of this traffic class. In a match-all class-map all
criteria must be met in order for the packet to be assigned to the class.
XSR(config)#access-list 2 permit 15.15.15.0 0.0.0.255
XSR(config)#class-map match-all abc
XSR(config-cmap<abc>)#match access-group 2
XSR(config-cmap<abc>)#match ip dscp 32
In a match-any class-map, one or more criteria of the class-map must be met in
order for packets to be assigned to the class. For example, if class-map ABC
were a match-any class-map, packets arriving with a source address of
15.15.15.3, with Layer 3 protocol IP and DSCP value of 12 assigned, would be
classified as class ABC since it matches access-list 2.