Traffic Class Elements; Traffic Policy Elements - Cisco ASR 9000 Series Configuration Manual

Configuring Modular Quality of Service Packet Classification on Cisco ASR 9000 Series Routers
IPv6-based classification is supported only on Layer 3 interfaces.
Note

Traffic Class Elements

The purpose of a traffic class is to classify traffic on your router. Use the class-map command to define
a traffic class.
A traffic class contains three major elements: a name, a series of match commands, and, if more than
one match command exists in the traffic class, an instruction on how to evaluate these match commands.
The traffic class is named in the class-map command. For example, if you use the word cisco with the
class-map command, the traffic class would be named cisco.
The match commands are used to specify various criteria for classifying packets. Packets are checked
to determine whether they match the criteria specified in the match commands. If a packet matches the
specified criteria, that packet is considered a member of the class and is forwarded according to the QoS
specifications set in the traffic policy. Packets that fail to meet any of the matching criteria are classified
as members of the default traffic class. See the
The instruction on how to evaluate these match commands needs to be specified if more than one match
criterion exists in the traffic class. The evaluation instruction is specified with the class-map match-any
command. If the match-any option is specified as the evaluation instruction, the traffic being evaluated
by the traffic class must match at least one of the specified criteria. The match-any keyword is the only
evaluation option supported. If the match-all option is specified, the traffic must match all of the match
criteria.
The function of these commands is described more thoroughly in the Cisco ASR 9000 Series
Aggregation Services Router Modular Quality of Service Command Reference.
The traffic class configuration task is described in the

Traffic Policy Elements

The purpose of a traffic policy is to configure the QoS features that should be associated with the traffic
that has been classified in a user-specified traffic class or classes. The policy-map command is used to
create a traffic policy. A traffic policy contains three elements: a name, a traffic class (specified with the
class command), and the QoS policies. The name of a traffic policy is specified in the policy map
Modular Quality of Service (MQC) (for example, the policy-map policy1 command creates a traffic
policy named policy1). The traffic class that is used to classify traffic to the specified traffic policy is
defined in class map configuration mode. After choosing the traffic class that is used to classify traffic
to the traffic policy, the user can enter the QoS features to apply to the classified traffic.
The MQC does not necessarily require that users associate only one traffic class to one traffic policy.
When packets match to more than one match criterion, as many as 512 traffic classes can be associated
to a single traffic policy. The 512 class maps include the default class and the classes of the child policies,
if any.
The order in which classes are configured in a policy map is important. The match rules of the classes
are programmed into the TCAM in the order in which the classes are specified in a policy map.
Therefore, if a packet can possibly match multiple classes, only the first matching class is returned and
the corresponding policy is applied.
The function of these commands is described more thoroughly in the Cisco ASR 9000 Series
Aggregation Services Router Modular Quality of Service Command Reference.
OL-17239-01
Information About Configuring Modular QoS Packet Classification on Cisco ASR 9000 Series Routers
D r a f t — C i s c o C o n f i d e n t i a l
Cisco ASR 9000 Series Aggregation Services Router Modular Quality of Service Configuration Guide
"Default Traffic Class" section on page
"Creating a Traffic Class" section on page
10.
13.
QC-9