EVC Quality of Service
This document contains information about how to enable quality of service (QoS) features (such as traffic classification and traffic policing) for use on an Ethernet virtual circuit (EVC).
An EVC as defined by the Metro Ethernet Forum is a port-level point-to-point or multipoint-to-multipoint circuit. It is an end-to-end representation of a single instance of a service being offered by a provider to a customer. It embodies the different parameters on which the service is being offered.
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the "Feature Information for Configuring EVC Quality of Service" section.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Contents
•Information About Quality of Service on an EVC
•How to Configure a Quality of Service Feature on an EVC
•Configuration Examples for EVC Quality of Service
•Feature Information for Configuring EVC Quality of Service
Information About Quality of Service on an EVC
•EVC Quality of Service and the MQC
•QoS-Aware Ethernet Flow Point (EFP)
•input and output Keywords of the service-policy Command
EVC Quality of Service and the MQC
QoS functionality is typically applied using traffic classes, class maps, and policy maps. For example, you can specify that traffic belonging to a particular class be grouped into specific categories, and receive a specific QoS treatment (such as classification or policing). The QoS treatment the traffic is to receive is specified in a policy map and the policy map is attached to an interface. The mechanism used for applying QoS in this manner is the modular QoS CLI (MQC.)
The policy map can be attached to an interface in either the incoming (ingress) or outgoing (egress) direction with the service-policy command.
The MQC structure allows you to define a traffic class, create a traffic policy, and attach the traffic policy to an interface (in this case, an EVC).
The MQC structure consists of the following three high-level steps.
1. Define a traffic class by using the class-map command. A traffic class is used to classify traffic.
2. Create a traffic policy by using the policy-map command. (The terms traffic policy and policy map are often synonymous.) A traffic policy (policy map) contains a traffic class and one or more QoS features that will be applied to the traffic class. The QoS features in the traffic policy determine how to treat the classified traffic.
3. Attach the traffic policy (policy map) to the interface by using the service-policy command.
Note For more information about the MQC, including information about hierarchical policy maps and class maps, see the "Applying QoS Features Using the MQC" module.
QoS-Aware Ethernet Flow Point (EFP)
As described in the "EVC Quality of Service and the MQC" section, the MQC is used to apply one or more QoS features to network traffic. The last step in using the MQC is to attach the traffic policy (policy map) to an interface (in this case, an EVC) by using the service-policy command.
With the EVC Quality of Service feature, the service-policy command can be used to attach the policy map to an Ethernet Flow Point (EFP) in either the incoming (ingress) or outgoing (egress) direction of an EVC. This way, the EFP is considered to be "QoS-aware."
QoS Functionality and EVCs
The specific QoS functionality available on an EVC varies by Cisco IOS XE release but can include the following:
•Packet classification (for example, based on differentiated services code point (DSCP) value and QoS group identifier)
•Packet marking (for example, based on Class of Service (CoS) value)
•Traffic policing (two- and three-color and multiple actions)
•Bandwidth sharing
•Priority queueing (in the outbound direction on the EVC only)
•Weighted Random Early Detection (WRED)
The QoS functionality is enabled by using the appropriate commands listed in the following sections.
•match Commands Supported by EVC QoS for Classifying Traffic
•Commands Used to Enable QoS Features on the EVC
match Commands Supported by EVC QoS for Classifying Traffic
Table 1 lists some of the available match commands that can be used when classifying traffic on an EVC. The available match commands vary by Cisco IOS XE release. For more information about the commands and command syntax, see the Cisco IOS Quality of Service Solutions Command Reference.
Multiple match Commands in One Traffic Class
If the traffic class contains more than one match command, you need to specify how to evaluate the match commands. You specify this by using either the match-any or match-all keyword of the class-map command. Note the following points about the match-any and match-all keywords:
•If you specify the match-any keyword, the traffic being evaluated by the traffic class must match one of the specified criteria.
•If you specify the match-all keyword, the traffic being evaluated by the traffic class must match all of the specified criteria.
•If you do not specify either keyword, the traffic being evaluated by the traffic class must match all of the specified criteria (that is, the behavior of the match-all keyword is used).
Commands Used to Enable QoS Features on the EVC
The commands used to enable QoS features vary by Cisco IOS XE release. Table 2 lists some of the available commands and the QoS features that they enable. For complete command syntax, see the Cisco IOS Quality of Service Solutions Command Reference.
For more information about a specific QoS feature that you want to enable, see the appropriate module of the Cisco IOS Quality of Service Solutions Configuration Guide.
input and output Keywords of the service-policy Command
As a general rule, the QoS features configured in the traffic policy can be applied to packets entering the interface or to packets leaving the interface. Therefore, when you use the service-policy command, you need to specify the direction of the traffic policy by using the input or output keyword.
For instance, the service-policy output policy-map1 command would apply the QoS features in the traffic policy to the interface in the output direction. All packets leaving the interface (output) are evaluated according to the criteria specified in the traffic policy named policy-map1.
Note For Cisco IOX XE Release 2.1 and later releases, queueing mechanisms are not supported in the input direction. Nonqueueing mechanisms (such as traffic policing and traffic marking) are supported in the input direction.
Also, classifying traffic on the basis of the source MAC address (using the match source-address mac command) is supported in the input direction only.
How to Configure a Quality of Service Feature on an EVC
•Creating a Traffic Class for Use on the EVC (required)
•Creating a Traffic Policy (Policy Map) for Use on the EVC (required)
•Configuring the EVC and Attaching a Traffic Policy to the EVC (required)
Creating a Traffic Class for Use on the EVC
To create a traffic class, use the class-map command to specify the traffic class name. Then use one or more match commands to specify the appropriate match criteria. Packets matching the criteria that you specify are placed in the traffic class.
To create the traffic class for use on the EVC, complete the following steps.
Note The match cos command shown in Step 4 is an example of a match command that you can use. For information about the other available match commands, see Table 1.
SUMMARY STEPS
1. enable
2. configure terminal
3. class-map [match-all | match-any] class-name
4. match cos cos-number
5. Enter additional match commands, if applicable; otherwise, continue with Step 6.
6. end
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Step 1 |
enable Router> enable |
Enables privileged EXEC mode. •Enter your password if prompted. |
Step 2 |
configure terminal Router# configure terminal |
Enters global configuration mode. |
Step 3 |
class-map [match-all | match-any] class-name Router(config)# class-map match-any class1 |
Creates a class map and enters class-map configuration mode. •The class map is used for matching packets to the specified class. Note The match-all keyword specifies that all match criteria must be met. The match-any keyword specifies that one of the match criteria must be met. Use these keywords only if you will be specifying more than one match command. |
Step 4 |
match cos cos-number Router(config-cmap)# match cos 2 |
Matches a packet on the basis of a Layer 2 CoS number. Note The match cos command is an example of a match command you can use. For information about the other match commands that are available, see Table 1. |
Step 5 |
Enter additional match commands, if applicable; otherwise, continue with Step 6. |
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Step 6 |
end Router(config-cmap)# end |
(Optional) Exits class map configuration mode and returns to privileged EXEC mode. |
DETAILED STEPS
Creating a Traffic Policy (Policy Map) for Use on the EVC
To create a traffic policy (or policy map) for use on the EVC, complete the following steps.
Note The police command shown in Step 5 is an example of one of the commands that you can use in a policy map. For information about other available commands, see Table 2.
SUMMARY STEPS
1. enable
2. configure terminal
3. policy-map policy-map-name
4. class {class-name | class-default}
5. police bps [burst-normal] [burst-max] [conform-action action] [exceed-action action] [violate-action action]
6. Enter the commands for any additional QoS feature that you want to enable on the EVC, as applicable; otherwise, continue with step 7.
7. end
DETAILED STEPS
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Step 1 |
enable Router> enable |
Enables privileged EXEC mode. •Enter your password if prompted. |
Step 2 |
configure terminal Router# configure terminal |
Enters global configuration mode. |
Step 3 |
policy-map policy-map-name Router(config)# |
Creates or specifies the name of the traffic policy and enters QoS policy-map configuration mode. |
Step 4 |
class {class-name | class-default} Router(config-pmap)# |
Specifies the name of a class and enters QoS policy-map class configuration mode. •Enter the class name created in the "Creating a Traffic Class for Use on the EVC" section Note This step associates the traffic class with the traffic policy. |
Step 5 |
police bps [burst-normal] [burst-max] [conform-action action] [exceed-action action] [violate-action action] Router(config-pmap-c)# police 3000 |
(Optional) Configures traffic policing. Note The police command is an example of a command that you can use in a policy map to enable a QoS feature. For information about the other commands available, see Table 2. |
Step 6 |
Enter the commands for any additional QoS feature that you want to enable, if applicable; otherwise, continue with Step 7. |
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Step 7 |
end Router(config-pmap-c)# end |
(Optional) Exits QoS policy-map class configuration mode and returns to privileged EXEC mode. |
Configuring the EVC and Attaching a Traffic Policy to the EVC
The traffic policy (policy map) applies the enabled QoS feature to the traffic class once you attach the policy map to the EVC.
To configure the EVC and attach a traffic policy to the EVC, complete the following steps.
Note One of the commands used to attach the traffic policy to the EVC is the service-policy command. When you use this command, you must specify either the input or output keyword along with the policy map name. The policy map contains the QoS feature you want to use. Certain QoS features can only be used in either the input or output direction. For more information about these keywords and the QoS features supported, see the "input and output Keywords of the service-policy Command" section.
Also, if you attach a traffic policy to an interface containing multiple EVCs, the traffic policy will be attached to all of the EVCs on the interface.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface interface-type interface-number
4. service instance id ethernet [evc-name]
5. encapsulation dot1q vlan-id [,vlan-id [-vlan-id]] [native]
6. rewrite ingress tag translate 1-to-1 dot1q vlan-id symmetric
7. bridge domain bridge-number
8. service-policy {input | output} policy-map-name
9. end
10. show policy-map interface type number service instance service-instance-number
DETAILED STEPS
Configuration Examples for EVC Quality of Service
•Example: Creating a Traffic Class for Use on the EVC
•Example: Creating a Traffic Policy (Policy Map) for Use on the EVC
•Example: Configuring the EVC and Attaching a Traffic Policy to the EVC
•Example: Verifying the Traffic Class and Traffic Policy Information for the EVC
Example: Creating a Traffic Class for Use on the EVC
In this example, traffic with a CoS value of 2 is placed in the traffic class called class1:
Router> enable
Router# configure terminal
Router(config)# class-map match-any class1
Router(config-cmap)# match cos 2
Router(config-cmap)# end
Example: Creating a Traffic Policy (Policy Map) for Use on the EVC
In this example, traffic policing has been configured in the policy map called policy1. Traffic policing is the QoS feature applied to the traffic in class1:
Router> enable
Router# configure terminal
Router(config)#
policy-map policy1
Router(config-pmap)#
class class1
Router(config-pmap-c)# police 3000
Router(config-pmap-c)# end
Example: Configuring the EVC and Attaching a Traffic Policy to the EVC
In this example, an EVC has been configured and a traffic policy called policy1 has been attached to the EVC:
Router> enable
Router# configure terminal
Router(config)# interface gigabitethernet 0/0/1
Router(config-if)# service instance 333 ethernet evc1
Router(config-if-srv)# encapsulation dot1q 10
Router(config-if-srv)# rewrite ingress tag translate 1-to-1 dot1q 300 symmetric
Router(config-if-srv)# bridge domain 1
Router(config-if-srv)# service-policy input policy1
Router(config-if-srv)# end
Example: Verifying the Traffic Class and Traffic Policy Information for the EVC
The following is sample output of the show policy-map interface service instance command. It displays the QoS features configured for and attached to the EFP on the GigabitEthernet interface 1/1/7.
Router# show policy-map interface gigabitethernet 1/1/7 service instance 10
GigabitEthernet1/1/7: EFP 10
Service-policy input: multiaction
Class-map: c1 (match-all)
0 packets, 0 bytes
5 minute offered rate 0000 bps, drop rate 0000 bps
Match: ip precedence 3
police:
cir 300000 bps, bc 2000 bytes
conformed 0 packets, 0 bytes; actions:
set-prec-transmit 7
set-qos-transmit 10
exceeded 0 packets, 0 bytes; actions:
drop
conformed 0000 bps, exceed 0000 bps
Class-map: class-default (match-any)
0 packets, 0 bytes
5 minute offered rate 0000 bps, drop rate 0000 bps
Match: any
Additional References
Related Documents
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Cisco IOS commands |
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QoS commands: complete command syntax, command modes, command history, defaults, usage guidelines, and examples |
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Packet classification |
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Packet marking |
"Marking Network Traffic" module |
MQC |
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EVC connections |
"Configuring Ethernet Virtual Connections on the Cisco ASR 1000 Router" module |
Standards
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MEF 6.1 |
Metro Ethernet Services Definitions Phase 2 (PDF 6/08) |
MIBs
RFCs
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No new or modified RFCs are supported, and support for existing RFCs has not been modified. |
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Technical Assistance
Feature Information for Configuring EVC Quality of Service
Table 3 lists the release history for this feature.
Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Note Table 3 lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.