QoS Policy Support for L2VPN ATM PVPs

Last Updated: November 28, 2011

This document explains how to configure Quality of Service (QoS) Policy Support for Layer 2 Virtual Private Network (L2VPN) ATM permanent virtual paths (PVPs). That is, it explains how to configure QoS policies in ATM PVP mode for L2VPNs.

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 Table at the end of this document.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.

Prerequisites for QoS Policy Support for L2VPN ATM PVPs

Before configuring QoS policies on L2VPN ATM PVPs, you should understand the concepts and configuration instructions in the following document:

  • Any Transport over MPLS

Restrictions for QoS Policy Support for L2VPN ATM PVPs

The following restrictions apply to the QoS Policy Support for L2VPN ATM PVPs feature:

  • The Cisco 7600 series router does not support any queueing features in ATM PVP mode.
  • When you enable a policy in PVP mode, do not configure ATM rates on the VCs that are part of the PVP. The VCs should be unspecified bit rate (UBR) VCs only.
  • If VCs are part of a PVP that has a policy configured, you cannot configure ATM VC traffic shaping.
  • Cisco IOS Release 12.2(33)SRE does not support cell-based ATM shaping per PVP.
  • You cannot configure a queueing policy on an ATM PVP with UBR.
  • You cannot configure queueing-based policies with UBR traffic shaping.

Information About QoS Policy Support for L2VPN ATM PVPs

MQC Structure

The modular QoS command-line interface (CLI) (MQC) structure allows you to define a traffic class, create a traffic policy, and attach the traffic policy to an interface.

The MQC structure is the result of the following these three high-level steps.

  1. Define a traffic class by using the class-mapcommand. 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.

Elements of a Traffic Class

A traffic class contains three major elements: a traffic class name, a series of match commands, and, if more than one match command is used in the traffic class, instructions on how to evaluate these match commands.

The match commands are used for classifying packets. Packets are checked to determine whether they meet the criteria specified in the match commands; if a packet meets the specified criteria, that packet is considered a member of the class. Packets that fail to meet the matching criteria are classified as members of the default traffic class.

Elements of a Traffic Policy

A traffic policy contains three elements: a traffic policy name, a traffic class (specified with the class command), and the command used to enable the QoS feature.

The traffic policy (policy map) applies the enabled QoS feature to the traffic class once you attach the policy map to the interface (by using the service-policy command).


Note
A packet can match only one traffic class within a traffic policy. If a packet matches more than one traffic class in the traffic policy, the first traffic class defined in the policy will be used.

How to Configure QoS Policy Support for L2VPN ATM PVPs

Enabling a Service Policy in ATM PVP Mode

You can enable a service policy in ATM PVP mode. You can also enable a service policy on PVP on a multipoint subinterface.


Note
  • The Cisco 7600 series router does not support a service policy that uses the match atm-vcicommand in the egress direction.
  • The show policy-map interface command does not display service policy information for ATM interfaces.
  • Cisco IOS Release 12.2(33)SRE does not support cell-based ATM shaping per PVP.
>
SUMMARY STEPS

1.    enable

2.    configure terminal

3.    interface atm slot/port

4.    atm pvp vpi l2transport

5.    service-policy [input | output] policy-map-name

6.    xconnect peer-router-id vcid encapsulation mpls

7.    end


DETAILED STEPS
  Command or Action Purpose
Step 1
enable


Example:

Router> enable

 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2
configure terminal


Example:

Router# configure terminal

 

Enters global configuration mode.

 
Step 3
interface atm slot/port

Example:

Router(config)# interface atm 1/0

 

Defines the interface and enters interface configuration mode.

 
Step 4
atm pvp vpi l2transport


Example:

Router(config-if)# atm pvp 1 l2transport

 

Specifies that the PVP is dedicated to transporting ATM cells and enters l2transport PVP configuration mode.

  • The l2transport keyword indicates that the PVP is for cell relay. This mode is for Layer 2 transport only; it is not for regular PVPs.
 
Step 5
service-policy [input | output] policy-map-name


Example:

Router(config-if-atm-l2trans-pvp)# service policy input pol1

 

Enables a service policy on the specified PVP.

 
Step 6
xconnect peer-router-id vcid encapsulation mpls

Example:

Router(config-if-atm-l2trans-pvp)# xconnect 10.0.0.1 123 encapsulation mpls

 

Binds the attachment circuit to a pseudowire VC.

  • The syntax for this command is the same as for all other Layer 2 transports.
 
Step 7
end


Example:

Router(config-if-atm-l2trans-pvp)# end

 

Exits l2transport PVP configuration mode and returns to privileged EXEC mode.

 

Enabling Traffic Shaping in ATM PVP Mode

Traffic shaping commands are supported in ATM PVP mode. For egress VP shaping, one configuration command is supported for each ATM service category. The supported service categories are constant bit rate (CBR), UBR, variable bit rate-nonreal time (VBR-NRT), and variable bit rate real-time (VBR-RT).


Note
  • The Cisco 7600 series router does not support traffic shaping.
  • Cisco IOS Release 12.2(33)SRE does not support cell-based ATM shaping per PVP.
>
SUMMARY STEPS

1.    enable

2.    configure terminal

3.    interface atm slot/port

4.    atm pvp vpi l2transport

5.   Do one of the following:

  • ubr pcr
  • cbr pcr
  • or
  • vbr-nrt pcr scr mbs
  • or
  • vbr-rt pcr scr mbs

6.    xconnect peer-router-id vcid encapsulation mpls


DETAILED STEPS
  Command or Action Purpose
Step 1
enable


Example:

Router> enable

 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2
configure terminal


Example:

Router# configure terminal

 

Enters global configuration mode.

 
Step 3
interface atm slot/port

Example:

Router(config)# interface atm 1/0

 

Defines the interface and enters interface configuration mode.

 
Step 4
atm pvp vpi l2transport


Example:

Router(config-if)# atm pvp 1 l2transport

 

Specifies that the PVP is dedicated to transporting ATM cells, and enters l2transport PVP configuration mode.

  • The l2transport keyword indicates that the PVP is for cell relay. This mode is for Layer 2 transport only; it is not for regular PVPs.
 
Step 5
Do one of the following:
  • ubr pcr
  • cbr pcr
  • or
  • vbr-nrt pcr scr mbs
  • or
  • vbr-rt pcr scr mbs


Example:

Router(config-if-atm-l2trans-pvp)# cbr 1000



Example:



Example:

cbr 56



Example:



Example:

vbr-nrt 11760 11760 1



Example:



Example:

vbr-rt 640 320 80

 

Enables traffic shaping in ATM PVP mode.

  • pcr = peak cell rate
  • scr = sustain cell rate
  • mbs = maximum burst size
 
Step 6
xconnect peer-router-id vcid encapsulation mpls

Example:

Router(config-if-atm-l2trans-pvp)# xconnect 10.0.0.1 123 encapsulation mpls

 

Binds the attachment circuit to a pseudowire VC.

  • The syntax for this command is the same as for all other Layer 2 transports.
 

Enabling Matching of ATM VCIs

You can enable packet matching on an ATM VCI or range of VCIs using the match atm-vci command in class map configuration mode.


Note
  • When you configure the match atm-vcicommand in class map configuration mode, you can add this class map to a policy map that can be attached only to an ATM VP.
  • On the Cisco 7600 series router, the match atm-vcicommand is supported only in the ingress direction on an ATM VP.
  • Cisco IOS Release 12.2(33)SRE does not support cell-based ATM shaping per PVP.
>
SUMMARY STEPS

1.    enable

2.    configure terminal

3.    class-map class-map-name [match-all | match-any]

4.    match atm-vci vc-id [- vc-id]

5.    end


DETAILED STEPS
  Command or Action Purpose
Step 1
enable


Example:

Router> enable

 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2
configure terminal


Example:

Router# configure terminal

 

Enters global configuration mode.

 
Step 3
class-map class-map-name [match-all | match-any]


Example:

Router(config)# class-map class1

 

Creates a class map to be used for matching traffic to a specified class, and enters class map configuration mode.

 
Step 4
match atm-vci vc-id [- vc-id]


Example:

Router(config-cmap)# match atm-vci 50

 

Enables packet matching on an ATM VCI or range of VCIs.

  • The range is 32 to 65535.
Note    You can use the match not command to match any VC except those you specify in the command.
 
Step 5
end


Example:

Router(config-cmap)# end

 

(Optional) Returns to privileged EXEC mode.

 

Configuration Examples for QoS Policy Support for L2VPN ATM PVPs

Enabling Traffic Shaping in ATM PVP Mode Example

The following example enables traffic shaping in ATM PMP mode.

interface atm 1/0
 atm pvp 100 l2transport
  ubr 1000
  xconnect 10.11.11.11 777 encapsulation mpls
 atm pvp 101 l2transport
  cbr 1000
  xconnect 10.11.11.11 888 encapsulation mpls
 atm pvp 102 l2transport
  vbr-nrt 1200 800 128
  xconnect 10.11.11.11 999 encapsulation mpls

Additional References

The following sections provide references related to the QoS Policy Support for L2VPN ATM PVPs feature.

Related Documents

Related Topic

Document Title

Cisco IOS commands

Cisco IOS Master Commands List, All Releases

MPLS commands

Cisco IOS Multiprotocol Label Switching Command Reference

Any Transport over MPLS

Any Transport over MPLS

Standards

Standard

Title

None

--

MIBs

MIB

MIBs Link

  • None

To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:

http://www.cisco.com/go/mibs

RFCs

RFC

Title

None

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Technical Assistance

Description

Link

The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies.

To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds.

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Feature Information for QoS Policy Support for L2VPN ATM PVPs

The following table provides release information about the feature or features described in this module. This table 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.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.

Table 1 Feature Information for QoS Policy Support for L2VPN ATM PVPs

Feature Name

Releases

Feature Information

QoS Policy Support for L2VPN ATM PVPs

12.2(33)SRE

This feature enables you to configure QoS policies in ATM PVP mode for L2VPNs.

The following commands were introduced or modified by this feature: cbr, match atm-vci, service-policy, ubr, vbr-nrt, vbr-rt.

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Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.

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