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Document ID: 10470
Contents
Introduction
Prerequisites
Requirements
Hardware and Software Versions
Conventions
Configure
Network Diagram
Configurations
Verify
Troubleshoot
Related Information
Introduction
This document provides an addendum to the MPLS CoS Over ATM: Multi-VC TBR (with CAR) sample configuration.
It provides a Class of Service (CoS) map for the Multiprotocol Label Switching (MPLS) CoS mechanism. This shows how you can reduce the number of parallel link-state packets (LSPs) from four (the maximum and the default) to two (the minimum). It is sometimes necessary to do this in order to reduce the number of Label Virtual Circuits (LVCs) – or "Tag VCs" in old terminology – since there is a maximum number of VCs per ATM switch.
Note: This sample configuration uses access-list 1 permit any, but you can also apply a more specific access list, if necessary.
Prerequisites
Requirements
There are no specific requirements for this document.
Hardware and Software Versions
This configuration was developed and tested with these software and hardware versions:
Edge LSR
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Software - Cisco IOS® Software Release 12.1(3)T. The Multi-VC feature appeared in Cisco IOS Software Release 12.0(5)T.
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Hardware - Cisco 7200 Routers with PA-A1.
Note: This feature only works with Cisco 7200 and 7500 Routers with PA-A1.
Core ATM LSR
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Software - Any software release that supports MPLS: the latest versions are recommended.
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Hardware - The LightStream 1010 and 8540MSR.
Note: A feature card per-flow queueing (FC-PFQ) is mandatory for the LightStream 1010.
The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.
Conventions
Refer to Cisco Technical Tips Conventions for more information on document conventions.
Configure
In this section, you are presented with the information to configure the features described in this document.
Note: Use the Command Lookup Tool (registered customers only) to find more information on the commands used in this document.
Network Diagram
This document uses this network setup:
Configurations
Add these lines to the configuration described in MPLS CoS Over ATM: Multi-VC TBR (with CAR). As with the main configuration, add these lines to the edge Label Switch Routers (LSRs). In this example, it is Alcazaba and Ischia.
Note: Make sure that you issue configuration commands in general configuration mode.
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Alcazaba and Ischia |
|---|
Current configuration: ! tag-switching prefix-map 1 access-list 1 cos-map 1 ! tag-switching cos-map 1 class 0 available class 1 available class 2 premium class 3 premium ! access-list 1 permit any ! |
Verify
Use this section to confirm that your configuration works properly.
The Output Interpreter Tool (registered customers only) (OIT) supports certain show commands. Use the OIT to view an analysis of show command output.
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show tag-switching cos-map
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show tag-switching prefix-map
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show access-lists
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show tag-switching forwarding-table <destination> <mask> detail
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show tag-switching atm-tdp binding <destination> <mask>
Use these commands to check the specific CoS mapping enabled on the edge LSRs:
Alcazaba#show tag-switching cos-map
cos-map 1 class tag-VC
3 premium
2 premium
1 available
0 available
Alcazaba#show tag-switching prefix-map
prefix-map 1 access-list 1 cos-map 1
Alcazaba#show access-lists
Standard IP access list 1
permit any
Use these commands to check if the parallel LSPs are set up accordingly.
Use the first command on one of the edge LSRs:
Alcazaba#show tag-switching forwarding-table 2.2.2.2 32 detail
Local Outgoing Prefix Bytes tag Outgoing Next Hop
tag tag or VC or Tunnel Id switched interface
25 Multi-VC 2.2.2.2/32 0 AT4/0.1 point2point
available 2/33(910), standard 2/33(910), premium 2/34(911), control 2/34(911),
MAC/Encaps=4/8, MTU=4470, Tag Stack{Multi-VC}
04FD8847 004FD000
Per-packet load-sharing
Use the second command on an ATM switch on the core:
Capri#show tag atm-tdp bind 2.2.2.2 32
Destination: 2.2.2.2/32
Transit ATM3/0/2 2/33 Active -> ATM3/1/2 2/77 Active, CoS=available
Transit ATM3/0/2 2/34 Active -> ATM3/1/2 2/78 Active, CoS=premium
Troubleshoot
There is currently no specific troubleshooting information available for this configuration.
Related Information
| Updated: Jun 05, 2005 | Document ID: 10470 |