Permanent Virtual Circuits (PVC) and Switched Virtual Circuits (SVC)

Document ID: 10487

Contents

Introduction
Prerequisites
      Requirements
      Components Used
      Conventions
Configure
      Network Diagram
      Configurations
Verify
Troubleshoot
Related Information

Introduction

This document shows how to configure Point-to-Multipoint Permanent Virtual Connections (PVC) on Cisco LightStream 1010s, Catalyst 8510MSRs and Catalyst 8540MSRs. It also looks at how to implement traffic policing configurations on this type of PVC.

The typical application for Point-to-Multipoint PVCs is video stream that needs to go to multiple destinations. The flow of cells is unidirectional from one PVC (root) to multiple PVCs (leaf). Multiple destinations are made possible by replicating the cells from the root PVC and sending them over to the leaf PVCs.

Prerequisites

Requirements

There are no specific requirements for this document.

Components Used

The information in this document is based on these software and hardware versions:

• Cisco LightStream 1010

• Catalyst 8510MSR

• Catalyst 8540MSR

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

For more information on document conventions, refer to Cisco Technical Tips Conventions.

Configure

In this section, you are presented with the information to configure the features described in this document.

Note: To find additional information on the commands used in this document, use the Command Lookup Tool (registered customers only) .

Network Diagram

This document uses this network setup:

Note: The commands are the same across LightStream 1010 and Catalyst 8500MSR switches.

Configurations

This configuration creates a single root PVC and multiple leaf PVCs.

interface ATM0/0/0 
 no ip address
 no ip directed-broadcast 
 atm pvc 50 100 cast-type p2mp-root interface ATM0/1/0 60 200 cast-type p2mp-leaf
 atm pvc 50 100 cast-type p2mp-root interface ATM0/1/1 70 210 cast-type p2mp-leaf
 atm pvc 50 100 cast-type p2mp-root interface ATM0/1/2 80 220 cast-type p2mp-leaf
!
interface ATM0/1/0 
 no ip address 
 no ip directed-broadcast 
!
interface ATM0/1/1 
 no ip address 
 no ip directed-broadcast 
!
interface ATM0/1/2 
 no ip address 
 no ip directed-broadcast 
!

The second configuration enables traffic policing on the point-to-multipoint PVC. Since it is unidirectional, the point-to-multipoint PVC still requires two entries from the ATM connection traffic table row (CTTR) index. One is for the forward direction and one is for the backward direction. Refer to Configuring the Connection Traffic Table for more information. The backward direction must have zero traffic rate. Failure to do so results in this error message:

%connection creation fails: bad parameters

The zero traffic rate for the backward direction is a strict requirement on all service classes. This includes constant bit rate (CBR), variable bit rate (VBR) and available bit rate (ABR) except for unspecified bit rate (UBR). This restriction for UBR has been removed due to interoperability issues with other vendors' equipment. UBR traffic policing can use non-zero traffic rate on the backward direction. This is documented under Cisco bug ID CSCdv20934 (registered customers only) .

This output is a sample configuration of traffic policing point-to-multipoint PVC using CBR service class and 10 Mbps for the Peak Cell Rate (PCR). All non-compliant cells are tagged (the Cell Loss Priority (CLP) bit is set).

atm connection-traffic-table-row index 100 cbr pcr 10000
atm connection-traffic-table-row index 101 cbr pcr 0
interface ATM0/0/0 
 no ip address
 no ip directed-broadcast 
 atm pvc 50 100 cast-type p2mp-root rx-cttr 100 tx-cttr 101 upc tag 
 interface ATM0/1/0 60 200 cast-type p2mp-leaf rx-cttr 101 tx-cttr 100
 atm pvc 50 100 cast-type p2mp-root rx-cttr 100 tx-cttr 101 upc tag 
 interface ATM0/1/1 70 210 cast-type p2mp-leaf rx-cttr 101 tx-cttr 100
 atm pvc 50 100 cast-type p2mp-root rx-cttr 100 tx-cttr 101 upc tag 
 interface ATM0/1/2 80 220 cast-type p2mp-leaf rx-cttr 101 tx-cttr 100
!
interface ATM0/1/0 
 no ip address 
 no ip directed-broadcast 
!
interface ATM0/1/1 
 no ip address 
 no ip directed-broadcast 
!
interface ATM0/1/2 
 no ip address 
 no ip directed-broadcast 
!

Verify

This section provides information you can use to confirm your configuration is working properly.

Certain show commands are supported by the Output Interpreter Tool (registered customers only) , which allows you to view an analysis of show command output.

• show atm vc [interface]—Displays the source and destination VCs.

• show atm vc [interface] [vpi] [vci]—Displays the VC in detail.

• show atm connection-traffic-table—Displays all the configured connection-traffic-table-row indexes.

Switch#show atm vc interface atm0/0/0
Interface    VPI   VCI   Type    X-Interface  X-VPI X-VCI  Encap Status
ATM0/0/0     0     5      PVC     ATM2/0/0     0     39    QSAAL  UP
ATM0/0/0     0     16     PVC     ATM2/0/0     0     35    ILMI   UP
ATM0/0/0     50    100    PVC     ATM0/1/0     60    200          UP
                                  ATM0/1/1     70    210          UP
                                  ATM0/1/2     80    220          UP


Switch#show atm vc interface a0/0/0 50 100

Interface: ATM0/0/0, Type: oc3suni 
VPI = 50  VCI = 100
Status: DOWN
Time-since-last-status-change: 00:01:36
Connection-type: PVC 
Cast-type: point-to-multipoint-root
Packet-discard-option: disabled
Usage-Parameter-Control (UPC): tag
Number of OAM-configured connections: 0
OAM-configuration: disabled
OAM-states:  Not-applicable
Cross-connect-interface: ATM0/1/0, Type: oc3suni 
Cross-connect-VPI = 60 
Cross-connect-VCI = 200
Cross-connect-UPC: pass
Cross-connect OAM-configuration: disabled
Cross-connect OAM-state:  Not-applicable
Cross-connect-interface: ATM0/1/1
Cross-connect-VPI = 70 
Cross-connect-VCI = 210
Cross-connect-interface: ATM0/1/2
Cross-connect-VPI = 80 
Cross-connect-VCI = 220
Rx cells: 0, Tx cells: 0
Rx connection-traffic-table-index: 100
Rx service-category: CBR (Constant Bit Rate)
Rx pcr-clp01: 10000
Rx scr-clp01: none
Rx mcr-clp01: none
Rx      cdvt: 1024 (from default for interface)
Rx       mbs: none
Tx connection-traffic-table-index: 101
Tx service-category: CBR (Constant Bit Rate)
Tx pcr-clp01: 0
Tx scr-clp01: none
Tx mcr-clp01: none
Tx      cdvt: none
Tx       mbs: none 


Switch#show atm connection-traffic-table        
Row      Service-category    pcr        scr/mcr       mbs         cdvt
1            ubr          7113539        none                     none
2            cbr              424                                 none
3            vbr-rt           424         424          50         none
4            vbr-nrt          424         424          50         none
5            abr              424           0                     none
6            ubr              424        none                     none
100          cbr            10000                                 none
101          cbr                0                                 none
63999        cbr             1741                                 none
64000        cbr             1737                                 none
2147483643   cbr             1737                                 none
2147483644   cbr             1737                                 none
2147483645*  ubr                0        none                     none
2147483646*  ubr                1        none                     none
2147483647*  ubr          7113539        none                     none

Troubleshoot

There is currently no specific troubleshooting information available for this configuration.

Related Information

• Configuring Virtual Connections
• Configuring Resource Management
• ATM Technology Support Pages
• Technical Support - Cisco Systems