Table of Contents

Configuring Virtual Connections

This chapter describes how to configure virtual connections (VCs) in a typical ATM network after autoconfiguration has established the default network connections. The network configuration modifications described in this chapter are used to optimize your ATM network operation.

Note   This chapter provides advanced configuration instructions for the Catalyst 8540 MSR, Catalyst 8510 MSR, and LightStream 1010 ATM switch routers. For an overview of virtual connection types and applications, refer to the . For complete descriptions of the commands mentioned in this chapter, refer to the publication.

The tasks to configure virtual connections are described in the following sections:

Characteristics and Types of Virtual Connections

This section lists the various virtual connections (VC) types in Table 6-1.

Configuring Virtual Channel Connections

This section describes configuring virtual channel connections (VCCs) on the ATM switch router. A VCC is established as a bidirectional facility to transfer ATM traffic between two ATM layer users. Figure 6-1 shows an example VCC between ATM user A and user D.

An end-to-end VCC, as shown in Figure 6-1 between user A and user D, has two parts:

The common endpoint between an internal connection and a link occurs at the switch interface. The endpoint of the internal connection is also referred to as a connection leg or half-leg. A cross-connect connects two legs together.

Note   The value of the VPIs and VCIs can change as the traffic is relayed through the ATM network.

To configure a point-to-point VCC, perform the following steps, beginning in global configuration mode:

Note   The row index for rx-cttr and tx-cttr must be configured before using this optional parameter. See "Configuring Resource Management."

Note   When configuring PVC connections, begin with lower VCI numbers. Using low VCI numbers allows more efficient use of the switch fabric resources.

Note   This parameter specifies the weight assigned to the output VC for weighted round robin scheduling and is an integer in the range of 1 to 15.This parameter is valid only on systems equipped with the switch processor feature card. (Catalyst 8540 MSR and Catalyst 8510 MSR and LightStream 1010 with FC-PFQ). For more information on scheduling, see "Scheduling Output" in the Guide to ATM Technology.

Note   The sched option is only available on OC-48c interfaces. Each OC-48c interface has four OC-12 schedulers. The sched variable is used to select the specific OC-12 scheduler for which the virtual circuit is assigned for output on an interface and is therefore a number between 1 and 4.

Examples

The following example shows how to configure the internal cross-connect PVC on Switch B between interface ATM 3/0/1 (VPI = 0, VCI = 50) and interface ATM 3/0/2 (VPI = 2, VCI = 100) (see Figure 6-1):

The following example shows how to configure the internal cross-connect PVC on Switch C between interface ATM 0/0/0, VPI = 2, VCI = 100, and interface ATM 0/0/1, VPI 50, VCI = 255:

Each subsequent VC cross-connection and link must be configured until the VC is terminated to create the entire VCC.

Note   The above examples show how to configure cross-connections using one command. This is the preferred method, but it is also possible to configure each leg separately, then connect them with the atm pvc vpi vci interface atm card/subcard/port vpi vci command. This alternative method requires more steps, but might be convenient if each leg has many additional configuration parameters or if you have configured individual legs with SNMP commands and you want to connect them with one CLI command.

Displaying VCCs

To show the VCC configuration, use the following EXEC commands:

Note   The following examples differ depending on the feature card installed on the processor.

Examples

The following example shows the Switch B PVC configuration on ATM interface 3/0/1:

The following example shows the Switch B PVC configuration on ATM interface 3/0/1:

The following example shows the Switch B PVC configuration on ATM interface 3/0/1, VPI = 0, VCI = 50, with the switch processor feature card installed:

Deleting VCCs from an Interface

This section describes how to delete a VCC configured on an interface. To delete a VCC, perform the following steps, beginning in global configuration mode:

Example

The following example shows how to delete the VCC on ATM interface 3/0/0, VPI = 20, VCI = 200:

Confirming VCC Deletion

To confirm the deletion of a VCC from an interface, use the following EXEC command before and after deleting the VCC:

Example

The following example shows how to confirm that the VCC is deleted from the interface:

Configuring Terminating PVC Connections

This section describes configuring point-to-point and point-to-multipoint terminating permanent virtual channel (PVC) connections. Terminating connections provide the connection to the ATM switch router's route processor for LAN emulation (LANE), IP over ATM, and control channels for Integrated Local Management Interface (ILMI), signalling, and Private Network-Network Interface (PNNI) plus network management.

Figure 6-2 shows an example of transit and terminating connections.

Point-to-point and point-to-multipoint are two types of terminating connections. Both terminating connections are configured using the same commands as transit connections (discussed in the previous sections). However, all switch terminating connections use interface atm0 to connect to the route processor.

Note   Since release 12.0(1a)W5(5b) of the system software, addressing the interface on the processor (CPU) has changed. The ATM interface is now called atm0, and the Ethernet interface is now called ethernet0. The old formats (atm 2/0/0 and ethernet 2/0/0) are still supported.

To configure both point-to-point and point-to-multipoint terminating PVC connections, perform the following steps, beginning in global configuration mode:

When configuring point-to-multipoint PVC connections using the atm pvc command, the root point is port A and the leaf points are port B.

Note   The row index for rx-cttr and tx-cttr must be configured before using this optional parameter. See "Configuring Resource Management."

Note   This parameter specifies the weight assigned to the output VC for weighted round robin scheduling and is an integer in the range of 1 to 15.This parameter is valid only on systems equipped with the switch processor feature card. (Catalyst 8540 MSR and Catalyst 8510 MSR and LightStream 1010 with FC-PFQ). For more information on scheduling, see "Scheduling Output" in the Guide to ATM Technology.

Note   The sched option is only available on OC-48c interfaces. Each OC-48c interface has four OC-12 schedulers. The sched variable is used to select the specific OC-12 scheduler for which the virtual circuit is assigned for output on an interface and is therefore a number between 1 and 4.

Examples

The following example shows how to configure the internal cross-connect PVC between interface ATM 3/0/1, VPI = 1, VCI = 50, and the terminating connection at the route processor interface ATM 0, VPI = 0, and VCI unspecified:

The following example shows how to configure the route processor leg of any terminating PVC:

When configuring the route processor leg of a PVC that is not a tunnel, the VPI should be configured as 0. The preferred method of VCI configuration is to select the any-vci parameter, unless a specific VCI is needed as a parameter in another command, such as map-list.

Note   If configuring a specific VCI value for the route processor leg, select a VCI value higher than 300 to prevent a conflict with an automatically assigned VCI for well-known channels if the ATM switch router reboots.

Displaying the Terminating PVC Connections

To display the terminating PVC configuration VCs on the interface, use the following EXEC command:

See Displaying VCCs for examples of the show atm vc commands.

Configuring PVP Connections

This section describes configuring a permanent virtual path (PVP) connection. Figure 6-3 shows an example of PVPs configured through the ATM switch routers.

To configure a PVP connection, perform the following steps, beginning in global configuration mode:

Note   When configuring PVP connections, begin with lower virtual path identifier (VPI) numbers. Using low VPI numbers allows more efficient use of the switch fabric resources.

Note   The row index for rx-cttr and tx-cttr must be configured before using this optional parameter. See "Configuring Resource Management."

Note   This parameter specifies the weight assigned to the output VC for weighted round robin scheduling and is an integer in the range of 1 to 15.This parameter is valid only on systems equipped with the switch processor feature card. (Catalyst 8540 MSR and Catalyst 8510 MSR and LightStream 1010 with FC-PFQ). For more information on scheduling, see "Scheduling Output" in the Guide to ATM Technology.

Note   The sched option is only available on OC-48c interfaces. Each OC-48c interface has four OC-12 schedulers. The sched variable is used to select the specific OC-12 scheduler for which the virtual circuit is assigned for output on an interface and is therefore a number between 1 and 4.

Examples

The following example shows how to configure the internal cross-connect PVP within Switch B between interfaces 4/0/0, VPI = 30, and interface ATM 1/1/1, VPI = 45:

The following example shows how to configure the internal cross-connect PVP within Switch C between interfaces 0/1/3, VPI = 45, and interface ATM 1/1/0, VPI = 50:

Each subsequent PVP cross connection and link must be configured until the VP is terminated to create the entire PVP.

Displaying PVP Configuration

To show the ATM interface configuration, use the following EXEC command:

Example

The following example shows the PVP configuration of Switch B:

The following example shows the PVP configuration of Switch B with the switch processor feature card installed:

Deleting PVPs from an Interface

This section describes how to delete a PVP configured on an interface. To delete a PVP, perform the following steps, beginning in global configuration mode: