Network Router User's Manual

Configuring SVCs, PVCs, SoftPVCs, PVPs, and VPTunnels 3-9

Configuring PVCs

A PVC is a permanent logical connection that you must configure manually, from source

to destination, through the ATM network. Once configured, the ATM network maintains

the connection at all times, regardless of traffic flow. That is, the connection is always up

whether there is traffic to send or not.

Figure3-2 shows an example PVC between ATM-capable router A and router D. This

example network is used throughout this section to describe how to set up PVCs.

Figure3-2 Example Network for Configuring PVCs

When configuring a PVC, the virtual path identifiers/virtual channel identifiers

(VPIs/VCIs) must match between devices, as shown in Figure3-2 between:

• Source router A and ATM switch router B, which both use VPI=0, VCI=50

• ATM switch routers B and C, which both use VPI=2, VCI=100

• ATM switch router C and destination router D, which both use VPI=50, VCI=255

The VPI/VCIs that create an internal crossconnect within a switch can differ, as shown in:

• ATM switch router B between interfaces 3/0/1 (VPI=0, VCI=50) and 3/0/2 (VPI=2,

VCI=100)

• ATM switch router C between interfaces 0/1/1 (VPI=2, VCI=100) and 0/0/1 (VPI=50,

VCI=255)