PVCs on the RPM
In general, a PVC is a static connection between two interfaces on an ATM switch or between two ports on separate switches. A PVC requires an administrative action to establish, typically by a network administrator using a CLI or network management tool. As soon as a PVC is in place, it remains in place unless specifically removed by management action. The switch ports, or the set of resources on the ports that have been allocated to the connection, also remain dedicated for the lifetime of the PVC.
Strictly speaking, a PVC is a static connection in the network. In other words, the connection does not change, regardless of network events or changes. To confuse matters, many Frame Relay and ATM networks use the term PVC to refer to a dynamically routed virtual circuit. The BPX is an example of such a network. On the RPM, two configured elements comprise a PVC: the PVC and the ATM connection. The PVC is associated with a subinterface and is assigned a local identifier, VPI, and VCI. The PVC is often associated with an IP address for Layer 3 routing purposes. An ATM connection links the PVC to a destination endpoint such as another RPM, the PXM1 trunk, or any Frame Relay or ATM port on the MGX switch.
Figure 22-19 shows PVCs and ATM connections on the RPM.
Figure 22-19 PVCs and ATM Connections
RPM connections can terminate on PXM1, FRSM, or AUSM cards, as shown in Figure 22-20.
Figure 22-20 Terminating RPM Connections
Similar to other MGX service modules, ATM connections on the RPM are either master or slave segments. A local connection has a slave connection at one end and a master connection on the other. A feeder connection has a master connection to the PXM1 trunk, a routing connection through the ATM backbone network, and a master connection on the remote MGX switch.