A Note on Feeder Shelves

It is very common among service providers to attach feeder nodes to PNNI switching nodes as aggregators or concentrators. The link in the PNNI routing node going to the feeder node terminates SPVC calls. The feeder concentrates IP, Frame Relay, and ATM users and terminates PVCs on its uplink. This scenario is shown in Figure 10-8.

Figure 10-8. Feeder Nodes Attached to a PNNI Network

In order to configure this scenario, you must configure as none the PnPort signaling in the link from the PNNI routing node to the feeder shelf. This means that no signaling is running in that link and that only PVCs and SPVCs are supported.

You add the feeder from the controlled switch using the command addshelf from a BPX-8600 or the command addfdr from an AXSM card in an MGX-8850. LMI runs between the controlled switch and the feeder node. In addition, you need to set the parameter cntlvc in the cnfpnportsig command to ip so that VPI/VCI = 3/8 is created and the feeder can be managed.

Another special case as far as PnPort signaling configuration appears when VISM cards exist in a PNNI node. In that case, the PnPort signaling is configured to self. This allows the VISM card to set up voice SVCs.