IBM 8285 Nways, Installation And User Manual

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Ÿ The total Reserved Bandwidth of the Base Unit and Expansion Unit (for class-A PVC and NNI
ports, for example) cannot exceed 180Mbps.
Ÿ According to ATM Forum recommendations, PVCs cannot cross NNI links. To set up a PVC across
an NNI link, see the workaround described in “PVCs Between clusters” on page 42.
Ÿ Multicast VCCs are supported on NNI links, with VPIs in the range:
– 0-7 over 25.6Mbps ports
– 0-15 over all other ports
See also “General Guidelines for Configuring Trunks” on page 44 for further information.
Adjacent Clusters: Due to the lack of dynamic routing on NNI links, all clusters within the same
subnetwork must be adjacent, as shown in Figure 18.
Figure 18. Connections Within a Subnetwork or Campus Network (NNI)
Parallel NNI Trunk Links: Parallel NNI trunk links may also be defined between clusters for increased
availability or throughput, as shown in Figure 16 on page 35.
Parallel NNI links must begin from the same switch and end at the same switch.
Chapter 3. Building an ATM Campus Network
37