The pair+N topology includes a pair of nodes that are directly connected to the following:
Shared storage.
An additional set of nodes that use the cluster interconnect to access shared storage (they have no direct connection themselves).
The following figure illustrates a pair+N topology where two of the four nodes (Node 3 and Node 4) use the cluster interconnect to access the storage. This configuration can be expanded to include additional nodes that do not have direct access to the shared storage.