BACnet/SC uses a hub-and-spoke topology. The central Hub Function performs message forwarding for all broadcast messages and for point-to-point messages for devices that do not support more efficient direct connections. All Metasys devices support direct connections.
The following figure illustrates the normal scenario of the BACnet/SC network, where every node
is connected to the Primary Hub.
Figure 1. Normal BACnet/SC network scenario
The following figure illustrates the failover scenario of the BACnet/SC network, where
the Primary Hub is offline and nodes get re-routed to the Failover Hub.
Figure 2. Failover BACnet/SC network scenario
For more information about the BACnet/SC topology and BACnet/SC more generally, refer to BACnet/SC Workflow Technical Bulletin (LIT-12013959) .