A full listing of all BACnet router functions is extensive—see the BACnet specification for complete details on routers. From a general perspective, BACnet routers are required to pass BACnet messages between different BACnet networks. This applies to all directed messages as well as broadcast messages.

Usually, a BACnet router is used to join networks of different media/link-layer types, for example a router with RS-485 MS/TP port(s) and an Ethernet-BACnet/IP port. For router examples in diagrams, see Example Internetwork Diagrams.