Devices that use BACnet as their "native language" can be interconnected using BACnet routers, even though they are on different kinds of local area networks (LANs). These routers are typically implemented in dedicated computers with network interface cards for different LAN types. As a practical matter, they are thus limited to use within a single building or group of buildings on a single site. In order to communicate over greater distances, it made sense to figure out how to make use of IP, the routing protocol on which both corporate "intranets" as well as the global "Internet" are based. Although not shown above, legacy devices that do not use BACnet can sometimes be integrated with BACnet networks using "gateways" or protocol "translators."