Local Area Transport (LAT)[1][2] is a non-routable (data link layer) networking technology developed by Digital Equipment Corporation[3] to provide connection between the DECserver terminal servers and Digital's VAX and Alpha and MIPS host computers via Ethernet, giving communication between those hosts and serial devices such as video terminals and printers.
In 1984, the first implementation of the LAT protocol connected a terminal server to a VMS VAX-Cluster in Spit Brook Road, Nashua, NH.
LAT and VMS drove the initial surge of adoption of thick Ethernet by the computer industry.
Subsequently, Cisco routers, which implemented TCP-IP and DECnet, emerged as a global connection between these packet-based Ethernet LANs.
The LAT 80 millisecond delay offloads both the network by sending fewer larger packets which also reduces interrupts at each system.