Attachment Unit Interface

Interface for connecting an external Ethernet transceiver.
Data from the transceiver is provided at a 15-pin D-SUB connector, separated into send, receive and collision information. The end device is connected via an 8-core Twisted Pair cable, max. 50 m in length.
In the past, AUI interfaces were mainly used to connect end devices to 10Base5 transceivers (Yellow Cable/Thick Ethernet), but these days they are more normally used to connect fibre-optic transceivers.