The Attachment Unit Interface is a physical and logical interface defined in the IEEE 802.3 standard for 10BASE5 Ethernet and the earlier DIX standard. The physical interface consists of a 15-pin D-su
AUI Connectors. The male connector (left) is on the MAU, and the female connector (right) is on the DTE device (typically either a computer or an Ethernet hub). Note the sliding clip.
AUI Connector with numbered pins on the DEC EtherWorks LC (DE100) Ethernet controller. Note the jackposts (as opposed to a sliding clip).
A Medium Attachment Unit is a transceiver which converts signals on an Ethernet cable to and from Attachment Unit Interface signals.
Attachment Unit Interface
…the earlier DIX standard. The physical interface consists of a 15-pin D-subminiature connector that links an Ethernet node's physical signaling to the Medium Attachment Unit (MAU), sometimes referred to as a transceiver. An AUI cable can extend up to 50 metres (160 feet), though often the MAU and data terminal equipment's…
A thicknet MAU. The vampire tap is shown with a piece of yellow coaxial cable (cut off on either side of the tap) of the type used for 10BASE5 Ethernet.
A thinnet MAU, showing a single BNC and a DA15 connector
Two Medium Attachment Units (MAUs). The units shown are backwards-compatibility–oriented 10BASE-T MAUs, not older 10BASE5 or 10BASE2 MAUs.
A collection of old Ethernet equipment. At the top of the image, from left to right: A thinnet MAU with passthrough BNC connectors and a DA15 connector, a thicknet MAU with passthrough N connectors and a DA15 connector, and an AUI cable for connection of an MAU to the DA15 port.