Editing Medium Attachment Unit (section)

==Similar equipment==
The original Ethernet's successor standard, [[Fast Ethernet]], introduced<!-- at least in the current standards this is a clause 1 thing--> division into [[medium access control]] (MAC) and physical ([[PHY]]) layers connected with [[media-independent interface]] (MII). Some early Fast Ethernet hardware had physical external MII connectors, functionally similar to the AUI connector, but generally separate adaptors became obsolete. However, the tradition of using a separate low-level I/O device in networking has continued in fast [[optical fiber]] network interfaces, where the [[GBIC]], [[XENPAK]], [[XFP]], and [[enhanced small form-factor pluggable transceiver|enhanced small form-factor pluggable]] (SFP+) pluggable transceiver modules using the [[XAUI]] interface play a similar role.

The main difference between AUI and MII is that the AUI deals with line-coded signals, which is specific to the physical medium (10BASE5, 10BASE2 and 10BASE-T all use the same line code), while MII is genuinely media-independent. So while MII and AUI as external connections were similar from a user's point of view, in terms of signalling the equivalent of MII for classic Ethernet were the non-standardized interfaces between MAC and Serial Interface as found in e.g. the [[AMD_LANCE_Am7990#Related_chips|Am7990]] family.