Media access unit
(also MAU, medium access unit, multistation access unit, MSAU, Ethernet transceiver)
A media access unit (MAU) is a standalone device that acts as an Ethernet transceiver when connecting network nodes in local area networks LAN). MAUs are used in token ring network topology, where network stations form a logical ring — that is, data passes from one device to another in a continuous circle.
How MAUs work
MAUs typically operate at the data link layer (also called layer 2) of the open systems interconnection (OSI) model. MAUs manage physical connections between network devices, ensuring that data is transmitted and received correctly.
Unlike in conventional ring topology, if one device on the token ring fails, MAUs can bypass it and forward the data to the next device in the ring.
Types of MAU
- Passive: Passive MAUs operate without an external power source, which means they can extend the network in places without convenient power outlets. Passive MAUs rely on the physical properties of cables and network interface cards (NICs) for data transmission.
- Active: Active MAUs require an external power source for operation. In addition to data transmission, active MAUs can provide other network services, like amplifying signals or managing collisions.