36
16-PORT TYPE 3 MAU
5. Glossary
adapter
—the card installed in a PC that allows the PC to access the token-ring
network.
ARL
—adjusted ring length. This is the total length of the cable connecting
MAUs in a single token ring, minus the shortest inter-MAU segment.
attaching device
—each device directly connected to the token ring. Examples:
a PC, a midrange computer such as an IBM AS/400, and a front-end
processor for a mainframe computer.
backup path
—in a normal configuration, there is an unused pair of wires in
the twisted-pair cable used in the network. This extra pair of wires, used in
conjunction with a backup circuit inside the MAUs, is called the backup path.
It can be used to provide an alternate path if part of the ring is inoperative.
See
Section 3.1.2
.
category 5
—cable defined by the EIA/TIA for data applications up to 100
Mbps. See
Section 1.3.1
.
frame
—when an attaching device appends data to the network token, the
token becomes a frame.
lobe
—the cable between an MAU and an attaching device.
loopback cable
—used with RJ-45-equipped MAUs when there is only one
MAU for a ring. It connects ring in to ring out.
main ring
—the cable between the MAUs in a ring.
MAU
—Multistation Access Unit. This is the wiring concentrator in a token-
ring network.
station—
synonym for attaching device.
terminating plug
—this is used in either the Ring In or Ring Out connector on
the MAU to use the backup path. Also called a wrap plug.
token
—a unique bit sequence that is passed from station to station in
sequence on a token-ring network. Any device wanting access to the network
will append data to the token, making it a frame.