Digital Equipment DECconcentrator 500, Installation Manual, Page: 88 / 98

Glossary–2
DAC
See Dual Attachment Concentrator.
DAS
See Dual Attachment Station.
Dual Attachment Concentrator (DAC)
A concentrator that offers two connections to the FDDI network capable of accom-
modating the FDDI dual (counter-rotating) ring and additional ports for connection
of other concentrators or FDDI stations.
Dual Attachment Station (DAS)
An FDDI device that offers two connections to the FDDI network capable of accom-
modating the FDDI dual (counter-rotating) ring.
dual ring of trees
A topology of concentrators and nodes that cascade from concentrators on a dual
ring.
entity
An active element within an Open Systems Interconnection layer or sublayer.
FDDI
See Fiber Distributed Data Interface.
FDDI connector
A category of connectors that meet the ANSI PMD standard and are used to connect
single attachment stations, dual attachment stations, and concentrators to an FDDI
network. Type A and B connectors are used to connect a concentrator to the dual ring.
Type M and S connectors are used to connect concentrators and single attachment
stations.
FDDI network
A network that meets the ANSI X3T9 standard. A counter-rotating timed-token dual
ring network operating at a bandwidth of 100 Mb/s.
fiber
Dielectric that guides light; waveguide.
Fiber Distributed Data Interface (FDDI)
A set of ANSI/ISO standards that define a high-bandwidth (100-Mb/s) general-pur-
pose local area network connection between computers and peripheral equipment in
a timed-token passing, dual ring of trees configuration.