ISO/IEC 8802-5 : 1998/Amd. 1 : 1998(E)
ANSI/IEEE Std 802.5r and 802.5j, 1998 Edition LOCAL AND METROPOLITAN AREA NETWORKS:
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Copyright © 1998 IEEE. All rights reserved.
1.3.7 C-Port: A concentrator port in a dedicated token ring concentrator.
1.3.8 data transfer unit (DTU): The entity in the dedicated token ring (DTR) concentrator that provides
frame forwarding between C-Ports and the data transfer service (if there is one).
1.3.9 dedicated token ring (DTR): Token ring architecture according to clauses 3, 9, and 10. Provides
shared bandwidth to multiple node count classic token rings or single classic stations, and enhanced full-
duplex dedicated bandwidth to single stations attached to a DTR concentrator.
1.3.10 dedicated token ring (DTR) concentrator: A concentrator with C-Ports that provide shared and
dedicated connectivity domains to attaching stations.
1.3.11 dedicated token ring (DTR) Station: A Station that supports the token passing protocol (TKP) and
transmit immediate protocol (TXI) access protocols specified in clauses 3, 4, 9, and 10. Note: Within this
document, “Station” when capitalized is used to indicate that the entity may be either a data station, or a C-
Port in Station Emulation mode.
1.3.12 fibre: A filament-shaped optical waveguide made of dielectric materials.
1.3.13 fibre optic cable: A cable containing one or more optical fibres compatible with specifications in
13.7.2.5.
1.3.14 fibre optic channel: The data path from any transmitting station’s fibre optic medium interface
connection (FMIC) or transmitting concentrator’s FMIC to the next receiving FMIC.
13.15 fibre optic interface (FOI): The interface between a station’s physical (PHY) layer and the optical
medium. It is bounded on one side by the medium interface connector (MIC) or PHY layer I/O interface,
and on the other by the fibre optic medium interface connection (FMIC).
1.3.16 fibre optic medium interface connection (FMIC): The mechanical and optical interface between
the station or fibre optic interface and the fibre optic cable. This is a duplex optical port at which confor-
mance testing is performed.
13.17 fibre optic station (FODTE): A compliant token ring station with a fibre optic interface (FOI) as
described in this standard.
1.3.18 fibre optic trunk coupling unit (FOTCU): A physical device that enables a fibre optic station to
connect to a trunk cable. The FOTCU contains the means for inserting the fibre optic station into the ring,
or conversely, bypassing the fibre optic station. Syn: fibre optic concentrator lobe port.
1.3.19 full-duplex operation: Use of the transmit immediate protocol (TXI) access protocol where
data transfer between a dedicated token ring (DTR) Station and C-Port may occur simultaneously and
bidirectionally.
1.3.20 insert: The fibre optic station transmit signals will be routed to the next downstream station in the
ring, and input signals will be routed from the next upstream station in the ring.
13.21 insertion: A signaling pattern sent by a fibre optic station to request to join the ring (INSERT). This
pattern consists of an alternating pattern of normal data signals and low light-level signals. See 13.7.2.2.
1.3.22 insertion key echo: The return of the insertion key to the station by the fibre optic trunk coupling
unit (FOTCU). See 13.7.2.2.
1.3.23 lobe: A set of transmission elements in the data path between a station’s transmitter and its own
receiver when the station is in the Bypass state.