AT-TS90TR 10Base-T Switch With 100Base-T Access
33
CROSS-OVER—Wiring is used when connecting a 10BASE-T MAU to
another 10BASE-T MAU or a 10BASE-T hub to another 10BASE-T hub.
For example, one 10BASE-T MAU would have the TD pair on the same
pins as another 10BASE-T MAU. If pins were wired straight, there would
be two transmitters on one pair with no receiver. Therefore, the cross-over
cable crosses the TD pair with the RD pair of UTP cable connecting the
TD pins on one end to the RD pins at the other end.
D-SUB CONNECTOR—The AUI cable uses 15-pin D-sub connectors. “D”
refers to the shape of the connector shell. Also called miniature D, DB15,
or DIX connectors.
DATA COMMUNICATION EQUIPMENT (DCE)—In RS232
specification a module, such as a modem, for connecting a DTE to other
equipment. A repeater connected to a terminal or workstation for OMEGA
LOCAL management use is wired as a DCE.
DATA TERMINAL EQUIPMENT (DTE)—In RS232 specification a
module typically at the end of a segment. The DTE could be an Ethernet
workstation, repeater or bridge.
DEPARTMENT CONCENTRATOR—Hub which provides a large
number of workstation connections. The term, department concentrator,
refers to multiple repeaters housed in an AT-36C8 chassis. See Hub/
Repeater, Repeater.
DIX CONNECTOR—See D-Sub Connector
FOIRL — A fiber optic standard that allows up to 1,000 meters (3,280 ft.)
of multimode duplex fiber optic cable in a point-to-point link.
HARMONICA ADAPTER—This adapter provides a simple way to
convert the 50-pin Telco connection to RJ45 connections.
HEARTBEAT—See SQE
HOT SWAPPING— The process of replacing a hub module without
bringing down the network. This process occurs by sliding an active
module into a fully powered up concentrator, replacing a failed module.
HOUSE WIRING—House wiring is the existing wiring inside a building.
This wiring generally originates from one or more wiring closets such as a
telephone room. Some older buildings may have wiring unsuitable for 10
megabit data rates. In these circumstances, it is recommended that the
wiring is tested with a 10BASE-T signal/wire tester.
HUB/REPEATER—A hub is a central signal distributor. It is used in a
wiring topology consisting of several point-to-point segments originating
from a central point. The term hub is often used interchangeably with the
term repeater. Multiport 10BASE-T, 10BASE2 and fiber optic (10BASE-
FL, FOIRL) repeaters are considered hubs. See Repeater.
HUB-to-HUB WIRING—See MAU-to-MAU Wiring
HUB-to-MAU WIRING—UTP cables for 10BASE-T hub-to-MAU or NIC
cards are wired straight-through. An RJ45 receptacle at the hub would
wire pin-to-pin to the RJ45 receptacle at the MAU.
