Allied Telesis AT-MR420T, Installation Manual

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Appendix B
Glossary
10Base2—Also called thin Ethernet, thinnet or CheaperNet, a 10 MHz
baseband specification. Cable impedance is 50
Ω
and maximum coaxial
segment length is 185 meters (606 ft.).
10Base5—Also called thick Ethernet, a 10 MHz baseband specification. Cable
impedance is 50
Ω
and maximum coaxial segment is 500 meters (1,640 ft.). The
cable is commonly referred to as yellow cable. Thick Ethernet cable is typically
used as a trunk or backbone path of the network.
10Base-T—IEEE 802.3 STP/UTP Ethernet. Low-cost Level 3 or better STP/
UTP wiring affords 100 meters (328 ft.) of point-to-point link segments. STP/
UTP uses RJ45 connectors and sometimes 50-pin Telco connectors to a patch
panel and runs at 10 MHz.
ATTACHMENT UNIT INTERFACE (AUI)—Connection between a MAU
(transceiver) and a DTE (typically a workstation). Includes a 15-pin D-sub
connector and sometimes a 15-conductor twisted pair cable. Maximum length
is 50 meters (164 ft.).
BASEBAND COAXIAL SYSTEM—A system whereby information is directly
encoded and impressed on the coaxial transmission medium. At any point on
the medium, only one information signal at a time can be present without
disruption.
BAYONET NUT COUPLE (BNC) CONNECTOR—A 10Base2 thin coax
connector with push-on BNC locking lug that quickly locks into place with a
half twist.
BIT RATE (BR)—The rate of data throughput on the medium in bits per
second. Ethernet specifies 10 million bits per second.
BIT TIME—The duration of one bit symbol (1/BR). Ethernet specifies a bit
time of 100 ns.
CARRIER SENSE—In a LAN, an ongoing activity of a data station to detect
whether another station is transmitting.
CARRIER SENSE MULTIPLE ACCESS with COLLISION DETECT
(CSMA/CD)—This is the access method employed by IEEE 802.3 LAN
transceivers, by which multiple stations compete for use of the transmission
MRx20T(UTP)Ver6_Book Page 31 Thursday, April 3, 1997 5:18 PM