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Glossary, Lossary – 3Com 2226 PLUS User Manual

Page 83

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LOSSARY

10BASE-T

The IEEE specification for 10 Mbps Ethernet over
Category 3, 4 or 5 twisted pair cable.

100BASE-TX

The IEEE specification for 100 Mbps Fast Ethernet over
Category 5 twisted-pair cable.

1000BASE-LX

IEEE 802.3z specification for Gigabit Ethernet over 9/125
micron core single-mode fiber cable.

1000BASE-SX

IEEE 802.3z specification for Gigabit Ethernet over two
strands of 50/125 or 62.5/125 micron core multimode
fiber cable.

1000BASE-T

IEEE 802.3ab specification for Gigabit Ethernet over
100-ohm Category 5, 5e or 6 twisted-pair cable (using all
four wire pairs).

Auto-negotiation

Auto-negotiation is where two devices sharing a link,
automatically configure to use the best common speed.
The order of preference (best first) is: 1000BASE-T full
duplex, 100BASE-TX full duplex, 100BASE-TX half
duplex, 10BASE-T full duplex, and 10BASE-T half duplex.
Auto-negotiation is defined in the IEEE 802.3 standard
for Ethernet and is an operation that takes place in a
few milliseconds. Auto-negotiation must be enabled for
the 1000BASE-T ports to operate at 1000 Mbps, full
duplex.

Bandwidth

The information capacity, measured in bits per second,
that a channel can transmit. The bandwidth of Ethernet
is 10 Mbps, the bandwidth of Fast Ethernet is 100
Mbps and Gigabit Ethernet is 1000 Mbps.

BPDU

Bridge Protocol Data Unit. A type of information packet
that ensures that data is efficiently exchanged between
Switches in a LAN. BPDU messages detect loops in a
network, and remove them by shutting down the bridge
causing the loop.