Overview of Networking
2-10
The Classification of Networks
Attachment Unit Interface (AUI)
Attachment Unit Interface cable (referred to hereafter as AUI cable, but which
may also be called office transceiver cable or standard transceiver cable in other
publications) is a shielded, multistranded cable that is used to connect Ethernet
network devices to Ethernet transceivers. AUI cable should be used for no other
purpose.
AUI cable is made up of four individually shielded pairs of wire surrounded by
an overall cable shielding sheath. The gauge of the internal cables determines the
thickness and relative flexibility of the AUI cable. Heavy-gauge AUI cable
(containing pairs of wire of 20 or 22 AWG wire) is capable of reaching a maximum
distance of 50 meters (164 ft.) between transceivers and the network device, but is
thick, and somewhat inflexible. The lighter-gauge AUI cable (consisting of 28
AWG wire) is thinner and much more flexible, but can only be run to a maximum
distance of 16.5 meters (54.1 ft.).
Unshielded Twisted Pair (UTP)
Unshielded Twisted Pair cabling (referred to here as UTP, but also may be termed
copper wire, 10BASE-T wire, Category 3, 4, or 5 Ethernet wire, telephone cable, or
twisted pair without shielded or unshielded qualifier) is commonly made up of
two or, ideally, four pairs of 22, 24 or 26 AWG unshielded copper solid or stranded
wires. These pairs of wires are twisted together throughout the length of the
cable. The twisting of associated pairs helps to reduce the interference of the other
strands of wire throughout the cable. UTP cable used in network installations is
the same type of cable used in the installation of telephone lines within buildings.
Figure 2-4. UTP Pair Association
As UTP cabling already exists in many facilities, and as it is inexpensive, available
in bulk and easy to install, the use of twisted pair cabling is often a significant
savings over the use of other media in a networking installation. As UTP cabling
is an accepted media in all common network technologies, it is considered a
somewhat ‘future-proof’ media. In opposition to a length of thin coaxial cable,
which can only be used for Ethernet communications between devices, UTP
cabling could initially be used for Ethernet, then be used to support Token Ring
and FDDI network equipment as the network grew.
Tx+
Tx-
Rx-
Rx+
1706n04
Summary of Contents for MMAC-5FNB
Page 1: ...Cabletron Systems Networking Guide MMAC FNB Solutions ...
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Page 10: ...viii ...
Page 188: ...Expansion Ethernet 8 12 Port Assignment and Virtual LANs ...
Page 194: ...Expansion Token Ring 9 6 Port Assignment ...