Hardware Reference
In-Depth Information
Unlike Fast Ethernet and standard Ethernet over UTP, Gigabit Ethernet uses all four wire
pairs. Thus, Gigabit Ethernet requires dedicated Ethernet cabling; you can't “borrow”
two wire pairs for telephone or other data signaling with Gigabit Ethernet as you can
with the slower versions. Most Gigabit Ethernet adapters can also handle 10BASE-T and
100BASE-TX Fast Ethernet traffic, enabling you to interconnect all three UTP-based
forms of Ethernet on a single network.
Gigabit Ethernet hardware was initially very expensive, thus limiting the use of Gigabit
Ethernet to high end network interconnections. More recently the prices of cables, ad-
apters and especially switches has fallen dramatically, making Gigabit the recommended
choice for all new cable, adapter, and switch installations.
Neither Fast Ethernet nor Gigabit Ethernet support the use of thin or thick coaxial
cable originally used with traditional Ethernet, although you can interconnect coaxial
cable-basedandUTP-basedEthernetnetworksbyusingmediaconvertersorspeciallyde-
signed hubs and switches.
10 Gigabit Ethernet
10 Gigabit Ethernet is a high-speed networking standard that incorporates many different
types of physical interconnections including several that are fiber optic and copper based.
Of all of the possible connection types, the only one relevant to PCs is called 10GBASE-
T, which uses standard twisted-pair cables and 8P8C (RJ45) connectors just like Fast and
Gigabit Ethernet.
10 Gigabit Ethernet (10GBASE-T) requires Category 6a (or better) cabling for support of
connection distances up to 100 meters (328 feet). Lower grade Cat 6 cable can be used if
the distance is limited to 55 meters (180 feet). Just as with Gigabit Ethernet, all four pairs
in the cable are used.
10GigabitEthernethardwareiscurrentlyveryexpensive,andlimitedtohighendnetwork
interconnections,typicallybetweenserversorasabackboneconnectionbetweenmultiple
Gigabit Ethernet networks. Once the prices of adapters and switches falls to be close to
those for Gigabit Ethernet, we will see 10 Gigabit Ethernet start to become popular for
PC-based networks. To prepare for a future upgrade to 10 Gigabit Ethernet, consider in-
stalling only Category 6a or better cabling in any new installations.
Wireless Ethernet
The most common forms of wireless networking are built around various versions of the
IEEE 802.11 wireless Ethernet standards, including IEEE 802.11b, IEEE 802.11a, IEEE
802.11g, and IEEE 802.11n.
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