Hardware Reference
In-Depth Information
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.
10 Gigabit Ethernet hardware is currently very expensive, and limited to high-end network
interconnections, typically between servers or as a backbone connection between multiple 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 installing 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.
Wireless Fidelity (Wi-Fi) is a logo and term given to any IEEE 802.11 wireless network product
certified to conform to specific interoperability standards. Wi-Fi certification comes from the Wi-Fi
Alliance, a nonprofit international trade organization that tests 802.11-based wireless equipment to
ensure it meets the Wi-Fi standard. To carry the Wi-Fi logo, an 802.11 networking product must pass
specific compatibility and performance tests, which ensure that the product will work with all other
manufacturers' Wi-Fi equipment on the market. This certification arose from the fact that certain
ambiguities in the 802.11 standards allowed for potential problems with interoperability between
devices. By purchasing only devices bearing the Wi-Fi logo, you ensure that they will work together
and not fall into loopholes in the standards.
Note
The Bluetooth standard for short-range wireless networking, covered later in this chapter, is
designed to complement, rather than rival, IEEE 802.11-based wireless networks.
The widespread popularity of IEEE 802.11-based wireless networks has led to the abandonment of
other types of wireless networking such as the now-defunct HomeRF.
Note
Although products that are certified and bear the Wi-Fi logo for a particular standard are
designed and tested to work together, many vendors of wireless networking equipment created
devices that also featured proprietary “speed booster” technologies to raise the speed of the
wireless network even further. This was especially common in early 802.11g devices, while
newer devices conform more strictly to the official standards. Although these proprietary
solutions can work, beware that most, if not all, of these vendor-specific solutions are not
interoperable with devices from other vendors. When different vendor-specific devices are
mixed on a single network, they use the slower common standard to communicate with each
other.
