Information Technology Reference
In-Depth Information
at advanced frequencies and data rates, we have been able to further refine the
cabling components. These refinements have added orders of magnitude to our
LAN capabilities. The norm in network copper cabling is now Category 5e, which
has all but replaced Category 5 in the marketplace. However, the Category 6 speci-
fications are out, with their operation to over 200 MHz and superior performance
at the lower frequencies, and many are already specifying Category 6 as a minimum.
Category 7, with operation to 600 MHz, is close behind, with some manufacturers
already offering components that meet the presumed parameters of this technology.
Copper cabling is capable of 1 Gbps operation at lowly Category 5e, with its 100
MHz bandwidth. Imagine what you can do with 600 MHz cable!
In the fiber arena, multimode 62.5/125 µm fiber is now in wide use. However,
the high-bandwidth needs of gigabit operation have revealed concerns with run-of-
the-mill fiber, and new formulations now abound to better support gigabit speeds at
reasonable distances. In addition, new 50/125 µm multimode fiber constructions are
now standardized, and many applications lend themselves to single-mode fiber. An
entire catalog of new fiber connector types is available to better support our modu-
lar world. Although the fiber and connector types are not given the convenience of
the copper world's categories, there is nevertheless a myriad of options, with com-
mensurate capabilities.
Certified training in appropriate technology is a mandatory requirement for
the network cable technician of today. The practical knowledge has become so
detailed and the installation practices have become so crucial that every person
involved in the LAN wiring process must possess specialized education and experi-
ence, as well as the corresponding credentials. In addition, every link in every LAN
wiring system must be rigorously tested to the proper performance specifications,
whether copper or fiber (or even wireless). Wiring has progressed from “anything
goes as long as the pattern is right” to “it works only if the components and instal-
lation techniques are perfect.” Those of us who are involved in LAN wiring provide
the superhighways over which the high-speed traffic of the network now ride, and
a wild ride it is indeed. Over the past decade, we have seen routine network speeds
move from a mere 10 Mbps all the way up to 1 Gbps—100 times the speed. And
now, speeds have been extended to 10 Gbps—1000 times the first commonly used
Ethernet speed.
What will occur over the next decade? More of the same, no doubt! Modern
networks often lag at 100 Mbps (remember when the same was true of 10 Mbps?).
As always, there are some who rapidly push their networks to the next level, and
some who wait until network sluggishness or a major move pushes
them
to the next
level. With structured networks, as with expressways, traffic moves faster if net-
work capacity is increased at the center of the network. In a typical structured net-
