Information Technology Reference
In-Depth Information
the same data cable as the workstation computer. However, totally mixing voice and
data in this manner is potentially problematic. Some voice experts recommend totally
separate physical networks, including cabling, for VoIP networks. If you have any
doubts about the basis for this approach, consider first how often your computer net-
work goes down, and then try to remember the last time the phones failed.
The three keys to a successful structured LAN wiring installation are
proper design
,
quality materials
, and
good workmanship
. Proper design involves the careful
orchestration of several complex factors, applied in a standard fashion, to produce
a successful installation plan that will meet your needs for today and for many years
to come. These factors include the length of run, wire type, wire terminations, and
routing. Many of the technical details are covered in other areas of this topic. Here,
we will give you an overview of how these factors come into play in creating a suc-
cessful design.
In creating your cabling design, you will have to make many decisions. Most
of these decisions can be reduced to a few simple rules, so that your overall perform-
ance requirements actually dictate the proper components to choose. In this way,
you will ensure that the final wiring system design will provide the connectivity, per-
formance, and growth that you need.
This section gives a brief explanation of structured cabling concepts with a
summary of some of the design considerations involved and culminates in a simple
design example. In later chapters, we will explain many of the common wire types
and wiring systems that are, or have been, used in LAN wiring. Although some of
the older cabling methods are no longer being used in new installations, it is impor-
tant that they be here for completeness and for those who must add to or modify
older cabling systems. For the most part, we will talk about unshielded twisted-pair
wiring when citing design factors and installation techniques. This has been the area
of heated activity in the specification of wire, installation and performance stan-
dards, and introduction of new technologies. This is clearly where the action is.
Fiber-optic cabling is also a current technology, but its use in the workplace is
limited at present. It is more expensive to buy, more difficult and expensive to
install, requires more expensive workstation and hub interfaces, and generally
exceeds the bandwidth required for the current and next generation of LAN data
throughput. Fiber-optic cabling does, however, have several unique and very bene-
ficial characteristics that can be of great assistance in larger cabling designs. For that
reason, a description of fiber-optic cabling is included wherever that medium is par-
ticularly useful.
