Information Technology Reference
In-Depth Information
Cables and cable ratings are covered in more detail in Chapter 5, “Wire and
Cable Technology for LANs,” and Appendix E, “LAN Wiring Standards.” The TR
(wiring closet) is the gathering point for all of the home-run cables that serve work-
stations of a particular floor or area in your building. The size and location of
wiring closets are actually specified in standards, such as TIA/EIA-569-A. This stan-
dard refers to several types of wiring closets, such as the TR, the IC, and the MC.
Such a variety of wiring closets is appropriate for telephone wiring, since it is
much more extensible than LAN cabling. However, since the topic of this topic is
restricted to LAN wiring, we will simplify this to just “telecommunications room.” For
our purposes, then, all wiring outward from the patch or other station wire termina-
tion point to the workstation outlet jack will be considered simply horizontal cabling
and will conform to those standard practices that are appropriate for LAN wiring.
As mentioned previously, horizontal cabling includes the wire terminations in
the TR. You will typically bring all the individual station cables into the wiring
closet at the same entry point, then down a wall onto a wiring board. Wiring boards
are often large 4-by-8 ft sheets of 3/4-in plywood, mounted securely to a wall of the
TR, and painted an appropriate color. Of course, TIA/EIA-569-A has a color code
FIGURE 1.7
Punchdowns.
