Patch Panels, Cross Connects, and Patch Cords - LAN Wiring - page 202

Proper marking of the patch positions is also an important part of an instal-
lation. Generally, each wiring closet, cable termination, rack, patch, and hub is
required to have a unique identification, according to EIA/TIA 606. In the case of
patch panels, you will have to provide your own circuit or jack position identifi-
cation, separate from the panel's numbering, unless you have a very small instal-
lation and can use the jack numbers as your station numbers. The detailed
requirements for circuit identification have occurred fairly recently, and it is also
difficult to provide labeling for closely spaced jacks, so many patch panel manu-
facturers just provide a stick-on label holder that can be positioned above or
below a row of jacks.
A typical patch position might need to be marked with a wiring closet number,
patch number, cable number, and jack position number such as “W4-P10-C321-
J15.” However, the space allowed for each jack might require this to be shortened
to “C321-J15,” with the patch number marked on the panel itself and the closet
number obvious from where the panel was located. The rules for marking identifi-
cation numbers are part of an emerging standard and will get more detailed as time
goes on. Panel manufacturers will begin to incorporate more of the marking guide-
lines in their product's features. For the time being, we may have to make do with
adhesive label strips and other marking methods.
Patch Cords
A patch cord consists of a length of flexible cable, terminated at either end by an 8-
pin modular plug. The patch cord, in reality, is identical to the user cables in the
work area and the wiring closet. As a matter of fact, all of these cords go by a num-
ber of names that reflect their purpose, rather than their construction. For example,
a cord from a patch to another patch is called a patch cord , but an identical cord
from a patch to a hub is technically an equipment cord . The cord from the work-
station to the outlet connector is also an equipment cord. Equipment cords are
sometimes called user cords , because they are presumably connected by the user, not
the cable installer, to the user's equipment. Oh, yes, all of these cords are sometimes
called cables instead.
The one distinguishing feature of the patch cord is that it is usually shorter than
the user cords. We will describe the wire and connectors for these types of cables in
the next chapter. In this section, we will concentrate on the characteristics that make
a good patch cord, with the understanding that these same characteristics apply to
all user cables.