Information Technology Reference
In-Depth Information
UTP Patch Cords
Now that we have all that terminology out of the way, what makes a good UTP
patch cord? As we mentioned, a patch cord should be flexible, which means it
should use stranded wire with a flexible plastic jacket.
Patch cords usually consist of four pairs of 24-AWG, 100-ohm, stranded cop-
per, thermoplastic-insulated wires with an overall thermoplastic jacket. As with hor-
izontal cable, 22-gauge wire is allowed, but rarely used. The plastic insulation is
often PVC or a compound with similar characteristics. The cords are used in a work
area, not a plenum space, and usually do not require the stiffer plastic insulations
that are plenum-rated. An example of a typical patch cord is shown in Fig. 8.8.
Patch cord cable may have any wire colors, but the colors of the standard 4-
pair color code are normally used. TIA-568-C also offers an alternative color code,
consisting of eight unique solid colors. Actually, the color code is only important if
you make up your own patch cords from bulk cable. The colors will help you get
the wires in the correct pin positions before you crimp on the modular plug.
Patch cords have their own set of performance characteristics that are slightly
different from those for the horizontal cabling. Most of the transmission require-
ments are the same, but an additional 20% increase
2
in attenuation is allowed for
FIGURE 8.8
Typical Category 6 patch cord. (courtesy The Siemon Company.)
2
ISO/IEC 11801 allows a 50 percent attenuation increase on stranded cords, which results in some
parametric differences in the acceptable links.
