Information Technology Reference
In-Depth Information
zontal cable should use 24-gauge wire, but that 22-gauge wire that meets the trans-
mission requirements of the standard may also be used. It is vague about the wire
size of cross-connect wire, requiring only that the wire meet the same transmission
characteristics as regular horizontal UTP cable.
Cross-connect wire is normally used in wiring closets ,so it does not need to be
plenum rated. The normal insulation for cross-connect wire is PVC. Some local
codes may require riser or plenum rating for these locations.
Cross-Connect Wire Category
The performance categories for cross-connect wire are the same as for horizontal
cable. The proper category of wire should always be used when making your cross-
connects. This means that a Category 5e installation will require Category 5e
cross-connect wire and that lower category installations will require wire that
meets at least the specified link category. You may always use a higher category rat-
ing, as with any cable or component. For example, you may use Category 5e or 6
(or AC6, “Augmented” Category 6) wire in a Category 3 or 4 installation.
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However, the category of the installation becomes the lowest category of any
installed component (connector, cable, patch, and punchdown), so be sure to use
the correctly rated components.
Because there is no jacket to show the wire ratings, the category of installed
cross-connect wire is difficult to determine, unless it is Category 5e or higher wire.
Category 5e cross-connect wire has an extreme amount of twist to each pair, so it is
easily recognized, because there is no plastic jacket to hide the twists. Category 5e
and Category 6 are difficult to distinguish, as are Category 3 wire and Category 2
(or uncategorized wire), since the appearances may be similar. You may need to keep
track of all the cross-connect wire used in your facility. The category, if any, should
be clearly marked on the wire spool. If you are in an environment where you have
total control over all the wire and cable, you may want to use Category 5e or 6, the
highest category of cross-connect wire available, for all your cross-connects. A
higher category may always be used, and the benefit is greater “headroom” on the
performance parameters. Keep in mind, however, that the tight twists also make this
wire a little harder to terminate, particularly in 66 blocks.
There are not-too-subtle differences between category ratings from different
manufacturers. A manufacturer normally indicates that its premium cable is better
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Category 6 and AC6 cables are simply very high performance versions of Category 5e and may be
freely substituted without the 5e/6 connector compatibility issues.
