November 30th, 2008 
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Tags: Wiremap failures are the easiest to locate as they involve opens, shorts, and pairing faults. Use wiremap test results and length measurements to isolate the location of termination, continuity, and pairing faults. Some split pair faults may require a distance-to-crosstalk test (such as TDX) which operates in a manner similar to a distance-to-fault test (length or TDR), and is described in the Advanced Cable Diagnostics section.
Most wiremap failures occur at cable terminations, either at the RJ45 (plug or jack), or at an intermediate cross connect or patch panel. Faults at the RJ45 can usually be seen by checking the wire colors carefully against T568A or T568B pin out colors, or by checking the RJ45 plug for wires that did not seat fully to the end of the connector when it was crimped. While checking for wires that were not fully seated, also try check to see if the correct type of RJ45 was used (stranded or solid wire pins) – though that is difficult once crimped (see the figure below)
Pin styles for crimping stranded and solid cable in an RJ45 plug
Using the wrong style of pin may cause intermittent connections after a period of time, though the cable usually works immediately after it is made
Are the cables too neatly “dressed?†If tie-wraps are too tight, or if high performance cable (Category 6/ISO Class E, and especially Category 6A/ISO Class EA) is aligned perfectly in parallel for too great of a distance it may create problems which otherwise would not exist.
