To say whether or not you will experience problems with a custom cable that is less than a foot in length would depend on a great number of variables. Factors that effect performance include the quality of the cable, the strength of the signal being transmitted, other local sources of interference, and the quality of the networking equipment that is controlling the signal.

One possible problem would be signal "echo". This can occour when the signal-to-noise ratio of a cable favors the noise. The crosstalk between pairs becomes harder to control in extremely short lengths of cable. Although this problem can exist in any length of cable, it becomes a much larger issue when the cables get down to around a few inches in length.

It is possible to use custom cables in short length, but use caution. Anything around 3 to 4 inches or smaller, you are risking the possibility of some noise issues. Cheap, poor quality cable is likely to start producing these type of errors at much longer lengths of cable, due to the fact that its original performance values were very low from being a inferior product to begin with.

CAT 5 Cable Company produces custom length patch cables, even sizes under one foot. Many of our customers have ordered lengths as small as 3 or 4 inches, and did not report any significant issues. We 100% test all our cables to ensure these issues will not effect you.