Cabling performance parameters are not mysterious. They are symptoms that enable you to track down flaws that can distort and ruin the signal on twisted-pair cable. For example:
The signal might be getting too faint as it traverses the cable.
The copper wires in a pair might not be twisted tightly all along the cable. This prevents the positive and negative signals in a pair from balancing out and creates an electromagnetic field. This electromagnetic field induces false signals on neighboring cables and may corrupt data transmission.
Flaws in the cable structure might be causing part of the signal to be reflected back to the source, resulting in problems there.
Expressing performance ...