cabling / shielding / so called frequency response is all about RF transmission efficiency. An efficient cable is one with 100% efficiency and 0% loss or reflection.
Wiring, after all, is an antenna, and if there's a mismatch in the impedence,
you get a 'reflected standing wave', which reduces the signal being received.
In the real world, there's always some reflection and signal loss.
A twisted cable pair (CAT 5) is better than untwisted.
Shielded cable (ie braided shielding around a twisted pair is better still.
Cat 5e and Cat 6 are top of the line.
btw: ethernet max cable length between any two NICs is 100m (328ft)