99% of the CAT5/5E and 6 on the market is UTP (Unshielded Twisted Pair.) The only shielding you get is the plastic outer sheath.Cat 5 cable does go bad and some of it is very poorly shielded even when new. My experience is that Black Box shielded Cat 5 cable gives the best results in terms of noise shielding. It's not cheap but it will do the job. I have my scanner sitting right next to my router with no interference problems.