If you are using ethernet to connect to a DAC, I recommend that your communicate with the manufacturer. For example, DCS recommends an Unshielded CAT 5 cable rather than a potentially more expensive and in particular shielded cable. In fact, they recommend AGAINST a CAT 6, 7 or 8 shielded cable. They explained to me that the reason is the design of their circuit-- what they do with the incoming signal (voltage).