Define NEXT in copper cabling testing.

• A. Far-End Crosstalk; measured at the receiving end
• B. Near-End Crosstalk; measured at the transmitting end
• C. Near-End Crosstalk; measured at the receiving end
• D. Crosstalk not measured

Answer: (B)

NEXT refers to the amount of signal that leaks from an adjacent pair into another pair at the near end of the cable where the transmitter is located. It is measured at the transmitting end, comparing the unwanted crosstalk on the victim pair to the intended signal on the aggressor pair, typically expressed in dB. This near-end measurement captures how much interference is seen right where the signal is generated, which is the most critical for maintaining clean transmission. Crosstalk from the near end is different from far-end crosstalk, which would be observed at the far end, and is a separate metric.