By making its measurements in the frequency domain, the LANTEK 6 and LANTEK 7 can accurately measure short links. Testers that measure in the time domain with Digital Signal Processors have problems measuring short links. This is because the frequency domain is simulated by a series of electrical pulses. These frequency pulses are imperfectly formed (not a square wave). Ideally, a tester wants to read 1's or 0's. With imperfectly formed pulses, the tester may sample during the rise time (or decay time) of a pulse and improperly report a 0 as a 1, or vice-versa. Averaging of several readings will minimize this improper reporting at distances out from the Tester. But at distances close to the tester, the pulses are always caught during the rise time and even averaging cannot improve the measurement accuracy. The change to measure Permanent Link (which does not include patchcords) vs. Basic Link (which includes the patchcord) was prompted by the desire to move the near-to-the-tester point away from the tester in order to allow pulses to complete their rise time and minimize the short link problem. The buffer provided by the patchcord in Permanent Link measurements still does not eliminate measurement inaccuracy for the first few meters along a Permanent Link.