Patent ID: 6995551

Claim:
A physical layer device including a first port, a second port, and a cable that has one end that communicates with the first port and an opposite end that communicates with the second port, said physical layer device comprising: a cable tester that communicates with the first and second ports and that tests the cable to determine a cable status, which includes an open status, a short status, and a normal status, wherein said cable tester includes: a pretest module that senses activity on the cable and that selectively enables testing depending upon said sensed activity; a test module that is enabled by said pretest module, transmits a test pulse on the cable, measures a reflection amplitude, calculates a cable length, and determines said cable status based on said measured amplitude and said calculated cable length; a frequency synthesizer that communicates with the cable and that selectively outputs a plurality of signals at a plurality of frequencies on the first port; and an insertion loss calculator that receives said signals on the second port and that estimates insertion loss.