Distance Measure
EIA/TIA-568A specifies maximum cable lengths for network media.
Cables that are too long can cause delays in transmission and network errors.
Cable testers use time domain reflectometry to find the distance of a cable.
Time domain reflectometry is like using radar in that a signal is sent; it bounces off an object, and is reflected back to the emitting device.
The time it takes for the signal to travel between the two points indicates the distance to the object.