Recommendation ITU-T K.44 seeks to establish fundamental test methods and criteria for the resistibility of telecommunication equipment to overvoltages and overcurrents. Overvoltages or overcurrents covered by this Recommendation include surges due to lightning on or near the line plant, short-term induction of alternating voltages from adjacent electric power lines or electrified railway systems, earth potential rise due to power faults and direct contacts between telecommunication lines and power lines. Major changes compared with the 2017 version of this Recommendation include: - addition of nine new definitions and modifying one old definition; - clarification of main body text ; - added external Ethernet port power cross test; - revision of the test schematics to improve clarity; - introduced Intra-system ports and an Ethernet intermediate test level; - adding tolerances for 1.2/50 waveform generation; - test exemptions for certain cable lengths.