1. A method for monitoring an external surface of a cable, said external surface being defined by stranding elements, the method comprising: telemetrically acquiring a profile of the external surface of the cable by means of a laser optical triangulation technique; obtaining a time-domain signal representative of the telemetrically acquired profile of the external surface of the cable; performing a spectral analysis of the time-domain signal representative of the acquired profile of the external surface of the cable to obtain a frequency spectrum having at least one characteristic spectral component each corresponding to harmonics due to cable geometry, the at least one characteristic spectral component dividing the frequency spectrum into a plurality of frequency bands, frequencies in the plurality of frequency bands not corresponding to the at least one characteristic spectral component; detecting whether the cable comprises any of multiple types of stranding defects based on spectral content in at least one of the plurality of frequency bands; and providing, in response to detecting at least one stranding defect among the multiple types of stranding defects, an indication of the at least one detected stranding defect.