Source : Free On-Line Dictionary of Computing

Optical Time Domain Reflectometry
     
        Measurement of the elapsed time and intensity of light
        reflected on {optical fibre} using an optical time domain
        reflectometer.  The reflectometer can compute the distance to
        problems on the fibre such as attenuation and breaks, making
        it a useful tool in optical network trouble-shooting.
     
        (1995-02-01)