Fiber communication system maintenance depends on optical time domain reflectometers. An OTDR simply generates a pulse inside a fiber to be tested for faults or defects. Different events within the fiber create a Rayleigh back scatter. Pulses are returned to the OTDR and their strengths are then measured and calculated as a function of time and plotted as a function of fiber stretch. The strength and returned signal tell about the location and intensity of the fault present. Not only maintenance, but also optical line installation services utilize OTDRs. Additionally, nationwide telephone exchanges and poles within the network use OTDRs for smooth functioning.