The present disclosure provides a method and system for configuring an optical time domain reflectometer (OTDR) in a gigabit passive optical networks (PON), characterized by the steps of: collecting network data of the network to be scanned by switch controller to characterize said network; collecting data from various optical network terminals (ONTs) of the gigabit passive optical networks (GPON) by an OTDR and the Switch Controller to form a training database, the training data is used to train the method; optimizing the parameters of the optical time domain reflectometer (OTDR) based on the network data and the training database by a processor provided on the switching controller using machine learning. For point-to-multipoint (PMP) networks such as PON, the present method and system provides optimal set of parameters to configure OTDR before performing trace.