The POPPOP The POP, ‘Point of Presence’, is located at Enel’s Primary Cabins, but not exclusively; it also acts as a meet-me-room for Operators. It contains each Operator’s OLT equipment, as well as the OTDR monitoring system., ‘Point of Presence’, is located at Enel’s Primary Cabins, but not exclusively; it also acts as a meet-me-room for Operators. It contains each Operator’s OLTOLT An acronym for Optical Line Terminal. The OLT is designed to deliver data to the end customer and is used to connect fiber-optic trunk lines. It performs two essential functions: for the upstream, it completes the upstream access of the PON network; for the downstream, it sends and distributes the acquired data to all terminal devices. equipment, as well as the OTDROTDR An acronym for Optical Time Domain Reflectometer. An optoelectronic measuring device used to carry out fault analysis and diagnosis for optical fibres. monitoring system.