Technical comparison of SC/APC and SC/UPC connectors including endface geometry, insertion loss, return loss, color coding, applications and selection criteria. A detailed introduction to mainstream connector types like LC, SC, FC, ST, and MPO/MTP is also provided. This aims to offer a professional selection guide for. Here is a mistake that happens in fiber installations more often than anyone in the industry likes to admit: a technician installs a brand-new SC/APC connector from the fiber distribution network and connects it to a patch panel port terminated with SC/UPC. The connector clicks in, the fiber link. Selecting the right fiber optic connector in accordance with current IEC standards is crucial to the performance, reliability and future-proofing of a fiber optic infrastructure. International IEC standards define precise specifications for various fiber optic connector types, which serve as the. While the small size of fibre optic connectors does not mean they play a minor role, the type of connector you use affects the overall efficiency of light transmission across the fibre network. Their differences affect return loss, back reflection stability, and suitability for access, ODN, and high-precision applications. For example, they can be plugged into receptables on front.