The present document defines the functional and technical characteristics applicable to the Optical External Network Testing Interface (ENTI) terminated with Singlemode fibre which provides testing capability at the demarcation point between the line of the FTTH operator's network and the customer's cabling inside the house. The present document describes optical ENTI for new homes. An optical ENTI is positioned in a distribution space. It is connected to an ONT by an optical terminated cord. The home cabling is not considered in the present document. The present document specifies the functional characteristics and performance requirements for the optical ENTI within the subscriber premises and for the needs of the FTTH optical access network.