A method for connecting user devices (130) to optical fiber units (210) contained in an optical cable (110), the method comprising the phases of: providing an opening (330) in a sheath (205) of the optical cable to access the optical fiber units contained in the optical cable; extracting a segment of at least one optical fiber unit from the optical cable through the opening; inserting a free end of the extracted segment of optical fiber unit into a protection tube (335); making the protection tube slide on the extracted segment of optical fiber unit to insert an end portion (350) of the protection tube, distal from the free end of the extract segment of the optical fiber unit, into the optical cable through said opening; positioning a closure element (405) on the optical cable in correspondence of the opening so as to substantially realize a closure thereof; securing in removable way the closure element (425) to the optical cable and bringing the free end of the extracted segment of optical fiber unit in correspondence of a connection point of a user device.