When you install fiber-optic cable enclosed by PVC innerduct through walls or floors, you must ensure that the penetrations, or holes, meet the American Society of Test and Measurement E814 standards of two-hour "F" and "T" ratings. FO-VC2 JOINT USE - VERICAL MIDSPAN CLEARANCES 48. (FOA) was founded in 1995 to help develop the workforce to build the fiber optic networks to support a rapid expansion in communications and the Internet. The charter of the FOA was to promote professionalism in fiber optics through education, certification, and. Recommendations for Fiber Optic Cable Installation Where reels are supplied with protective material fitted over the cable, the protection should remain in place until the cable will be installed. During installation, all curvatures should be smooth. Fibre can either be single-mode (SM) or multimode (MM).