• Fiber optic cables commonly come in multiples of 2 fiber increments, such as 6, 12, 24, 48, 72 and 144 fiber configurations. • Design engineers reserve spare fibers for potential breaks and future upgrades to the system. • Anticipating future growth during cable . This guide walks you through the simple decision steps engineers use, the common strand counts on the market, and clear rules-of-thumb for different project types so you choose a cable that fits both today's needs and tomorrow's growth. Begin by listing what the network must support now and in five. The Fiber Optic Association, Inc. The charter of the FOA was to promote professionalism in fiber optics through education, certification, and. • Fiber optic cables are often custom cut to match required lengths for each cable run, or you can order a reel matching your total length and cut segments yourself. This article. How many fibers do you need in your cable? What length does the cable need to be? What connectors do you need? How long do the breakout legs need to be? Do you need a pulling eye? What Type of Fiber Do You Need? The first question our team will ask is whether you need singlemode or multimode fiber.