This cable consists of color-coded pairs of insulated copper wires. Every two wires are twisted around each other to form pair. Solid colors are blue, brown, green, and orange. Fiber-optic communication is a form of optical communication for transmitting information from one place to another by sending pulses of infrared or visible light through an optical fiber. Fiber is preferred. The number of optical cores in an optical fiber is the total number of equipment interfaces multiplied by 2, plus 10% to 20% of the spare quantity, and if the communication mode of the equipment has serial communication and equipment multiplexing, you can reduce the number of cores. The number of. Fiber optic transmission systems are superior to metallic conductor-based in many applications. One of the greatest advantages is its bandwidth. In the 1960s, modern optical fiber was created.