Fiber-optic cabling is widely used for high-speed Ethernet links over relatively long distances. It uses glass or plastic fiber as a medium through which light is “guided” to the other end of the link. The fiber-optic cable itself has several layers made from different materials and having different functions. The most important layer is the core, which is the very center of the cable. A light source, called transmitter or Tx, shines a light into the core. The core itself is surrounded by optical material called the cladding that keeps the light in the core using an optical technique called total internal reflection. Together the cladding and core create the environment to allow transmission of light over the cable.

Network infrastructure and security are critical aspects of information technology that involve the design, implementation, and management of a network to ensure its availability, reliability, and protection against unauthorized access or attacks.