1. Add a switch between Optical Cat and the router and assign it to the router and application server. No routing function is required. The communication company gave you five fixed IPS, and the server can directly use the external IP. Since it is a server, it is recommended to build a firewall. Internet machines are equipped with firewalls in terms of routing and routing.

2. Optical fiber, referred to as optical fiber for short, is a light transmission tool based on the principle of total reflection of light in fibers made of glass or plastic. Optical fiber was invented by Gao Kun, former president of the Chinese University of Hong Kong. The tiny optical fiber is encapsulated in a plastic sheath, so it can be bent without breaking. Generally, the emitting device at one end of optical fiber uses light emitting diode (LED). A diode (LED) or a laser beam transmits light pulses to an optical fiber, and a receiving device at the other end of the optical fiber uses a photosensitive element to detect the pulses. In daily life, optical fiber is used for long-distance information transmission because the transmission loss of light in optical fiber is much lower than that of electricity in wires.

3. At present, the optical fiber used in communication is generally timely optical fiber. The timely chemical name is silica (SiO2), which is the same as the main composition of sand used in our daily buildings. However, optical fibers made of ordinary time-sensitive materials cannot be used for communication. Communication optical fiber must be made of high-purity materials; However, doping a small amount of dopant into the main material can make the refractive index of the core and cladding slightly different, which is beneficial to communication.