Optical fibers are much more advanced nuclear form of data transmission than UTP cabling. Thanks to the use of their special glass fibers, conductors, cables of this type of move higher - Optical - the frequency of the electromagnetic spectrum, which provide higher than in the case of copper cables based on the speed of transmission. The transfer of optical signal between the transmitter and receiver allows so-called phenomenon. propagation of light, or total bounce of light inside the fiber cable.

There are many classifications of this type of wiring, in practice, however - for the design of servers - the most important is a breakdown of the Fiber jednomodowe and dwumodowe. The first one at a time can send only one radius (mod), which limits the phenomenon of distorting the signal inside the line, which allows for the creation of very long cables, the length of which is counted in the hundreds of kilometers. In the case of multimode fiber can transfer many rays albeit at a time is the length of the restriction, even though they may be much longer than copper cables without the need to strengthen the signal.