Identified by ISO 11801 standard, multimode fiber optic cables can be classified into OM1 fiber, OM2 fiber, OM3 fiber, OM4 fiber and newly released OM5 fiber. The next part will compare these fibers from the side of core size, bandwidth, data rate, distance, color and optical. Multimode fiber (MMF) is a kind of optical fiber mostly used in communication over short distances, for example, inside a building or for the campus. 5 microns that enables multiple light modes to be propagated. This is made possible by its relatively large core diameter, typically 50 or 62.