New technologies generate great excitement, but sometimes older technologies continue to serve important needs. An example of such a technology is 100BASE-FX.
Although 100BASE-FX was developed in the mid-1990s, it is still in use today, 10 years later, when we also have Gigabit and 10-Gigabit available. Why? One reason is that 100-FX has the longest range over multimode fiberoptic cable of any Ethernet technology. While 100-FX can reach two kilometers using any quality of multimode fiber, the Gigabit maximum range is 550 meters, and 10-Gigabit maximum range is 300 meters on only the highest-quality multimode fiber. Therefore, there are many 100-FX applications in the current market. Take fiber optic transceivers for example, Cisco GLC-GE-100FX and Cisco GLC-FE-100FX are very popular. Besides,100-FX Ethernet media converter is also widely used.
Fiberoptic cabling provides several benefits over copper cabling: noise immunity, no electromagnetic emissions, and it is difficult to tap or eavesdrop, in addition to supporting long distances. There are two types of fiberoptic cabling: multimode and singlemode. Multimode fiberoptic cabling is much less expensive than singlemode, although singlemode fiber provides greater distances. The 100BASE-FX standard specifies multimode fiber as the transmission medium. Because 100-FX operates over multimode fiber and reaches distances up to two kilometers, there continues to be widespread use of 100-FX as a cost-effective way to extend Ethernet networks. For example, GLC-GE-100FX can operate on ordinary multimode fiber-optic link spans up to 2 kilometers long (shown in the figure below).
Besides above, there are still many other benefits of using 100-FX:
Factories can be difficult environments for computer networks due to many sources of external interference that can affect the signal on copper cabling. For factories, fiber-based networks are often the only option. In large campus environments, fiberoptic cabling is required to reach the distances between buildings. Because of the FDDI legacy, many of those fiberoptic links are constructed of multimode fiber with distances no greater than two kilometers. When 100-Megabit communication is adequate, this campus example is a perfect fit for 100-FX.
Department stores and grocery chains are other examples where 100-Megabit communication is adequate, but the challenges are long distances from the computer room to the point-of-sale devices and cash registers. Again, 100-FX is ideal for such a network. Finally, cost is a big benefit of 100-FX, because 100-FX typically uses LEDs instead of higher-cost lasers. With less expensive transceivers at each end of the link, the overall system cost is lower. Existing multimode fiber segments further reduce the cost by allowing customers to reuse that fiber instead of installing new fiber.
Even 10 years after its creation, 100-FX is a viable technology with compelling reasons for its use. For reasons of low cost components, ability to re-use existing multimode fiber and support for long distances, 100-FX will be in use for many years to come.