THE BEECHMONT CREST NETWORKING GUIDE:
ONLINE GUIDE TO NETWORKING / NETWORK + EXAM OBJECTIVES
Part II: Network Media and Cabling
Fiber-optic cable
Fiber-optic cable carries light transmissions rather than electronic signals. This factor makes FDI virtually immune to crosstalk, EMI and signal attenuation. Fiber-optic cable also provides more data security/confidentiality than other forms of media.
Nevertheless, fiber-optic cable does have some key disadvantages. It is very expensive and difficult to install. Therefore, a relatively small number of networked organizations are able to employ it.
At the center of a fiber optic cable is a glass fiber. The glass fiber is surrounded by a silica cladding. Over the cladding is a silicon coating and a structural guard layer. The outermost layer of the cable consists of black polyurethane.
There are two basic types of fiber-optic cable: single-mode and multimode. Single-mode fiber-optic cable transmits data with a single beam of light that travels on a direct path inside the cable. Multimode fiber-optic cable transmits data via numerous beams of light, which bounce about inside the cable. Not surprisingly, the single-mode variety carries data greater distances, and allows for higher transfer speeds.