CertiGuide to Security+  9  Chapter 3:  Infrastructure Security (Domain 3.0; 20%)       9  3.2  Media

3.2.2  UTP (Unshielded Twisted Pair) / STP (Shielded Twisted Pair) 1 3.2.4  Removable Media

Before scientists ratcheted up the speed of twisted pair technologies, the main option available to those who wanted faster networking, was fiber. Fiber-optic cabling uses light pulses instead of electrons, as in copper-based technologies, to transmit information.

There are a variety of cable standards, supporting 100mbit/sec (100BaseFX) and 1gbit/sec (1000BaseSX, 1000BaseLX, 1000BaseLH, and 1000BaseZH) Ethernet. A number of connectors may be used as well, from the older SMA connector, to the newer, easier-to-use ST and SC connectors.³⁰⁵

Today fiber is often the cabling of choice within data center environments used to connect systems into fault-tolerant clusters, attach storage area networks, etc. It is also in use where an excess of electrical “noise” in the environment makes twisted pair impractical, such as a factory floor. Fiber also has some additional data-security advantages over copper-based technologies. The cable itself is difficult to “tap” into by someone who wants to add an unauthorized node to the network, and since fiber does not radiate electromagnetic energy, emissions cannot be intercepted.³⁰⁶ It is also resistant to RF interference that might affect other types of cabling, causing transmission errors and dropped packets.

Fiber-optic cable can be challenging to install and maintain, depending on the precise technologies in use. Because fiber-optics involves passing light around a network, it is important for the connections to be as perfect as possible, to minimize the loss of light, and thus signal, at the connection.

In earlier days, fiber optic cable breaks meant major efforts to polish the ends of the broken cable and reattach them, but fortunately, technology has advanced and vendors have introduced easier ways to deal with fiber-optic cable breaks.

As with twisted pair, if you are running fiber in certain locations like suspended ceilings or conduit, be sure that you are using a plenum-certified variety of cable.

Outside the data center, you may also see fiber-optic cable used instead of standard video cable in high-security theft or intrusion alarm systems.

3.2.2  UTP (Unshielded Twisted Pair) / STP (Shielded Twisted Pair) 1 3.2.4  Removable Media