Which of the following cable types would be used to wire a LAN network, above drop ceilings, in an area susceptible to EMI?
Explanation
Answer: A - Cables placed above drop ceilings in areas of high EMI should be plenum-rated STP.
Key Takeaway - Plenum-rated cable is specially made to meet fire-code, as it will not release toxic chemicals when burned (unlike many other cables). As a result, when placing cable between floors or behind walls, plenum-rated cable needs to be used. Twisted Pair (UTP) cabling was created to reduce cross-talk in Ethernet networks, and Shielded Twisted Pair (STP), was developed to reduce the vulnerability of UTP to Electromagnetic Interference (or EMI). Coaxial cable is still used in some networks (for instance in Cable Internet), but is not often used in LAN environments.
