Cisco Certified Support Technician (CCST) NetworkingNetworking FundamentalsMedium
A network administrator is troubleshooting connectivity issues on a wired Ethernet network. They notice that some cables are very susceptible to electromagnetic interference (EMI) from nearby fluorescent lights and machinery. Which type of Ethernet cable is most resistant to EMI due to its shielding?
- AShielded Twisted Pair (STP)
- BFiber Optic
- CUnshielded Twisted Pair (UTP)
- DCoaxial
Show answer & explanationAnswer & explanation
Correct answer: A. Shielded Twisted Pair (STP)
Shielded Twisted Pair (STP) cables include an extra layer of foil or braided mesh shielding around the twisted pairs, which significantly protects against electromagnetic interference (EMI) and radio frequency interference (RFI).
Why the other options are wrong
- B. Fiber optic cable uses light signals and is completely immune to EMI, but it's not a twisted pair Ethernet cable type.
- C. UTP cables lack shielding and are more susceptible to EMI.
- D. Coaxial cable is typically used for cable TV and older network types, not standard modern Ethernet, and has different shielding characteristics.
Shielded Twisted Pair (STP)
A type of copper networking cable that contains an outer metallic foil or braid shielding layer in addition to the twisted pairs, designed to reduce electromagnetic interference (EMI) and improve signal integrity.
- Offers better EMI/RFI protection than UTP.
- More expensive and thicker than UTP.
- Requires proper grounding for effective shielding.
Memory trick: Shielding makes cables strong against the storm.