Cisco Certified Support Technician (CCST) NetworkingNetworking FundamentalsHard
A network administrator needs to connect two buildings on a campus network with a secure, high-speed wired connection over a distance of 800 meters. There is significant electromagnetic interference (EMI) in the area. Which type of network cable is best suited for this scenario?
- ACat5e UTP
- BMulti-mode fiber optic cable
- CSingle-mode fiber optic cable
- DCoaxial cable
Show answer & explanationAnswer & explanation
Correct answer: C. Single-mode fiber optic cable
Single-mode fiber optic cable is ideal for long distances (over 550 meters for Gigabit Ethernet) and is completely immune to EMI, making it perfect for an 800-meter run in an EMI-prone environment. Multi-mode fiber has distance limitations at 800m for high speeds.
Why the other options are wrong
- A. Cat5e UTP has a maximum distance of 100 meters and is susceptible to EMI.
- B. Multi-mode fiber optic cable has distance limitations (e.g., 550m for 1000BASE-SX) that might be exceeded by 800m, and while immune to EMI, single-mode is better for this distance.
- D. Coaxial cable is typically used for shorter distances and is less common in modern LANs, also susceptible to EMI.
Fiber Optic Cable Types
Fiber optic cables transmit data using light pulses and are categorized by their mode of light propagation: single-mode and multi-mode.
- Immune to electromagnetic interference (EMI).
- Single-mode for long distances, multi-mode for shorter distances.
- Offers higher bandwidth and security than copper cables.
Memory trick: Distance, Interference, Speed: Define the Cable.