Which of the following statements are TRUE regarding the characteristics of fiber optic cabling compared to copper cabling in networking? (Choose TWO)
Correct Answer: B,D
Detailed Explanation: Analyzing the Options and Comparing Fiber and Copper: A. Fiber optic cabling is generally less expensive to install and maintain than copper cabling. This statement is FALSE. Generally, fiber optic cabling is more expensive than copper in terms of initial installation and maintenance. Material Costs: Fiber optic cable itself and fiber connectors are often more expensive than copper cable and RJ45 connectors. Installation Complexity: Fiber optic installation often requires specialized skills, tools (like fusion splicers, specialized termination equipment), and more careful handling due to the fragility of glass or plastic fibers. Copper cabling installation is generally simpler and faster. Maintenance and Repair: Fiber optic cable repairs can be more complex and require specialized equipment (OTDRs - Optical Time Domain Reflectometers for fault location, fusion splicers for splicing breaks). Copper cable repairs can often be simpler. Electronics: Fiber optic systems require optical transceivers (SFPs, GBICs, etc.) at both ends to convert electrical signals to light and back. These transceivers add to the cost. While copper systems also use transceivers for longer distances (like 10GBASE-T), for shorter runs copper is often more cost-effective in electronics. However: In certain long-term scenarios, the operational costs might be lower for fiber in some respects due to lower power consumption over long distances, but the upfront and maintenance costs are typically higher for fiber. B. Fiber optic cabling is immune to electromagnetic interference (EMI) and radio frequency interference (RFI). This statement is TRUE. This is a major advantage of fiber optic cabling. Non-Conductive Material: Fiber optic cable uses glass or plastic fibers to transmit light pulses. These materials are non-conductive and are not affected by electromagnetic fields or radio waves. EMI/RFI Immunity Benefits: This immunity makes fiber optic cabling ideal for environments with high levels of electrical noise, near power lines, industrial machinery, or in areas with strong radio transmissions. Copper cabling, being metallic, is susceptible to EMI and RFI, which can degrade signal quality and introduce errors. Shielded copper cables (STP) offer some EMI/RFI protection but are still not as immune as fiber. C. Copper cabling typically supports higher bandwidth and longer distances than fiber optic cabling. This statement is FALSE. This is the opposite of reality. Fiber optic cabling generally supports much higher bandwidth and longer distances than copper cabling. Bandwidth Capacity: Fiber optic cable has a significantly larger bandwidth capacity than copper. Single-mode fiber can support extremely high data rates (400 Gbps, 800 Gbps and beyond) over long distances. While copper technology has improved (e.g., Cat 6a, Cat 8), it still has limitations in bandwidth and distance compared to fiber. Distance Limitations: Copper cabling, especially Ethernet over twisted pair, has distance limitations (e.g., 100 meters for standard Ethernet over Cat 5e/6/6a). Signal attenuation and degradation become significant over longer copper runs, limiting bandwidth. Fiber optic cabling can support distances ranging from hundreds of meters to kilometers (depending on fiber type, wavelength, and transceiver technology) while maintaining high bandwidth. Single-mode fiber, in particular, excels at long-distance transmission. D. Fiber optic cabling is more secure as it is much harder to tap and eavesdrop on compared to copper cabling. This statement is TRUE. Fiber optic cabling provides better physical security than copper. Difficult to Tap: Tapping into a fiber optic cable to intercept data without detection is significantly more difficult and requires specialized equipment and expertise. Any attempt to physically tap fiber often disrupts the light transmission and can be detected. Eavesdropping on Copper: Copper cabling is more vulnerable to eavesdropping. Signals in copper cables can be intercepted using inductive taps or by monitoring electromagnetic radiation. Specialized equipment can be used to tap into copper cables with less physical disruption. Security Benefit: Fiber's inherent resistance to physical tapping makes it a preferred choice for environments where data security and confidentiality are critical, such as financial institutions, government networks, and critical infrastructure. E. Copper cabling is generally more suitable for outdoor deployments due to its greater durability and resistance to environmental factors. This statement is FALSE. While copper cable can be designed for outdoor use (with appropriate jacketing and shielding), fiber optic cabling can also be robustly constructed for outdoor environments and has its own advantages for outdoor deployments. Environmental Resistance of Fiber: Outdoor-rated fiber optic cables are designed to withstand harsh environmental conditions, including temperature extremes, moisture, UV radiation, and physical stress. Specialized jackets and protective layers are used. Durability Considerations: Copper, especially unshielded twisted pair (UTP), can be more susceptible to corrosion, moisture damage, and degradation in harsh outdoor environments if not properly protected. While outdoor-rated copper cables exist, fiber's inherent immunity to electrical issues and ground loops can be advantageous outdoors, especially for long runs. Overall Suitability Depends: The suitability for outdoor deployment depends on specific environmental factors and application requirements. Both copper and fiber can be used outdoors, but fiber is not inherently less suitable. Why Options B and D are Correct: Options B and D accurately highlight key advantages of fiber optic cabling compared to copper: immunity to EMI/RFI and enhanced physical security against tapping. Why Options A, C, and E are Incorrect: Options A, C, and E present inaccurate comparisons between fiber and copper regarding cost, bandwidth/distance, and outdoor suitability. In general, fiber is more expensive, offers higher bandwidth and longer distances, and is not inherently less suitable for outdoor use (in fact, in many outdoor long-haul scenarios, it is preferred). In Conclusion: Fiber optic and copper cabling have distinct characteristics, advantages, and disadvantages. Fiber excels in bandwidth, distance, EMI/RFI immunity, and security, but is typically more expensive and can be more complex to install and maintain. Copper is often more cost-effective for shorter distances and simpler deployments, but is limited in bandwidth and distance and is susceptible to EMI/RFI and physical tapping. Understanding these trade-offs is essential for making informed decisions about cabling infrastructure in network design. This question tests not just factual recall but also a deeper understanding of the practical implications of choosing one cabling type over another.
This CCNA practice question helps students prepare for Cisco networking certification exams by testing knowledge of network fundamentals, routing, switching, and network security concepts.