Cisco Certified Network Associate (CCNA) Practice Exam

What type of cabling is used by the standard 1000BASE-CX?

1. Copper cabling

2. Fiber-optic cabling

3. Twinaxial cabling

4. Coaxial cabling

The correct answer is: Twinaxial cabling

The correct answer is that 1000BASE-CX uses twinaxial cabling. This standard is specifically designed for short-distance connections, typically in environments like data centers, where cabling runs are short—often up to 25 meters. Twinaxial cables consist of two copper conductors, which makes them well-suited for high-speed networking, as they can support the necessary bandwidth for gigabit Ethernet. Additionally, twinaxial cabling provides excellent resistance to electromagnetic interference (EMI), making it a good choice for environments with many electronic devices that could cause such interference. Twinax is especially popular for applications involving rack-to-rack connections or between switches in close proximity. In contrast, while copper cabling in general could be used for other networking standards, 1000BASE-CX specifically requires twinaxial cabling due to its unique electrical properties. Fiber-optic cabling is not applicable here as 1000BASE-CX is focused on copper solutions. Coaxial cabling lacks the bandwidth capability required for gigabit speeds, making it unsuitable as well.