Certified Technology Specialist (CTS) Practice Exam

What typically causes Alien Crosstalk (AXT) in a network system?

1. The distance between cables is too great

2. UTP cables are bundled with other low voltage UTP cables

3. The use of outdated equipment

4. Improper cable terminations

The correct answer is: UTP cables are bundled with other low voltage UTP cables

The primary cause of Alien Crosstalk (AXT) in a network system stems from the proximity of unshielded twisted pair (UTP) cables to other low voltage UTP cables within a bundle. AXT occurs when signals from one cable interfere with signals in another cable that is not part of the same system or cable bundle, which is particularly common in environments where multiple cables are closely grouped together. When UTP cables are bundled, the electromagnetic fields emitted due to the transmission of data can overlap with adjacent cables. This phenomenon can introduce complexity in the data signals, leading to crosstalk, which can degrade the overall performance of the network. Proper cable management and spacing are essential to minimize this risk and maintain signal integrity. Other options highlight factors that may affect overall network performance but do not specifically contribute to the phenomenon of Alien Crosstalk. For example, the distance between cables, while important for signal quality, does not directly lead to AXT. Similarly, outdated equipment and improper cable terminations can introduce different types of noise or interference in a network, but they are not the root cause of AXT.