The answer is that the cable is not shielded (STP). Unshielded twisted pair (UTP) cable lacks the metallic foil or braided shielding that protects against electromagnetic interference (EMI), making it vulnerable to noise sources like fluorescent lights. When a long 50-meter run of UTP Cat6 passes near such lights, the EMI can corrupt the digital signal, causing intermittent VoIP connectivity drops. On the CompTIA A+ Core 1 220-1201 exam, this scenario tests your understanding of how environmental factors degrade network performance—a common trap is assuming Cat6’s higher frequency rating makes it immune to EMI, when in fact shielding is the key differentiator. Remember the mnemonic: “UTP Unprotected, STP Saved.”
220-1201 Cabling Practice Question
This 220-1201 practice question tests your understanding of cabling. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A user complains that their VoIP phone intermittently loses connectivity. The phone is connected to a switch via a 50-meter run of solid-core Cat6 cable. You suspect interference from nearby fluorescent lights. Which cabling characteristic is most relevant to this issue?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The cable is not shielded (STP).
This question tests understanding of electromagnetic interference (EMI) and how it affects network cabling. Unshielded twisted pair (UTP) cable is susceptible to EMI from sources like fluorescent lights, causing intermittent connectivity. The correct answer highlights the lack of shielding as the key factor.
Key principle: NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
The cable is not properly terminated with RJ45 connectors.
Why it's wrong here
Improper termination usually causes complete failure, not intermittent interference.
✓
The cable is not shielded (STP).
Why this is correct
UTP cable lacks shielding, making it vulnerable to EMI from nearby electrical equipment.
Related concept
Static NAT maps one inside address to one outside address.
✗
The cable length exceeds the maximum for Cat6.
Why it's wrong here
Cat6 supports up to 100 meters, so 50 meters is well within limits.
✗
The cable is a crossover cable.
Why it's wrong here
Crossover cables are used for direct device connections, not related to interference.
Common exam traps
Common exam trap: NAT rules depend on direction and matching traffic
NAT is not only about the public address. The inside/outside interface roles and the ACL or rule that matches traffic are just as important.
Detailed technical explanation
How to think about this question
NAT questions usually test address translation, overload/PAT behaviour, static mappings and whether the right traffic is being translated. Read the interface direction and address terms carefully.
KKey Concepts to Remember
Static NAT maps one inside address to one outside address.
PAT allows many inside hosts to share one public address using ports.
Inside local and inside global describe the private and translated addresses.
NAT ACLs identify traffic for translation, not always security filtering.
TExam Day Tips
→Identify inside and outside interfaces first.
→Check whether the scenario needs static NAT, dynamic NAT or PAT.
→Do not confuse NAT matching ACLs with normal packet-filtering intent.
Key takeaway
NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.
Real-world example
How this comes up in practice
A small business has 20 workstations on the 192.168.1.0/24 network and one public IP from its ISP. The router uses PAT (NAT overload) so all 20 devices share one public address using different source ports. NAT questions test whether you understand the four address terms and which direction each translation applies.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this 220-1201 question in full detail.
Review the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related 220-1201 NAT questions on configuration and troubleshooting.
Cabling — This question tests Cabling — Static NAT maps one inside address to one outside address..
What is the correct answer to this question?
The correct answer is: The cable is not shielded (STP). — This question tests understanding of electromagnetic interference (EMI) and how it affects network cabling. Unshielded twisted pair (UTP) cable is susceptible to EMI from sources like fluorescent lights, causing intermittent connectivity. The correct answer highlights the lack of shielding as the key factor.
What should I do if I get this 220-1201 question wrong?
Review the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related 220-1201 NAT questions on configuration and troubleshooting.
What is the key concept behind this question?
Static NAT maps one inside address to one outside address.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
This 220-1201 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 220-1201 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.