FC0-U71 Infrastructure Practice Question
Which device converts the signal from an ISP (e.g., cable or fiber) into a digital signal that a home network can use?
⚠ Common exam trap
The trap is selecting 'router' because modern home gateways combine functions; the question specifically asks which device converts the ISP signal, which is the modem's role.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
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Modem
A modem (modulator-demodulator) converts the analog or optical signal from an ISP's cable, DSL, or fiber connection into a digital signal that the home network can use. It is the demarcation device between the ISP's medium and the customer's equipment.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
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Access point
Why it's wrong here
An access point bridges wireless clients onto an existing wired LAN, extending coverage; it performs no ISP signal demodulation. It tempts because it sits at the network edge in home setups, but the modem is the device that converts cable or fibre signalling into Ethernet-ready digital data.
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Router
Why it's wrong here
A router forwards packets between IP subnets and provides NAT, DHCP and firewall functions, but it does not demodulate cable or fibre signalling. It tempts because home gateways often integrate modem and router, yet the conversion from ISP medium to digital Ethernet is performed by the modem.
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Switch
Why it's wrong here
A switch forwards frames between ports within one LAN using MAC addresses; it cannot demodulate cable or fibre ISP signalling. It tempts because it is the central wired device in many home networks, but signal conversion from the ISP medium is the modem's role, not the switch's.
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Modem
Why this is correct
A modem performs the required modulation/demodulation, translating the ISP's analogue carrier signal on cable or fibre into digital Ethernet frames the home router and devices can process. This directly satisfies the stem's constraint of converting the incoming ISP signal into a usable digital signal, unlike a switch, router or access point.
About these practice questions
Courseiva writes every FC0-U71 question from scratch — 988 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official CompTIA exam blueprint
This FC0-U71 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 FC0-U71 exam.