- A
TCP
Why wrong: TCP provides reliable delivery with retransmission, which introduces latency and is not suitable for real-time streaming.
- B
UDP
UDP is connectionless, low-latency, and does not retransmit lost packets, making it ideal for VoIP and streaming video.
- C
ICMP
Why wrong: ICMP is used for diagnostic purposes like ping, not for transporting application data.
- D
IGMP
Why wrong: IGMP is used for multicast group management, not for direct data transport.
Question 121 of 520
N10-009 Networking Concepts Practice Question
This N10-009 practice question tests your understanding of networking concepts. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. 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.
Which transport layer protocol is used by VoIP and streaming video because it provides low latency and does not require retransmission?
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
✓
UDP
VoIP and streaming video use UDP (User Datagram Protocol) because it is connectionless and provides low-latency transmission without retransmission of lost packets. This is critical for real-time applications where a slight delay is more disruptive than occasional packet loss.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
TCP
Why it's wrong here
TCP provides reliable delivery with retransmission, which introduces latency and is not suitable for real-time streaming.
When this WOULD be correct
For a question asking which transport layer protocol ensures reliable, ordered delivery of data (e.g., for file transfers, web pages, or email), TCP would be the correct answer because it guarantees retransmission and error checking.
- ✓
UDP
Why this is correct
UDP is connectionless, low-latency, and does not retransmit lost packets, making it ideal for VoIP and streaming video.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
ICMP
Why it's wrong here
ICMP is used for diagnostic purposes like ping, not for transporting application data.
When this WOULD be correct
ICMP would be correct for a question asking: 'Which protocol is used by the ping command to test network connectivity and report errors?' or 'Which protocol is used by routers to send error messages about unreachable destinations?'
- ✗
IGMP
Why it's wrong here
IGMP is used for multicast group management, not for direct data transport.
When this WOULD be correct
A question asking: 'Which protocol is used by a host to join a multicast group to receive streaming video?' would have IGMP as the correct answer, as it manages group membership for multicast traffic.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The N10-009 exam frequently reuses these exact scenarios with slightly different constraints.
✓UDPCorrect answer▾
Why this is correct
UDP is connectionless, low-latency, and does not retransmit lost packets, making it ideal for VoIP and streaming video.
✗TCPWrong answer — click to see why▾
Why this is wrong here
TCP provides reliable, connection-oriented delivery with retransmission of lost packets, which increases latency and is unsuitable for real-time applications like VoIP and streaming video that prioritize low latency over reliability.
★ When this WOULD be the correct answer
For a question asking which transport layer protocol ensures reliable, ordered delivery of data (e.g., for file transfers, web pages, or email), TCP would be the correct answer because it guarantees retransmission and error checking.
Why candidates choose this
Candidates may associate TCP with all internet traffic due to its prevalence in HTTP, FTP, and email, overlooking that real-time media requires a protocol with lower overhead and no retransmission delays.
✗ICMPWrong answer — click to see why▾
Why this is wrong here
ICMP is a network layer protocol used for error reporting and diagnostics (e.g., ping), not for transporting VoIP or streaming video data. It does not provide the low-latency, connectionless transport required for real-time media.
★ When this WOULD be the correct answer
ICMP would be correct for a question asking: 'Which protocol is used by the ping command to test network connectivity and report errors?' or 'Which protocol is used by routers to send error messages about unreachable destinations?'
Why candidates choose this
Candidates may confuse ICMP with UDP because both are connectionless and used in network diagnostics, but ICMP is not a transport layer protocol and does not carry application data like VoIP.
✗IGMPWrong answer — click to see why▾
Why this is wrong here
IGMP (Internet Group Management Protocol) is used for managing multicast group memberships, not for transporting VoIP or streaming video data. It operates at the network layer, not the transport layer, and does not handle low-latency data delivery or retransmission.
★ When this WOULD be the correct answer
A question asking: 'Which protocol is used by a host to join a multicast group to receive streaming video?' would have IGMP as the correct answer, as it manages group membership for multicast traffic.
Why candidates choose this
Candidates may confuse IGMP with UDP because both are associated with multicast streaming, but IGMP is for group management, not data transport.
Analysis generated from the official N10-009blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Common exam traps
Common exam trap: answer the scenario, not the keyword
CompTIA often tests the misconception that 'reliable delivery is always better,' leading candidates to choose TCP, but the trap is that real-time applications prioritize low latency over guaranteed delivery, making UDP the correct choice.
Detailed technical explanation
How to think about this question
UDP's minimal header (8 bytes) and lack of flow control or sequencing overhead allow it to deliver packets with the lowest possible latency, making it ideal for RTP (Real-time Transport Protocol) encapsulation of audio/video streams. In practice, applications like VoIP can tolerate up to 1% packet loss without noticeable degradation, but a TCP retransmission would cause a noticeable gap or stutter. Real-world streaming services often use adaptive bitrate algorithms over UDP to adjust quality based on network conditions rather than relying on retransmission.
KKey Concepts to Remember
- Read the scenario before looking for a memorised answer.
- Find the constraint that changes the correct option.
- Eliminate answers that are true in general but not in this case.
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the N10-009 exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
Quick reference
OSI Model Reference
| Layer | Name | PDU | Key Protocols / Devices |
|---|---|---|---|
| 7 | Application | Data | HTTP, HTTPS, DNS, SMTP, FTP, SSH |
| 6 | Presentation | Data | TLS / SSL, JPEG, ASCII encoding |
| 5 | Session | Data | NetBIOS, RPC, SIP |
| 4 | Transport | Segment / Datagram | TCP, UDP |
| 3 | Network | Packet | IP, ICMP, OSPF — Routers |
| 2 | Data Link | Frame | Ethernet, Wi-Fi, PPP — Switches, Bridges |
| 1 | Physical | Bits | Cables, NICs, Hubs, Repeaters |
What to study next
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FAQ
Questions learners often ask
What does this N10-009 question test?
Networking Concepts — This question tests Networking Concepts — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: UDP — VoIP and streaming video use UDP (User Datagram Protocol) because it is connectionless and provides low-latency transmission without retransmission of lost packets. This is critical for real-time applications where a slight delay is more disruptive than occasional packet loss.
What should I do if I get this N10-009 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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 →
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Last reviewed: Jun 30, 2026
This N10-009 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 N10-009 exam.
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