ISC2 CC Network Security Practice Question
Which of the following protocols operates at the Transport layer and provides reliable, connection-oriented communication?
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
✓
TCP
TCP provides reliable delivery via acknowledgments and retransmissions, and uses a three-way handshake to establish a connection. UDP is connectionless and unreliable.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
HTTP
Why it's wrong here
HTTP is an Application-layer protocol that relies on an underlying transport to provide reliability; it does not itself operate at the Transport layer. It is tempting because HTTP traffic commonly runs over TCP, but it would be the correct answer only if the question asked which protocol carries web requests and responses.
- ✓
TCP
Why this is correct
TCP establishes a connection via a three-way handshake and uses sequence numbers, acknowledgements and retransmissions to guarantee ordered, error-free delivery. This connection-oriented reliability at the Transport layer satisfies the stem's requirement, unlike connectionless UDP, which offers no delivery guarantees.
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IP
Why it's wrong here
IP operates at the Network layer, handling logical addressing and routing between hosts, and is connectionless with no reliability mechanisms. It is tempting because IP is fundamental to internet communication, but it would be the correct choice only if the question asked which protocol delivers packets across interconnected networks.
- ✗
UDP
Why it's wrong here
UDP is connectionless and offers no delivery guarantees, retransmission or ordering, so it cannot satisfy the reliable, connection-oriented requirement. It is tempting because UDP also sits at the Transport layer, and would be the right choice where low latency matters more than reliability, such as streaming media or DNS queries.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This CC practice question is part of Courseiva's free ISC2 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 CC exam.