ISC2 CC Network Security Practice Question

Which protocol operates at the Transport layer and provides reliable, connection-oriented data delivery?

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 (Transmission Control Protocol) uses a three-way handshake, sequencing, and acknowledgments to ensure reliable delivery.

Answer analysis

For each option: why learners choose it and why it is or isn't the right answer here.

✓
TCP
Why this is correct
TCP operates at the Transport layer and provides reliable, connection-oriented delivery through handshaking, sequence numbers and acknowledgements. UDP, its Transport-layer counterpart, is connectionless and unreliable, so TCP uniquely satisfies both the layer and reliability constraints stated in the question.
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UDP
Why it's wrong here
UDP sits at the Transport layer but is connectionless and unreliable, offering no handshakes, acknowledgements or retransmission. It is tempting because it shares TCP's layer and port addressing, yet its best-effort datagram model directly contradicts the reliable, connection-oriented delivery the question demands.
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IP
Why it's wrong here
IP operates at the Network layer, providing connectionless, best-effort packet delivery with no reliability or session establishment. It is tempting because TCP and UDP both run over IP, but IP itself offers no acknowledgements, sequencing or handshake, so it cannot satisfy the connection-oriented requirement.
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HTTP
Why it's wrong here
HTTP is an Application-layer protocol that relies on TCP for transport; it defines request and response semantics rather than reliable delivery itself. It is tempting because HTTP sessions appear connection-oriented, but the reliability and connection handling come from the underlying TCP, not HTTP.

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