Cisco CCNA (200-301)Network FundamentalsEasy

Which statement accurately differentiates TCP from UDP?

  1. ATCP guarantees delivery through acknowledgments and retransmissions, while UDP provides no delivery guarantee
  2. BUDP establishes a three-way handshake before sending data, while TCP does not
  3. CUDP performs flow control using windowing, while TCP does not
  4. DTCP is used by DHCP and DNS queries because it requires less overhead
Show answer & explanation

Correct answer: A. TCP guarantees delivery through acknowledgments and retransmissions, while UDP provides no delivery guarantee

TCP is connection-oriented and reliable, using sequence numbers, acknowledgments, and retransmissions to guarantee delivery. UDP is connectionless and does not guarantee delivery, ordering, or provide flow control, making it faster but less reliable.

Why the other options are wrong

  • B. The three-way handshake is a TCP feature, not UDP.
  • C. Windowing/flow control is a TCP feature, not UDP.
  • D. DHCP and DNS queries typically use UDP for low overhead, not TCP.

TCP vs UDP

TCP is a reliable, connection-oriented transport protocol; UDP is a fast, connectionless protocol with no delivery guarantees.

  • TCP uses SYN/SYN-ACK/ACK handshake
  • UDP has lower overhead, used for streaming/DNS/DHCP
  • TCP provides flow control via windowing; UDP does not

Memory trick: TCP is a Careful Courier; UDP is an Unreliable Dash.

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