Networking Fundamentals Practice Question 2: TCP vs UDP
Networking Fundamentals · Test 1 · question 2 of 10
A developer is building a live voice-chat feature. A packet that arrives late is useless because the conversation has already moved on, so the team wants the lightest transport protocol possible, with no connection setup and no automatic retransmission of lost data. Which transport protocol best fits?
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Answer:
UDP sends messages with a minimum of protocol mechanism. It has no handshake, no acknowledgements and no retransmission, and it doesn't guarantee delivery or ordering. For real-time audio and video that is what you want: a lost packet is skipped instead of holding up everything behind it. So D is correct.
- A is a true statement about TCP, but guaranteed ordered delivery is the problem here. TCP waits for and resends lost segments, so one lost packet delays all the data behind it. That extra delay is what the team is trying to avoid. - B is wrong: the three-way handshake *adds* a round trip before any data flows. It does not lower latency. - C is wrong: UDP does not retransmit at all. If an application needs retransmission over UDP, it has to build that itself.
References: RFC 768 - User Datagram Protocol; RFC 9293 - Transmission Control Protocol