Why is UDP favored for real-time applications like voice and video?

• A. Reliability
• B. Lower latency, no connection setup, lower overhead
• C. Guaranteed in-order delivery
• D. Built-in congestion control

Answer: (B)

Real‑time applications care about getting data to the receiver as quickly as possible, even if some data might be lost. UDP fits this need because it is connectionless, so there’s no handshake to set up a session and no retransmission delays. Its header is lightweight, and there’s no built‑in reliability or in‑order delivery, so packets can be sent with minimal overhead and very low latency. In practice, applications can tolerate some loss and implement their own mechanisms (like jitter buffers, selective retransmission, or forward error correction) if needed, while still keeping the stream smooth and timely. If reliability, strict ordering, or automatic congestion control were built into the protocol, the extra signaling, acknowledgments, and pacing would add latency and decrease real‑time performance. That’s why real‑time voice and video often use UDP, sometimes with application‑level protocols layered on top to handle the aspects they prioritize.