CCNA: Cisco Certified Network Associate — Question 1209

Why is UDP more suitable than TCP for applications that require low latency, such as VoIP?

Answer options

• A. UDP uses sequencing data for packets to arrive in order, and TCP offers the capability to receive packets in random order.
• B. TCP uses congestion control for efficient packet delivery, and UDP uses flow control mechanisms for the delivery of packets
• C. UDP reliably guarantees delivery of all packets, and TCP drops packets under heavy load.
• D. TCP sends an acknowledgment for every packet that is received, and UDP operates without acknowledgments.

Correct answer: D

Explanation

The correct answer is D because TCP's requirement for acknowledgments introduces additional latency, making it unsuitable for real-time applications like VoIP. In contrast, UDP's lack of acknowledgment allows for faster transmission of packets, which is essential for low-latency communications. The other options incorrectly describe the functionalities of TCP and UDP, leading to misunderstandings about their use cases.