Why might TCP not be preferred for VoIP over UDP?

TCP might not be preferred for VoIP over UDP primarily because it can introduce latency. VoIP applications, such as voice calls, require real-time data transmission where timely delivery of packets is crucial for maintaining the flow and quality of the conversation. TCP is a connection-oriented protocol that ensures data is received accurately and in the correct order, which includes error checking and correction mechanisms. While these features enhance reliability, they can lead to delays as the protocol may need to wait for lost packets to be retransmitted or for out-of-order packets to be rearranged before playback.

In contrast, UDP operates as a connectionless protocol, prioritizing speed and efficiency over reliability. It allows packets to be sent without concern for order or delivery, making it more suitable for applications like VoIP, where speed is more critical than perfect accuracy. Thus, the introduction of latency by TCP makes it less favorable for real-time communication needs.