Which protocol is preferred for applications that require real-time communication like voice and video?

For applications that require real-time communication, such as voice and video, the User Datagram Protocol (UDP) is preferred. This preference is primarily due to the nature of real-time applications, where timely delivery of data is crucial. UDP allows for faster transmission because it does not establish a connection prior to sending data, nor does it ensure that all packets arrive or are delivered in order. This characteristic is beneficial for voice and video communications where maintaining flow and minimal latency are more important than ensuring every packet is received perfectly.

In contrast, protocols like TCP (Transmission Control Protocol) focus on reliability and data integrity. TCP provides connection-oriented communication, requiring acknowledgment for each segment of data sent, which can introduce delays not suitable for real-time communication. HTTP (Hypertext Transfer Protocol) is designed for transferring web content, and while it can use TCP, it is not optimized for real-time data transmission. SCCP (Skinny Client Control Protocol), while relevant in VoIP contexts, is less commonly used compared to UDP for direct packet transmission, especially in environments prioritizing low latency.

Thus, UDP's lightweight and connectionless nature makes it the optimal choice for applications that demand real-time performance, enabling smoother and more efficient communication for voice and video applications.