What protocol do network applications use that can tolerate unreliability for very low latency?

The User Datagram Protocol (UDP) is designed for scenarios where speed is critical and some data loss can be tolerated. Unlike connection-oriented protocols like Transmission Control Protocol (TCP), UDP does not establish a connection before sending data and does not guarantee the delivery of packets. This makes it especially suitable for applications such as real-time audio or video streaming, online gaming, or voice over IP (VoIP), where low latency is a priority and occasional dropped packets don’t significantly affect the overall experience. By foregoing the overhead of error-checking and retransmission, UDP allows for faster transmission of data.

In contrast, Transmission Control Protocol ensures reliable transmission by establishing a connection, ensuring that packets arrive in order and without errors. This reliability can introduce latency, which is why it’s not suitable for applications that prioritize speed over accuracy. Internet Control Message Protocol primarily handles error messages and operational information related to the data being sent across networks rather than functioning as a data transfer protocol. File Transfer Protocol is also a connection-oriented method that provides reliable delivery of files but is not optimized for low-latency requirements.