CDN Glossary

What Are QUIC and HTTP/3?

Quick UDP Internet Connections (QUIC) is an innovative transport layer network protocol that represents a significant advancement in internet technology. Developed initially by Google, QUIC is designed to improve upon the existing Transmission Control Protocol (TCP), which has been a foundational standard for internet communications. The primary aim of QUIC is to provide more efficient, secure, and faster internet connections.

QUIC is built on the User Datagram Protocol (UDP), a core member of the internet protocol suite known for its simplicity and speed. Unlike TCP, UDP is a connectionless protocol, which means it does not require a continuous connection to send data. This characteristic of UDP forms the basis of QUIC’s efficiency, allowing for faster data transmission between client and server.

One of the key features of QUIC is its built-in security. Unlike traditional protocols where Transport Layer Security (TLS) is added as an additional layer, QUIC integrates TLS as an intrinsic component of the protocol. This integration streamlines the process of establishing secure connections, reducing the time and complexity involved in initiating communications.

QUIC addresses several performance issues associated with TCP. For instance, it reduces connection establishment time, minimizes latency through improved congestion control, and handles network changes (like switching from Wi-Fi to cellular data) more gracefully. These improvements are particularly beneficial in a mobile-dominated internet era, where users frequently switch networks.

HTTP/3, the third major version of the Hypertext Transfer Protocol (HTTP), is based on QUIC. Adopted as an IETF standard in 2022, HTTP/3 is designed to overcome some of the limitations of its predecessors (HTTP/1.1 and HTTP/2), particularly those related to the constraints imposed by TCP. By leveraging QUIC, HTTP/3 enhances web browsing experiences through faster page loads, more resilient connections, and improved security.

In essence, QUIC, along with HTTP/3, represents a forward leap in internet protocol technology. It was created to address the inherent limitations of TCP that affect performance and user experience. QUIC’s combination of speed, security, and reliability makes it a significant development in the evolution of internet protocols.