Limitations of QUIC and HTTP/3

What is QUIC?

QUIC stands for Quick UDP Internet Connections, it is a general-purpose transport layer protocol that aims to replace the Transmission Control Protocol (TCP) due to its flexibility, built-in security, high performance, and faster adoption rate. QUIC, invented by Google, uses UDP as a low-level transport method to move data packets between clients and servers. Additionally, QUIC includes Transport Layer Security (TLS) as an essential component. QUIC is also supposed to be extremely quick because it uses 0-RTT and 1-RTT (Round Trip Time) handshakes instead of TCP 3-way handshakes. QUIC ensures faster and more accurate data transmission. This stability, along with speed, provides enhanced congestion control and stream retransmission....

What is HTTP/3?

HTTP/3 is a major enhancement over HTTP/2. HTTP/3 aims to enable fast, reliable, and secure web connections across all types of devices by resolving HTTP/2’s transport-related problems. To do this, it employs a separate transport layer network protocol known as QUIC (Quick UDP Internet Connections), which operates on the User Datagram Protocol (UDP) internet than the TCP used by all prior versions of HTTP. Unlike TCP’s, UDP supports multidirectional broadcasting of data, which resolves the issue of head-of-line blocking (HOL)....

Architecture of QUIC

The picture below shows the basic architecture of a QUIC network. QUIC streams are logical objects that hold HTTP/3 requests, responses, or application data. QUIC streams are wrapped in various logical layers for transmission between network endpoints....

How quick is QUIC?

QUIC involves multiplexing, which provides it an advantage over TCP. TCP employs a single end-to-end connection point, but QUIC creates many connections between two endpoints. If one of the streams of information is disrupted, either due to a faulty connection or other external interference, then other connection points will allow the streams to work continue. If a website uses TCP and the connection fails, this may lead to head-of-line blocking(Head of Line blocking refers to the situation in which a browser/client must wait for previous requests to complete, before sending another) , QUIC solves it and QUI also allows efficient and fast data communication....

Benefits of Using QUIC and HTTP/3

Multiplexing: QUIC+HTTP/3 improves network resource utilization and helps prevent the Head of Line Blocking problem using multiplexing. Multiplexing allows several requests and responses to be sent over a single connection, which improves performance by reducing connection overhead and improving network resource utilization. Reduced Latency: Traditional protocols, such as TCP, suffer from latency due to the connection establishment. The multiplexing features of QUIC+HTTP/3 enable them to establish connections more effectively, resulting in less latency when connecting and transmitting data. Faster Connection Establishment: QUIC+HTTP/3 combines the TLS handshake and encryption setup into a single phase, leading to minimizing the number of round trips required to create a secure connection. Improved Error Correction: QUIC includes forward error correction algorithms, which can help recover lost packets without the need for retransmissions, lowering the impact of packet loss on performance. Migration Support: QUIC+HTTP/3 allows for seamless transitions between multiple network connections without interrupting application performance....

Limitations of QUIC and HTTP/3

As QUIC encrypts not just the payload but also the majority of the packet metadata, it becomes more difficult to troubleshoot network issues and optimize networks making network engineers’ jobs more complicated. HTTP/3 is built on QUIC which introduces some additional complexity. QUIC increases the web’s centralization. Implementing HTTP/3 on the server side requires good knowledge and skills....

Is HTTP/3 Available Now?

While the HTTP/3 protocol is still being developed, website owners and visitors should expect HTTP/3 to be supported by browsers, operating systems, and other clients. Of course, the standard, which has already been implemented multiple times, will likely undergo additional modifications. After HTTP/3 is released, the full web will not transit at once to HTTP/3. Many websites do not yet support HTTP/2. One possible difficulty for the new protocol is that it increases CPU utilization on both the server and the client....

Conclusion

In conclusion, QUIC and HTTP/3 show significant developments in internet communication protocols, which offer higher performance, security, and flexibility than previous protocols. HTTP/3 also provides lower latency, and better management of network situations, making it an appropriate protocol for the future of web communications....

Frequently Asked Questions on QUIC and HTTP/3 – FAQs

How does QUIC differ from TCP?...