Why HTTP3 QUIC uses UDP instead of TCP
This question is very obvious, why HTTP3 Quic uses UDP even it is not reliable enough like TCP. There are lots of limitation in TCP which can be solved using UDP let’s discuss these problems and see how UDP based QUIC is able to solve these problems.
Basic Terminology to understand this article
UDP: It is a transport layer protocol of TCP/IP model, it is connectionless ,fast but not much reliable.
TCP: It is also works on transport layer but it is secured ,connection oriented and reliable for sending packets over internet.
QUIC: Used by HTTP/3. Transport layer network protocol called QUIC, which runs over User Datagram Protocol (UDP) internet protocol instead of the TCP used by all previous versions of HTTP.
Difference between TCP and UDP :
UDP features leveraged by QUIC :
(1) UDP allows multidirectional broadcasting of messages which is solving head of line(HOL) at the packet level.
(2) QUIC is built at the user level, so it doesn’t require changes in the kernel with every protocol upgrade
(3) Support for Streaming of data.
(4) UDP handles congestion more efficiently then TCP.
(5) Optimized handshaking : QUIC can remember the connection which eliminate repeat connections although QUIC is also using TLS but they are using UDP instead of TCP.
Conclusion: These are main reason for swiching the protocol in HTTP/3. You can find best use cases of HTTP are Internet of things(IOT), Microservices etc.
I hope this article help you. Let me know your feedback in comments. Thank you🙏
