> For the complete documentation index, see [llms.txt](https://http3-explained.haxx.se/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://http3-explained.haxx.se/en/proc/proc-ietf.md). # IETF The QUIC working group that was established to standardize the protocol within the IETF quickly decided that the QUIC protocol should be able to transfer other protocols than "just" HTTP. Google-QUIC only ever transported HTTP - in practice it transported what was effectively HTTP/2 frames, using the HTTP/2 frame syntax. It was also stated that IETF-QUIC should base its encryption and security on TLS 1.3 instead of the "custom" approach used by Google-QUIC. In order to satisfy the send-more-than-HTTP demand, the IETF QUIC protocol architecture was split in two separate layers: the transport QUIC and the "HTTP over QUIC" layer - the latter of which was renamed to HTTP/3 in November 2018. This layer split, while it may sound innocuous, has caused the IETF-QUIC to differ quite a lot from the original Google-QUIC. The working group did however soon decide that in order to get the proper focus and ability to deliver QUIC version 1 on time, it would focus on delivering HTTP, leaving non-HTTP transports to later work. In March 2018 when we started working on this book, the plan was to ship the final specification for QUIC version 1 in November 2018 but this has been postponed a number of times. The IETF QUIC protocol was standardized and published in May 2021 as [RFC 9000](https://www.rfc-editor.org/rfc/rfc9000.html). While the work on IETF-QUIC has progressed, the Google team has incorporated details from the IETF version and has started to slowly progress their version of the protocol towards what the IETF version might become. Google has continued using their version of QUIC in their browser and services. [Most new implementations under development](https://github.com/quicwg/base-drafts/wiki/Implementations) have decided to focus on the IETF version and are not compatible with the Google version. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://http3-explained.haxx.se/en/proc/proc-ietf.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.