# 傳輸層與應用層協定

IETF 的 QUIC 是一個傳輸層協定，在該協定之上可以運行其他應用層協定。初始的應用層協定是 HTTP/3（ h3 ）。

傳輸層協定負責連接和串流的處理。

在Google 舊版 QUIC 中，已將傳輸和 HTTP 粘合在一起，成為一個單一的 "do-it-all" 工具。 它的用途更加特殊，是一個更有指向性的 send-http/2-frames-over-udp 的協定。


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# Agent Instructions: 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:

```
GET https://http3-explained.haxx.se/zh-tw/the-protocol/feature-trans-app.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
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.