> 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/zh-tw/the-protocol/feature-handshakes.md).

# 快速交握

QUIC 提供 0-RTT 和 1-RTT 的連接建立，這意味著 QUIC 在最佳情況下不需要任何額外往返時間便可以建立新連接。 兩者中較快的 0-RTT 僅在兩主機之間建立過連接且緩存了該連接的 "秘密"（ secret ）時才能使用。

## 早期資料（Early data）

QUIC 允許客戶端在 0-RTT 的情況下直接攜帶資料。這使得客戶端能儘早向對方傳送資料，當然也使得伺服器端能更快地發回響應。


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