Protocol Optimization

Learning Focus

By the end of this lesson you will understand how modern internet protocols (HTTP/3, TLS 1.3) reduce latency and how to configure them in Cloudflare.

Modern Internet Protocols

Cloudflare allows you to stay at the cutting edge of internet protocols without manual server configuration. Enabling these protocols can significantly reduce the "Time to First Byte" (TTFB) and improve page load speeds.

flowchart LR
    BROWSER["Browser"] -- "HTTP/3 (UDP)" --> CF["Cloudflare Edge"]
    CF -- "HTTP/1.1 / 2 (TCP)" --> ORIGIN["Origin Server"]

    style CF fill:#f6821f,color:#fff,stroke:#e5711e

HTTP/3 (with QUIC)

HTTP/3 is the latest version of the HTTP protocol. Unlike HTTP/1.1 and HTTP/2 which use TCP, HTTP/3 uses QUIC, a protocol built on top of UDP.

Protocol	Transport	Multiplexing	Handshake
HTTP/1.1	TCP	❌ Sequential	3-way
HTTP/2	TCP	✅ Parallel	3-way
HTTP/3	UDP (QUIC)	✅ Parallel	0-RTT / 1-RTT

Why it's faster:

• No Head-of-Line Blocking: In TCP (HTTP/2), if one packet is lost, all others must wait. In QUIC (HTTP/3), a lost packet only affects its own stream.
• Faster Handshakes: Combines transport and security handshakes, saving multiple round-trips to the server.
• Connection Migration: Allows users to switch from Wi-Fi to Mobile data without dropping the connection.

Enable at: Network → HTTP/3 (with QUIC).

TLS 1.3

TLS 1.3 is the latest version of the Transport Layer Security protocol. It is faster and more secure than TLS 1.2.

Aspect	TLS 1.2	TLS 1.3
Handshake	2 round-trips	1 round-trip
0-RTT Support	❌ None	✅ Allowed
Security	Supports legacy (weak) ciphers	Removes legacy ciphers

Enable at: SSL/TLS → Edge Certificates → TLS 1.3.

Early Hints (103 Early Hints)

Early Hints allow Cloudflare to send a response to the browser before the origin server has finished generating the full page. This tells the browser to start downloading critical assets (CSS, JS, Fonts) immediately.

sequenceDiagram
    participant B as Browser
    participant C as Cloudflare
    participant O as Origin

    B->>C: GET /index.html
    C->>O: Forward Request
    Note over C,O: Origin is processing...
    C-->>B: 103 Early Hints (Link: rel=preload style.css)
    B->>C: GET /style.css
    O-->>C: 200 OK (index.html)
    C-->>B: 200 OK (index.html)

Enable at: Speed → Optimization → Content Optimization → Early Hints.

Key Takeaways

• HTTP/3 (QUIC) uses UDP to eliminate head-of-line blocking and speed up handshakes.
• TLS 1.3 reduces the security handshake to a single round-trip.
• Early Hints lets the browser start loading CSS/JS while the server is still thinking.
• All these protocols are free and can be enabled with a single toggle in the Cloudflare dashboard.
• Modern protocols provide the biggest performance gains for users on high-latency networks (Mobile/Satellite).

What's Next

• Continue to Browser Acceleration to optimize your site's physical assets.