QUIC protocol-Edge Security Acceleration(ESA)-阿里云帮助中心

If the link between a client and a DCDN point of presence (POP) uses the QUIC protocol, data transmission is secured and resource access efficiency improves. This topic describes what QUIC is, how to enable QUIC, and how QUIC is billed.

What is QUIC

QUIC (Quick UDP Internet Connections) is an experimental transport-layer network protocol. QUIC provides security comparable to TLS/SSL while reducing connection delay and transmission delay. Built on UDP, QUIC delivers strong weak-network performance and remains available under severe packet loss and network delay. QUIC supports different congestion control algorithms at the application layer without operating system or kernel support. Compared with TCP, QUIC offers greater flexibility for optimization and suits services that have reached the limits of TCP optimization.

Alibaba Cloud DCDN currently supports QUIC for Layer 7 protocols.

QUIC types

DCDN supports IETF QUIC and Google QUIC. The supported version numbers for Google QUIC are Q39, Q43, and Q46.

IETF QUIC is the Internet standard version.
IETF QUIC is compatible with Google QUIC versions Q39, Q43, and Q46. We strongly recommend that you use IETF QUIC.

How it works

The following figure shows how QUIC works in Alibaba Cloud DCDN.

Client requirements

The QUIC protocol has the following requirements for clients:

If you use Google Chrome, DCDN already supports the standard HTTP/3 protocol, and Chrome can send QUIC requests directly to Alibaba Cloud DCDN.
If you use a self-developed app, the app must integrate a network library that supports the QUIC protocol, such as lsquic-client, Cronet, ngtcp2, or quiche.

QUIC billing rules

QUIC is a value-added service, and additional fees are charged based on the number of QUIC requests. For more information, see the QUIC section in DCDN Pricing Details.

Important

A request is identified as a QUIC request based on whether it uses the UDP protocol.
The billing rule for QUIC requests whose protocol header is HTTPS is as follows: QUIC requests are billed by the number of QUIC requests, and other requests are billed by the number of HTTPS requests.

How to identify QUIC requests

The following example uses Google Chrome to show you how to check QUIC requests.

Procedure: Right-click a blank area on the webpage and select Inspect > Network. If the Protocol column displays h3-29, the request is a QUIC request.

Note If the Protocol column is not displayed, refresh the page and then right-click to select Header Options > Protocol.

In the following figure, "h3" indicates a QUIC request.