README.md

doc_id	NET-GUID-028
doc_title	QUIC Protocol Support
doc_version	1.0.0
doc_date	2026-04-04
doc_status	Released
project	network_system
category	GUID

QUIC Protocol Support

SSOT: This document is the single source of truth for QUIC Protocol Support.

Overview

network_system provides native QUIC protocol support implementing RFC 9000, RFC 9001, and RFC 9002. The implementation follows the same design philosophy as other protocols in the library: direct RFC implementation with minimal external dependencies.

Key Features

• RFC 9000/9001/9002 Compliance: Full implementation of QUIC transport, TLS 1.3 integration, and congestion control
• TLS 1.3 Built-in Security: Mandatory encryption with modern cryptographic standards
• Stream Multiplexing: Multiple concurrent streams over a single connection without head-of-line blocking
• Connection Migration: Maintain connections across network changes (NAT rebinding support)
• 0-RTT Resumption: Fast reconnection with early data support
• Consistent API: Follows existing messaging_*_client/server patterns

Quick Start

Server

#include "kcenon/network/core/messaging_quic_server.h"

using namespace network_system::core;

int main() {
    auto server = std::make_shared<messaging_quic_server>("my_server");

    // Configure callbacks
    server->set_connection_callback([](auto session) {
        std::cout << "Client connected: " << session->session_id() << "\n";
    });

    server->set_receive_callback([](auto session, const auto& data) {
        std::cout << "Received " << data.size() << " bytes\n";
    });

    // Start server
    if (auto result = server->start_server(4433); result.is_ok()) {
        std::cout << "Server started on port 4433\n";
        server->wait_for_stop();
    }

    return 0;
}

Client

#include "kcenon/network/core/messaging_quic_client.h"

using namespace network_system::core;

int main() {
    auto client = std::make_shared<messaging_quic_client>("my_client");

    // Configure callbacks
    client->set_connected_callback([]() {
        std::cout << "Connected to server\n";
    });

    client->set_receive_callback([](const auto& data) {
        std::cout << "Received: " << std::string(data.begin(), data.end()) << "\n";
    });

    // Configure client
    quic_client_config config;
    config.verify_server = false;  // For testing only

    // Connect
    if (auto result = client->start_client("127.0.0.1", 4433, config); result.is_ok()) {
        // Send data
        client->send_packet("Hello, QUIC!");

        // Create additional streams
        if (auto stream = client->create_stream(); stream.is_ok()) {
            client->send_on_stream(stream.value(), {'d', 'a', 't', 'a'});
        }

        std::this_thread::sleep_for(std::chrono::seconds(5));
        client->stop_client();
    }

    return 0;
}

Documentation Index

Document	Description
Architecture	Implementation architecture and design decisions
API Reference	Complete API documentation
Configuration	Configuration options and tuning
Examples	Usage examples and patterns

Build Configuration

QUIC support is optional and must be enabled at build time:

cmake -DBUILD_QUIC_SUPPORT=ON ..

Dependencies

• OpenSSL 3.0+ (for TLS 1.3 cryptography)
• C++20 compatible compiler
• ASIO (header-only networking)

Comparison with Other Protocols

Feature	TCP	WebSocket	QUIC
Transport	TCP	TCP	UDP
Encryption	Optional (TLS)	Optional (WSS)	Required (TLS 1.3)
Multiplexing	No	No	Yes (Streams)
Head-of-line Blocking	Yes	Yes	No
Connection Migration	No	No	Yes
0-RTT	No	No	Yes

Performance Characteristics

• Latency: Lower connection establishment time (1-RTT or 0-RTT)
• Throughput: Comparable to TCP with better behavior under packet loss
• Concurrency: Multiple streams without blocking each other
• Recovery: Fast loss recovery with RACK-TLP algorithm

Related Issues

• #245 - Epic: QUIC Protocol Support
• #256 - Phase 4.3: Integration Tests and Documentation