README

🚀 Pure PHP implementation of SRT (Secure Reliable Transport) protocol

📋 Table of Contents

Overview
Key Features
Installation
Quick Start
Configuration
Dependencies
Architecture
Advanced Usage
Examples
Testing
Documentation
Contributing
License

📋 Overview

tourze/srt-php is a pure PHP implementation of the SRT protocol, providing low-latency, high-reliability real-time data transmission capabilities for PHP developers.

🎯 Key Features

✅ Secure Encryption: AES-128/192/256-CTR encryption support
✅ Reliable Transport: Automatic Repeat reQuest (ARQ) mechanism
✅ Low Latency: Live mode TSBPD support
✅ Adaptive: Smart congestion control and flow management
✅ High Performance: Precise RTT estimation and network condition assessment

Installation

composer require tourze/srt-php

Quick Start

Basic Usage

<?php
use Tourze\SRT\Crypto\EncryptionManager;
use Tourze\SRT\Live\TsbpdManager;
use Tourze\SRT\Control\RttEstimator;

// 1. Encryption functionality
$encryption = new EncryptionManager(
    EncryptionManager::ALGO_AES_256,
    'your_secret_passphrase'
);

$encrypted = $encryption->encryptPacket($data, $sequenceNumber);
$decrypted = $encryption->decryptPacket($encrypted, $sequenceNumber);

// 2. Live mode TSBPD
$tsbpd = new TsbpdManager(120); // 120ms playback delay
$tsbpd->addPacket($data, $timestamp, $sequenceNumber);
$readyPackets = $tsbpd->getReadyPackets();

// 3. RTT estimation
$rttEstimator = new RttEstimator();
$rttEstimator->updateRtt($measuredRtt);
$networkCondition = $rttEstimator->getNetworkCondition();

⚙️ Configuration

The package supports various configuration options for optimal performance:

Encryption Configuration

// Basic configuration
$encryption = new EncryptionManager(
    EncryptionManager::ALGO_AES_256,  // Algorithm
    'your_secret_passphrase'          // Passphrase
);

// Advanced configuration with key rotation
$keyManager = new KeyManager();
$keyManager->generateKey(256);
$encryption->updateKey($keyManager->getKey());

TSBPD Configuration

// Configure playback delay and drift compensation
$tsbpd = new TsbpdManager(120);
$tsbpd->enableDriftCompensation(true);
$tsbpd->setMaxDrift(10);

Dependencies

This package requires:

PHP: ^8.1
Extensions:
- ext-filter: Data filtering and validation
- ext-hash: Cryptographic hashing functions
- ext-openssl: SSL/TLS encryption support
- ext-sodium: Modern cryptographic library

🏗 Architecture

src/
├── Crypto/              🔐 Encryption & Security Module
│   ├── EncryptionManager.php
│   └── KeyManager.php
├── Live/                ⏰ Live Mode Features
│   └── TsbpdManager.php
├── Control/             🌊 Flow & Congestion Control
│   ├── FlowControl.php
│   ├── CongestionControl.php
│   ├── RttEstimator.php
│   └── TimerManager.php
├── Protocol/            📦 Protocol Implementation
├── Transport/           🚚 Transport Layer
└── Exception/           ⚠️ Exception Handling

Advanced Usage

🔐 Encryption & Security

use Tourze\SRT\Crypto\EncryptionManager;
use Tourze\SRT\Crypto\KeyManager;

// Advanced encryption setup
$keyManager = new KeyManager();
$keyManager->generateKey(256); // Generate 256-bit key

$encryption = new EncryptionManager(
    EncryptionManager::ALGO_AES_256,
    $keyManager->getKey()
);

// Key rotation
$keyManager->rotateKey();
$encryption->updateKey($keyManager->getKey());

🌊 Flow Control & Congestion Management

use Tourze\SRT\Control\FlowControl;
use Tourze\SRT\Control\CongestionControl;
use Tourze\SRT\Control\RttEstimator;

// Advanced flow control
$flowControl = new FlowControl(100, 1000000); // Window size: 100, Rate: 1Mbps
$congestionControl = new CongestionControl();
$rttEstimator = new RttEstimator();

// Adaptive rate control based on network conditions
$networkCondition = $rttEstimator->getNetworkCondition();
$adaptiveRate = $congestionControl->calculateOptimalRate($networkCondition);
$flowControl->updateSendingRate($adaptiveRate);

⏰ Time-Based Packet Delivery (TSBPD)

use Tourze\SRT\Live\TsbpdManager;

// Advanced TSBPD configuration
$tsbpd = new TsbpdManager(120); // 120ms playback delay

// Configure drift compensation
$tsbpd->enableDriftCompensation(true);
$tsbpd->setMaxDrift(10); // 10ms maximum drift

// Add packets with precise timing
$tsbpd->addPacket($data, $timestamp, $sequenceNumber);

// Get ready packets with statistics
$readyPackets = $tsbpd->getReadyPackets();
$stats = $tsbpd->getStats();

📊 Phase 3 Complete Features

🔐 Encryption & Security Module

EncryptionManager: Support for AES-128/192/256-CTR encryption
KeyManager: Key generation, storage, rotation, and exchange
Support for PBKDF2 and HKDF key derivation
Automatic key update mechanism
Key strength validation and entropy detection

🌊 Advanced Flow Control

RttEstimator: RFC 6298 standard RTT estimation
Network jitter detection and stability scoring
Adaptive window size recommendations
Intelligent network condition assessment (excellent/good/fair/poor/terrible)
BDP (Bandwidth-Delay Product) calculation

⏰ Live Mode TSBPD

TsbpdManager: Timestamp-based packet delivery
Precise playback delay control (default 120ms)
Automatic clock drift compensation
Intelligent late packet dropping
Real-time latency statistics and monitoring

📈 Performance Enhancements

Improved congestion control algorithm integration
Precise RTO calculation
Network condition adaptive adjustment
Comprehensive statistics and monitoring system

🧪 Examples

Run Basic Demo

cd packages/srt-php
php examples/basic_usage.php

Run Phase 3 Advanced Demo

cd packages/srt-php
php examples/phase3_demo.php

🧪 Testing

./vendor/bin/phpunit packages/srt-php/tests/

📈 Development Progress

Version	Feature Scope	Status
v0.1.0	Basic UDP + Simple Handshake	✅ Complete
v0.2.0	Data Transfer + ACK/NAK	✅ Complete
v0.3.0	Encryption + Flow Control + Live Mode	✅ Complete
v0.4.0	Performance Optimization	🟡 Planned
v1.0.0	Production Ready	🟡 Planned

🎯 Performance Metrics

✅ Latency: <120ms (Live mode)
✅ Throughput: >10Mbps
✅ Reliability: 99.9% packet transmission success rate
✅ Security: AES-256 encryption protection

📚 Documentation

Development Plan - Detailed development planning and progress
API Documentation - Complete API reference
Example Code - Usage examples and demonstrations

🤝 Contributing

Contributions are welcome! Please follow these steps:

Fork the project
Create a feature branch: git checkout -b feature/amazing-feature
Commit your changes: git commit -m 'Add amazing feature'
Push to the branch: git push origin feature/amazing-feature
Create a Pull Request

License

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

🔗 Related Links

Last updated: 2025-01-27
Current version: v0.3.0
Project status: 🟢 Phase 3 Advanced Features Complete

tourze / srt-php

Maintainers

Details