Karl Media Server

Karl is a high-performance, production-ready media server designed for handling WebRTC, SIP, RTP, and SRTP communications. It integrates with OpenSIPS, Kamailio and others, supporting real-time media routing, transcoding, and security features like DTLS-SRTP.

🚀 Features

🔹 RTP & SRTP Handling

• Handles RTP and SRTP packets for secure media transmission
• RTP-to-SRTP conversion for interoperability
• Advanced packet loss recovery and jitter buffer optimization
• Robust error handling with metrics

🌍 WebRTC Integration

• Supports WebRTC to SIP calls with DTLS-SRTP
• ICE, STUN, TURN support for NAT traversal
• Real-time WebRTC statistics & logging
• WebRTC to external SIP destinations with codec transcoding

📡 SIP & SIP Proxy Compatibility

• Fully integrates with OpenSIPS and Kamailio
• SIP NAT handling for external call routing
• Failover mechanism for SIP proxy redundancy
• Priority-based load balancing for SIP trunks

🔄 Media Transcoding & Codec Support

• Opus ↔ G.711 transcoding for WebRTC-to-SIP
• Live SDP debugging for call negotiation
• Supports adaptive codec selection for optimal quality

🎥 Recording & Monitoring

• Call recording for WebRTC and SIP users
• Real-time media quality monitoring (packet loss, jitter, bandwidth)
• Prometheus metrics & alerting for media health tracking

🏗️ Highly Configurable

• Dynamic runtime configuration via JSON and .env files
• API-based config updates with WebSocket notifications
• Web-based UI (upcoming) for managing settings & monitoring

☁️ Cloud & NAT Optimizations

• ICE/TURN/STUN support for cloud-based NAT traversal
• Multi-region TURN support for better media relay
• Runs seamlessly on AWS, Google Cloud, and on-prem

⚡ Performance & Scalability

• High-performance RTP handling with low-latency processing
• Optimized for high-throughput SIP/WebRTC calls
• Multi-threaded processing for better concurrency

📋 Requirements

• Go 1.18 or higher
• MySQL/MariaDB for session tracking
• Redis (optional) for caching
• Prometheus (optional) for metrics collection

🛠️ Quick Start

# Clone the repository
git clone https://github.com/karlmediaserver/karl.git
cd karl

# Build the binary
go build -o karl

# Run with default configuration
./karl

See DOCUMENTATION.md for detailed installation and configuration instructions.

📊 Monitoring

Karl provides comprehensive metrics via Prometheus. Access them at:

http://localhost:9091/metrics

📃 Documentation

• Installation Guide
• Configuration Options
• API Reference
• Production Deployment
• Development Guide
• Troubleshooting

📝 License

Karl Media Server is licensed under the GPL 3.0 License - see the LICENSE file for details.