SIPREC Technical Documentation

Complete technical guide for implementing and deploying SIPREC recording solutions.

Overview

SIPREC (Session Initiation Protocol Recording) is a protocol defined in RFC 7865 and RFC 7866 that enables compliant SIP systems to record call sessions. Our implementation provides a robust, scalable solution for enterprise call recording needs.

// Example: Basic SIPREC initialization
package main

import (
    "github.com/loreste/siprec"
    "log"
)

func main() {
    server := siprec.NewServer(siprec.Config{
        Address: ":5060",
        TLS:     true,
        Storage: "s3://recordings",
    })
    
    if err := server.Start(); err != nil {
        log.Fatal(err)
    }
}

Architecture

System Components

• SIP Proxy: Handles SIP signaling and session establishment
• Media Server: Manages RTP/SRTP streams and transcoding
• Storage Engine: Configurable backend (local, S3, Azure, GCS)
• Metadata Service: Stores call details and indexing
• WebSocket API: Real-time streaming and monitoring

Protocol Flow

┌─────────┐      INVITE      ┌──────────┐      INVITE      ┌─────────┐
│   SRC   │ ───────────────> │  SIPREC  │ ───────────────> │   SRS   │
│  (UA)   │                   │  CLIENT  │                   │ SERVER  │
└─────────┘ <─────────────── └──────────┘ <─────────────── └─────────┘
              200 OK                          200 OK
                    
              ═══════════════════════════════════════════
                        RTP/SRTP Media Flow
              ═══════════════════════════════════════════
                    

High Availability

Our architecture supports active-active clustering with automatic failover:

• Load balancing across multiple recording servers
• Automatic session migration on node failure
• Distributed metadata storage with replication
• Zero-downtime rolling updates

Installation

System Requirements

• Go 1.20 or higher
• Linux (kernel 3.10+), macOS, or Windows Server 2016+
• Minimum 4GB RAM, 8GB recommended
• 10GB disk space for application and logs
• Additional storage for recordings

Quick Start

# Clone the repository
git clone https://github.com/loreste/siprec.git
cd siprec

# Build the binary
make build

# Run with default configuration
./siprec --config config.yaml

# Or use Docker
docker run -p 5060:5060 -p 8080:8080 loreste/siprec:latest

Production Deployment

# Install as systemd service
sudo make install-systemd

# Configure environment
sudo cp .env.example /etc/siprec/.env
sudo nano /etc/siprec/.env

# Start the service
sudo systemctl start siprec
sudo systemctl enable siprec

# Check status
sudo systemctl status siprec

Configuration

Basic Configuration

# config.yaml
server:
  address: ":5060"
  tls:
    enabled: true
    cert_file: "/etc/siprec/cert.pem"
    key_file: "/etc/siprec/key.pem"
  
media:
  port_range: "10000-20000"
  codecs:
    - G.711
    - G.729
    - opus
  
storage:
  type: "s3"
  s3:
    bucket: "call-recordings"
    region: "us-east-1"
    encryption: true
  
metadata:
  type: "postgresql"
  connection: "postgres://user:pass@localhost/siprec"
  
logging:
  level: "info"
  format: "json"
  output: "/var/log/siprec/siprec.log"

Advanced Options

API Reference

REST API

curl -X GET https://api.siprec.local/api/v1/recordings \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "start_date": "2024-01-01",
    "end_date": "2024-01-31",
    "caller": "+1234567890",
    "limit": 100
  }'

curl -X POST https://api.siprec.local/api/v1/recordings/start \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "session_id": "call-123456",
    "participants": [
      {"uri": "sip:alice@example.com", "name": "Alice"},
      {"uri": "sip:bob@example.com", "name": "Bob"}
    ],
    "metadata": {
      "department": "sales",
      "campaign": "Q1-2024"
    }
  }'

WebSocket API

// Real-time streaming example
const ws = new WebSocket('wss://api.siprec.local/ws/stream');

ws.onopen = () => {
    ws.send(JSON.stringify({
        action: 'subscribe',
        session_id: 'call-123456',
        format: 'wav'
    }));
};

ws.onmessage = (event) => {
    const audioData = event.data;
    // Process audio stream
};

Security

Encryption

• Signaling: TLS 1.3 for all SIP communications
• Media: SRTP with AES-256 encryption
• Storage: At-rest encryption using AES-256-GCM
• API: OAuth 2.0 / JWT authentication

Access Control

# Role-based access control configuration
auth:
  provider: "oauth2"
  oauth2:
    issuer: "https://auth.company.com"
    audience: "siprec-api"
  
  roles:
    - name: "admin"
      permissions: ["read", "write", "delete", "manage"]
    - name: "supervisor"
      permissions: ["read", "write", "export"]
    - name: "agent"
      permissions: ["read"]
  
  ip_whitelist:
    - "10.0.0.0/8"
    - "192.168.0.0/16"

Compliance

Our solution meets industry compliance standards:

• PCI DSS Level 1 certified
• GDPR compliant with data retention controls
• HIPAA ready with BAA available
• SOC 2 Type II attestation

Performance

Benchmarks

Optimization Tips

• Use SSD storage for metadata database
• Enable connection pooling for database
• Configure appropriate buffer sizes for your network
• Use CDN for recording playback
• Enable compression for long-term storage

Troubleshooting

Common Issues

# Debug RTP traffic
tcpdump -i any -n port 5060 or portrange 10000-20000

# Check SIPREC logs
tail -f /var/log/siprec/siprec.log | grep -E "RTP|SRTP|codec"

Debug Mode

# Enable debug logging
./siprec --debug --log-level=trace

# Enable SIP message tracing
./siprec --sip-trace --sip-trace-file=/tmp/sip.pcap

# Performance profiling
./siprec --pprof --pprof-addr=:6060