Multi-Tenant VoIP System Development

VoIP System Development Task Document Project Overview Build a multi-tenant VoIP system that allows users to add and manage their own SIP trunks, configure custom Caller IDs and prefixes, and track minute usage. The system must provide billing for users and reconcile minutes with providers. This will be a scalable, secure, and feature-rich platform capable of handling thousands of users and trunks. --- Project Goals 1. User Management: Support 1,000+ users, each managing up to 50 trunks. 2. Custom Configurations: Enable users to set custom prefixes and Caller IDs for each trunk. 3. Billing System: Track and bill users for minutes used and reconcile minutes with the provider. 4. Monitoring: Provide real-time metrics for active calls and system performance. 5. Scalability: Handle thousands of concurrent calls and scale with increasing user base. 6. Security: Ensure secure SIP signaling and web access. --- Key Deliverables 1. Fully configured and scalable VoIP system (Kamailio + FreeSWITCH). 2. User portal for trunk management and billing. 3. Real-time monitoring system with dashboards. 4. Billing integration for user payments and provider reconciliation. 5. Comprehensive documentation for deployment and maintenance. --- Development Steps Phase 1: Infrastructure Setup 1. Provision Servers: 4 servers (Linux OS) for: Kamailio (SIP signaling and routing). FreeSWITCH (media handling). Billing System (AstPP). Monitoring and Analytics (Prometheus + Grafana, HOMER). Hardware Specifications: CPU: 16 cores. RAM: 128 GB. Storage: SSD/NVMe (1 TB). Network: 10 Gbps NIC. 2. Networking: Configure static IPs and firewall rules. Set up QoS for SIP traffic. --- Phase 2: Core VoIP System 1. Install and Configure Kamailio: Handle SIP signaling for: User registrations (custom trunks). Routing calls to providers via LCR (Least Cost Routing). Enable the following modules: dispatcher for load balancing. tm for transaction management. pv for custom SIP header manipulation (e.g., Caller IDs). Add logic for prefix management: Allow users to set custom prefixes per trunk. Apply routing rules based on user-defined prefixes. 2. Install and Configure FreeSWITCH: Handle media (if required, for RTP proxying or Caller ID manipulation). Integrate with Kamailio for SIP-to-media handling. --- Phase 3: User Billing System 1. Install AstPP: Configure AstPP to: Create user accounts (support for 1,000+ users). Track trunk usage per user. Generate invoices based on per-minute usage. 2. Integrate AstPP with Kamailio: Ensure real-time CDR (Call Detail Record) tracking. Set up APIs for fetching billing data for the user portal. --- Phase 4: User Management Portal 1. Backend Development: Language/Framework: Python (Django) or Node.js. Features: User authentication and management. SIP trunk configuration: Add/Edit/Delete trunks. Set custom prefixes and Caller IDs. View usage statistics (active calls, minutes used). Billing history and payment options. 2. Frontend Development: Framework: React.js or Vue.js. Features: Dashboard for users to monitor trunk activity. Intuitive UI for trunk configuration. Integration with backend APIs for real-time data. --- Phase 5: Monitoring and Analytics 1. Set Up Prometheus + Grafana: Collect metrics for: Active calls per user. System health (CPU, RAM, network). Create dashboards for: Admins (system-wide metrics). Users (trunk-specific stats). 2. Install HOMER SIP Capture: Enable SIP packet capture for debugging and troubleshooting. --- Phase 6: Security Implementation 1. SIP Security: Use TLS/SRTP for secure SIP signaling and media streams. Configure Kamailio with Fail2Ban for intrusion detection. 2. Web Security: Enable HTTPS using Certbot (Let's Encrypt). Implement RBAC (Role-Based Access Control) for user roles. --- Functional Requirements --- Developer Milestones 1. Week 1–2: Infrastructure and Core Setup Deploy Kamailio, FreeSWITCH, and initial server configurations. Configure SIP signaling and basic call routing. 2. Week 3–4: Billing System Integration Install and configure AstPP. Test CDR tracking and billing logic. 3. Week 5–6: User Portal Development Build backend APIs for trunk management. Develop frontend dashboard with React.js or Vue.js. 4. Week 7–8: Monitoring and Security Set up Prometheus, Grafana, and HOMER. Implement SIP security and HTTPS. 5. Week 9–10: Testing and Deployment Test system under load (simulate 1,000 users with 50 trunks each). Debug and fix any performance bottlenecks. Prepare final documentation for handover. --- Technical Stack --- Additional Notes Ensure scalability for handling increased call volume (up to 100K concurrent calls in the future). Provide clear documentation for system maintenance and future enhancements. Include unit and integration tests for all critical features. This document should guide the developer in implementing your project effectively. Let me know if you need further clarifications or refinements!