Build a Custom Multi-Tenant PBX Portal (Asterisk or FreeSWITCH Expert Required)

We are looking for an experienced VoIP developer with deep expertise in Asterisk or FreeSWITCH to build a custom multi-tenant PBX web portal from scratch.

The platform should allow multiple tenants (resellers/customers) to manage their own PBX systems independently — including extensions, SIP trunks, DIDs, call routing, CDRs, billing, and reporting — all accessible through a secure, modern web interface with tenant-level branding.

Our goal is to create a white-label PBX SaaS solution similar to FusionPBX / Thirdlane, but with our own branding, design, and extended billing features.

Key Features:

Tenant Management – Create/edit/delete tenants, assign resources, and define roles (Admin, User, Reseller).

Domain/Subdomain Based Access – Each tenant should access via their own subdomain (e.g., client1.portal.com).

SIP Trunk & DID Management – Add and configure trunks, inbound/outbound routes, and rate plans per tenant.

Extensions & Device Provisioning – Auto-provisioning for IP phones (Yealink, Grandstream, Poly, etc.).

Dialplan Management (GUI) – Web-based visual routing builder with drag & drop or simple forms.

Call Detail Records (CDR) – Tenant-specific call history, filters, reports, and CSV/PDF exports.

Billing & Invoicing – Per-call rating, prepaid/postpaid accounts, monthly invoices, payment gateway integration (Stripe/PayU).

API Access – REST APIs for provisioning, user management, and call data retrieval.

Branding Options – Each tenant can upload their logo and customize their portal theme/colors.

Security & Monitoring – TLS/SRTP, fail2ban, alerts for trunk status, call volume, and resource usage.

Optional Add-ons – WebRTC softphone, CRM integrations (Zoho, HubSpot, Salesforce), or SMS gateway.

Technical Requirements:

Strong experience in Asterisk or FreeSWITCH (dialplans, SIP, RTP, codecs, NAT, SRTP, WebRTC).

Familiar with FusionPBX, FreePBX, or ASTPP is a big plus.

Backend: PHP (Laravel) / Node.js / Python (Django or FastAPI).

Frontend: React.js or Vue.js (modern, responsive design).

Database: PostgreSQL or MySQL with tenant isolation (multi-schema or tenant_id-based).

Deployment: Linux (Debian/Ubuntu), Docker/Kubernetes, Nginx, Let’s Encrypt SSL.

Integrations: Payment gateways (Stripe/PayU), SMTP/Email alerts, SMS APIs.

Version Control: Git, CI/CD pipelines for deployment.

Deliverables:

Functional & technical documentation (architecture, database schema, API list).

Multi-tenant PBX portal (fully functional web-based interface).

REST APIs for provisioning and reporting.

Billing & invoicing system.

Docker/Kubernetes deployment scripts.

Admin & Tenant portals with login.

Testing, security hardening, and 30 days of support post-deployment.

Preferred Skills:-

Deep understanding of VoIP, SIP, RTP, and NAT traversal.

Experience in building large-scale hosted PBX or VoIP billing systems.

Ability to write clean, modular code with scalability in mind.

Familiar with WebRTC (bonus).

Strong English communication and project documentation skills.

Project Phases (Milestones):

Phase 1: Requirement analysis, UI mockups, and system architecture design.

Phase 2: Tenant management, SIP trunk setup, extensions & routing.

Phase 3: Billing system and REST API implementation.

Phase 4: Security, monitoring, and deployment automation.

Phase 5: Testing, optimization, and final delivery with documentation.