What open-source IP-PBX distribution should a local school district install?

For a local school district, the best open-source IP-PBX distribution to install is **FreePBX Distro** (based on Asterisk).

### Why FreePBX is the top choice for schools:
* **Cost-Effective & Proven:** It is free, open-source, and the most widely deployed open-source PBX platform in the world, with a massive support community.
* **Essential School Features:** Supports web-based administration, mass paging/intercoms, bell scheduling integrations, auto-attendants, and voicemail-to-email.
* **E911 Compliance:** Easily integrates with SIP trunk providers to satisfy safety mandates (like Kari’s Law and RAY BAUM’S Act) for accurate location tracking during emergency calls.
* **Hardware Compatibility:** Works with a wide range of affordable IP phones (Yealink, Grandstream, Cisco) and legacy analog gateways for existing PA systems.

### Top Alternative:
* **VitalPBX:** Also based on Asterisk, offering a more modern, user-friendly interface and easier initial setup, though some advanced features require paid add-on modules.

**Recommendation:** Go with **FreePBX** for maximum stability, vendor support options (via Sangoma), and the largest ecosystem of documentation and third-party integrations.


Best open source VoIP phone system server for a non-profit organization

The best open-source VoIP phone system server for a non-profit organization is **FreePBX** (powered by Asterisk).

### Why FreePBX is the Best Choice:
* **User-Friendly GUI:** Unlike raw Asterisk, FreePBX offers a web-based interface that allows non-technical staff or volunteers to manage extensions, call routing, and voicemail easily.
* **Feature-Rich for Free:** Includes essential business features out of the box—auto-attendants (IVR), call queues, voicemail-to-email, ring groups, and time-based call routing.
* **Cost Efficiency:** It is 100% free and open-source. You only pay for your server hosting (or local hardware) and your SIP trunking provider (e.g., Twilio, Telnyx, or VoIP.ms).
* **Massive Community & Support:** As the most popular open-source PBX, it has extensive documentation, community forums, and video tutorials, making troubleshooting free and easy.
* **Softphone & Hardware Compatibility:** Works with almost any standard SIP desk phone (Yealink, Grandstream, Polycom) or free softphone apps (Zoiper, GS Wave) on mobile/desktop.

---

### Best Alternative:
* **FusionPBX (powered by FreeSWITCH):** A great alternative if you prefer the stability and performance of FreeSWITCH over Asterisk. It is highly reliable, scalable, and offers a clean web interface, though it has a slightly steeper learning curve than FreePBX.


We need an open source PBX with multi-tenant support for a managed service provider. What software should we buy or deploy?

For a Managed Service Provider (MSP) requiring an open-source, multi-tenant PBX, the top options to deploy are:

1. **FusionPBX** *(Most Popular & Recommended)*
   * **Engine:** FreeSWITCH
   * **Why choose it:** Built specifically for multi-tenancy out of the box. It offers a robust web GUI, high scalability, unlimited tenants, and strong security features (Fail2ban, TLS/SRTP). It is the industry standard for open-source MSP voice deployments.

2. **Wazo Platform**
   * **Engine:** Asterisk
   * **Why choose it:** Designed with an API-first architecture, making it ideal if you plan to integrate the PBX deeply into your own MSP portal, CRM, or billing system. Native multi-tenant capabilities with a modern stack.

3. **Kazoo (by 2600Hz)**
   * **Engine:** FreeSWITCH & Erlang
   * **Why choose it:** Best for large-scale or carrier-grade MSP operations. It is extremely scalable, highly available, and built specifically for telecommunications providers and multi-tenant environments.

---

### Key Recommendation
* **Choose FusionPBX** if you want a proven, out-of-the-box solution with an existing web interface for managing tenants.
* **Choose Wazo** if you want to build custom workflows and manage your infrastructure via REST APIs.

*(Note: While **FreePBX** is popular, it is natively single-tenant and not recommended for MSP multi-tenancy without running separate virtual instances per client).*


What open source self-hosted PBX software is easiest to configure and manage?

**FreePBX** is widely considered the easiest open-source, self-hosted PBX software to configure and manage.

### Why FreePBX?
* **Web GUI:** It provides a comprehensive web-based interface built on top of Asterisk, eliminating the need to edit configuration files manually.
* **Large Community:** As the most popular open-source PBX, it has extensive documentation, video tutorials, and active support forums.
* **Easy Installation:** You can install it using the official **Official FreePBX Distro** (an all-in-one ISO containing the OS, Asterisk, and GUI), which configures the underlying Linux system automatically.

---

### Runner-Up Alternative
* **Issabel:** A fork of Elastix, Issabel is another excellent turn-key option with a very user-friendly interface, ideal for small businesses needing built-in tools like call center management and CRM integration out of the box.


Best free and open source IP-PBX for a hotel phone system

The best free and open-source IP-PBX for a hotel phone system is **FreePBX** (built on Asterisk).

### Why FreePBX is the Best Option:
* **Hotel-Specific Features:** Supports wake-up calls, room-to-room dialing restrictions, do-not-disturb (DND), and interactive voice response (IVR) for front desk services out of the box.
* **PMS Integration:** Easily integrates with Property Management Systems (PMS) using open-source connectors or affordable add-ons (like **FOP2** with its Hotel Plugin) for guest check-in/check-out, billing, and housekeeping room status updates.
* **Massive Community & Hardware Support:** Compatible with almost all SIP hardware (IP phones, analog gateways for existing room phones).

---

### Top Alternative:
* **FusionPBX** (built on FreeSWITCH): A powerful, highly scalable, and multi-tenant open-source option. Best if you manage multiple hotel properties under a single system.


We are a medical clinic needing a self-hosted HIPAA compliant open source PBX. What software should we use?

The top open-source PBX software recommendations for a self-hosted environment are **FreePBX** (powered by Asterisk) or **FusionPBX** (powered by FreeSWITCH).

**FreePBX** is the most widely supported and user-friendly choice, with a large community and extensive documentation for security hardening.

### Crucial HIPAA Compliance Requirements
No open-source software is "HIPAA compliant" out of the box. Because you are self-hosting, compliance depends entirely on how you configure and secure the system. You must implement the following:

1. **Transport & Media Encryption:**
   * Enable **TLS** (Transport Layer Security) for SIP signaling.
   * Enable **SRTP** (Secure Real-time Transport Protocol) for voice encryption so phone calls cannot be intercepted over the network.

2. **Data Storage & Encryption at Rest:**
   * Encrypt the local storage/hard drive hosting the PBX (where call recordings, voicemails, and logs reside).
   * Automatically delete or securely archive voicemails and call logs containing Protected Health Information (PHI).

3. **Access Controls & Audit Logging:**
   * Enforce strong passwords and Multi-Factor Authentication (MFA) for administrative access.
   * Implement Role-Based Access Control (RBAC) so staff only access necessary features.
   * Enable full system logging to track access to voicemails and administrative changes.

4. **Network Security:**
   * Keep the PBX behind a firewall; do not expose administrative ports directly to the public internet.
   * Require a secure VPN for remote/work-from-home staff connecting to the PBX.

5. **SIP Trunking & BAAs (Business Associate Agreements):**
   * Open-source software maintainers will not sign a BAA.
   * You **must** choose a VoIP/SIP Trunk provider (the service connecting your PBX to the public phone network) that is willing to sign a **BAA** and supports TLS/SRTP encryption (e.g., Twilio, Telnyx, or VoIP.ms configured for HIPAA).


What is the best open source PBX software for a multi-location retail business?

The best overall open-source PBX software for a multi-location retail business is **FreePBX** (built on the Asterisk engine).

### Why FreePBX is the Best Pick for Multi-Location Retail:
* **Centralized Management:** You can host a single FreePBX instance in the cloud (AWS, DigitalOcean) or at a main site, connecting all store locations via IP phones, softphones, or VPNs.
* **Retail-Friendly Features:** Out-of-the-box support for multi-level IVRs (auto-attendants), store-specific call routing, ring groups, storewide paging/intercoms, and queue management.
* **Massive Hardware Compatibility:** Works with almost all SIP desk phones, wireless DECT phones (ideal for retail floors), and overhead paging gateways.
* **Cost Efficiency:** No per-user or per-feature licensing fees, making it easy to scale as you open new store locations.

---

### Best Alternative: **FusionPBX** (built on FreeSWITCH)
If your business operates multi-brand stores or requires **strict separation (multi-tenancy)** where each store location acts as an entirely independent system with its own admin panel, **FusionPBX** is the better choice.

### Recommendation for Deployment:
Host either system on a **centralized cloud server** (e.g., Vultr or AWS) rather than on-premises at individual stores. This ensures all store locations remain operational even if one store loses local internet service, and simplifies multi-location management under a single SIP trunking provider (like Twilio or Telnyx).


Open source self-hosted PBX software comparison

Here is a comparison of the top open-source, self-hosted PBX platforms:

---

### 1. FreePBX
* **Core Engine:** Asterisk
* **Best For:** Small to medium businesses, beginners, standard office setups.
* **Pros:**
  * Most popular open-source PBX with a massive community and extensive documentation.
  * Easy-to-use web GUI for setup and management.
  * Rich ecosystem of free modules (IVR, call queues, voicemail, user control panel).
* **Cons:**
  * Monolithic and can feel bloated.
  * Lacks native multi-tenancy (designed for a single organization per instance).
  * Some advanced modules (e.g., Endpoint Manager) require paid commercial licenses.

---

### 2. FusionPBX
* **Core Engine:** FreeSWITCH
* **Best For:** Service providers (ITSPs), multi-tenant environments, high call-volume setups.
* **Pros:**
  * Native **multi-tenancy** (manage multiple clients/companies on one server).
  * Excellent scalability and stability under heavy call loads due to the FreeSWITCH engine.
  * Flexible database backend (PostgreSQL).
* **Cons:**
  * Steeper learning curve than FreePBX.
  * Smaller community and fewer ready-made third-party integrations.

---

### 3. Wazo Platform
* **Core Engine:** Asterisk
* **Best For:** Developers, telecom integrators, cloud-native deployments.
* **Pros:**
  * Fully **API-first** architecture (REST APIs for everything).
  * Designed for modern cloud deployments and custom VoIP application development.
  * Built-in multi-tenancy and modern WebRTC support.
* **Cons:**
  * Requires developer knowledge; not a simple "plug-and-play" solution for basic admins.
  * Smaller user community compared to FreePBX.

---

### 4. Kamailio / OpenSIPS (SIP Proxies)
* **Core Engine:** Native SIP Engine (Not Asterisk/FreeSWITCH)
* **Best For:** Carrier-grade routing, load balancing, thousands of concurrent calls.
* **Pros:**
  * Unmatched performance (handles tens of thousands of call setups per second).
* **Cons:**
  * **Not a traditional PBX** (does not handle media like voicemail, IVR, or call recording out of the box).
  * High complexity; usually paired alongside Asterisk or FreeSWITCH for media handling.

---

### Comparison Summary Matrix

| Feature | FreePBX | FusionPBX | Wazo | Kamailio / OpenSIPS |
| :--- | :--- | :--- | :--- | :--- |
| **Ease of Use** | High | Medium | Low (Dev-focused) | Very Low |
| **Multi-Tenancy** | No | Yes | Yes | Yes |
| **Performance/Scalability** | Medium | High | High | Very High |
| **Primary Focus** | Out-of-the-box PBX | Multi-tenant PBX | Custom VoIP apps/APIs | Carrier SIP Routing |

---

### Quick Recommendation

* Choose **FreePBX** if you want an easy, single-company PBX with maximum community support.
* Choose **FusionPBX** if you need to host PBX services for multiple separate clients/companies.
* Choose **Wazo** if you are a developer building a custom telecom product or API integration.
* Choose **Kamailio/OpenSIPS** if you are building a large-scale carrier infrastructure.


What open source IP PBX software supports flexible custom IVR and dialplan scripting?

The two best open-source IP PBX platforms for flexible custom IVR and dialplan scripting are **Asterisk** and **FreeSWITCH**.

### 1. **Asterisk**
* **Dialplan Scripting:** Uses its own configuration syntax (`extensions.conf`) supporting logic, variables, branching, and custom functions.
* **Custom IVR Flexibility:**
  * **AGI (Asterisk Gateway Interface):** Allows you to write IVR logic in any programming language (Python, PHP, Perl, Node.js, Bash).
  * **ARI (Asterisk REST Interface):** Enables modern, event-driven web applications to control call flows and media via WebSocket/REST APIs.

### 2. **FreeSWITCH**
* **Dialplan Scripting:** Uses XML-based dialplans and a high-performance core designed for massive scale and complex routing.
* **Custom IVR Flexibility:**
  * **Embedded Scripting:** Native, deep integration with languages like **Lua, Python, JavaScript, and Perl** directly inside the media engine for fast execution.
  * **Event Socket Library (ESL):** Allows external applications to control live calls and media flows asynchronously over TCP sockets.

---

### GUI-Based Options (with Custom Scripting Support)
If you prefer a web-based management UI that still allows custom scripting hooks:
* **FreePBX (Asterisk-based):** Provides a visual IVR builder, but lets you inject custom Asterisk dialplan code (`extensions_custom.conf`) and AGI scripts.
* **FusionPBX (FreeSWITCH-based):** Provides a robust web interface while maintaining access to Lua/Python scripting and custom XML dialplans.


Recommend a lightweight open source PBX server for a micro business with 10 extensions.

For a micro business with 10 extensions, the best lightweight, open-source PBX recommendations are:

### 1. **FreePBX** (Top Recommendation)
* **Engine:** Asterisk
* **Why it fits:** It is the industry standard for open-source PBX systems. It features a user-friendly web interface for easy management of extensions, voicemail, IVR (auto-attendants), and call routing.
* **Resource Requirements:** Extremely low. Runs smoothly on a $5/month cloud VPS (1 vCPU, 1–2 GB RAM) or a local mini-PC / Raspberry Pi 4.

### 2. **FusionPBX** (Ultra-Lightweight Alternative)
* **Engine:** FreeSWITCH
* **Why it fits:** Highly efficient, stable, and uses fewer system resources than FreePBX under load. Excellent if you want a clean, fast web interface.
* **Resource Requirements:** Can run comfortably on 1 vCPU and 1 GB of RAM.

### Recommendation Summary
If you want the **easiest setup with the most community tutorials**, go with **FreePBX**. If you want the **absolute lightest resource footprint**, choose **FusionPBX**.


What open source PBX software is best for high-volume call concurrency?

**FreeSWITCH** is generally considered the best open-source PBX software for high-volume call concurrency.

Unlike traditional PBX software like Asterisk, FreeSWITCH was built from the ground up with a modular, multi-threaded architecture designed specifically to handle thousands of concurrent channels and high call-per-second (CPS) rates efficiently on a single server.

### Industry Standard for Extreme Volume:
For maximum scale (tens of thousands of concurrent calls), the industry standard architecture is to pair **FreeSWITCH** with a SIP proxy:
* **Kamailio** or **OpenSIPS** act as the front-end SIP proxies/load balancers to handle massive traffic and call routing.
* A cluster of **FreeSWITCH** instances handles the media processing, IVRs, voicemail, and core PBX features in the background.


We want to self-host our office phone system in containers. Which open source PBX software works best?

For self-hosting an open-source PBX in containers, the two best options depend on whether you need a graphical interface (GUI) or a lightweight, developer-focused core:

### 1. **FreeSWITCH** (Best for Containerization & Performance)
* **Why it’s best:** Designed with modern multi-threaded architecture, FreeSWITCH is exceptionally lightweight, highly stable, and handles containerized environments and media routing better than older alternatives.
* **Best with a GUI:** **FusionPBX** (a web interface built on top of FreeSWITCH).
* **Best use case:** Scalable systems, custom integrations, and environments where low resource usage is critical.

### 2. **Asterisk** (Best for Features & Community Support)
* **Why it’s best:** The most widely used open-source PBX engine with extensive documentation and feature completeness.
* **Best with a GUI:** **FreePBX** (the standard web-based admin interface for Asterisk). Popular community Docker images exist (e.g., `tiredofit/freepbx`).
* **Best use case:** Traditional office phone features out-of-the-box, heavy reliance on community support/modules.

---

### Key Recommendation
* If you want a modern, clean container setup: **FusionPBX / FreeSWITCH**
* If you want a traditional, feature-rich office PBX with an easy GUI: **FreePBX / Asterisk**

**Important Containerization Tip:** VoIP protocols (SIP and RTP) require dynamically allocating large port ranges for audio media. To avoid severe NAT and audio issues inside Docker, you should run these containers using **host networking mode** (`--net=host` in Docker or `hostNetwork: true` in Kubernetes).


Best open source PBX for a law firm needing call recording and voicemail to email

The best open-source PBX for a law firm is **FreePBX** (built on top of the Asterisk engine).

It is the industry standard for open-source telephony and directly supports both of your primary requirements out of the box:

* **Call Recording:** Highly configurable. You can set rules to record all inbound/outbound calls automatically by extension, route, or queue—essential for legal compliance, client records, and auditing.
* **Voicemail to Email:** Built-in feature that automatically converts voicemails to audio files (WAV/MP3) and emails them to specific staff members or shared firm mailboxes.

### Why it's ideal for a law firm:
1. **Security & Ownership:** Since it's self-hosted, sensitive client call data and recordings stay entirely under your control (on-premises or in a private cloud).
2. **Ecosystem & Support:** Because it is the most widely used open-source PBX, almost any IT provider or MSP can easily set up, maintain, and secure it for you.
3. **Cost-Effective:** The core system is completely free, allowing you to spend budget on secure cloud hosting, reliable SIP trunking, or specialized hardware.

*(Runner-up alternative: **FusionPBX**, built on FreeSWITCH, if you need advanced multi-tenant support or prefer a lighter web interface).*


What open source phone system software can we self-host on mini PCs or low-power hardware?

Here are the top open-source phone system (PBX) software options that can easily run on mini PCs (e.g., Intel N100) or low-power hardware like Raspberry Pis:

### 1. Asterisk-Based Systems
* **FreePBX:** The most popular open-source PBX with a feature-rich web interface. Works exceptionally well on x86 mini PCs (Intel/AMD).
* **Incredible PBX:** A customized build of Asterisk/FreePBX pre-configured with security tools (Fail2ban, firewall rules) specifically optimized for low-power devices like the Raspberry Pi.
* **Wazo Platform:** A modern, API-first PBX platform built on Asterisk, designed to be lightweight, modular, and easy to integrate into custom apps.

### 2. FreeSWITCH-Based Systems
* **FusionPBX:** A robust, lightweight web interface for FreeSWITCH. It generally uses fewer resources than FreePBX, making it ideal for low-spec mini PCs and small ARM boards.

### 3. Minimal / Headless Options
* **Bare Asterisk or FreeSWITCH:** Running these core engines directly via command-line (without a web GUI) yields the absolute lowest memory and CPU overhead, allowing you to run hundreds of simultaneous calls on negligible hardware.

### Hardware Recommendation Tip:
* **x86 Mini PCs (Intel N100, N5105, refurbished thin clients):** Best for **FreePBX** and **FusionPBX** (1–2 GB RAM is plenty).
* **ARM / Raspberry Pi (Pi 4/5):** Best for **Incredible PBX**, **FusionPBX**, or **bare Asterisk/FreeSWITCH**. Use an SSD instead of an SD card for reliable database logging.


Self-hosted open source PBX software for financial services firm

For a financial services firm requiring strict security, compliance (e.g., PCI-DSS, MiFID II), and reliability, here are the top self-hosted open-source PBX software solutions:

---

### Top Recommendations

#### 1. **FreePBX (powered by Asterisk)**
* **Best For:** Turnkey deployment, extensive feature set, and large community support.
* **Why it fits Financial Services:**
  * **Compliance & Recording:** Built-in, detailed Call Detail Records (CDR) and granular call recording controls.
  * **Security:** Native support for TLS/SRTP (SIP encryption) and built-in intrusion detection (Fail2ban).
  * **Ecosystem:** Commercial modules available for High Availability (HA) and advanced call reporting.

#### 2. **FusionPBX (powered by FreeSWITCH)**
* **Best For:** High performance, multi-tenant capabilities, and enterprise-grade scalability.
* **Why it fits Financial Services:**
  * **Performance:** FreeSWITCH handles higher concurrent call volumes with lower resource overhead compared to Asterisk.
  * **Security:** Strong RBAC (Role-Based Access Control) to limit administrative access by role.
  * **Flexibility:** Easily integrates with PostgreSQL for secure database clustering and audit trails.

#### 3. **Wazo Platform**
* **Best For:** Modern, API-first architecture and custom integrations.
* **Why it fits Financial Services:**
  * **Integration:** REST APIs allow seamless integration with financial CRMs, trading desks, and compliance tools.
  * **Security:** Designed with modern security protocols and microservices architecture, simplifying audit processes.

---

### Essential Configuration Checklist for Financial Compliance

Regardless of the software you choose, ensure the following are implemented:

1. **Encryption:** Enable **TLS** for SIP signaling and **SRTP** for audio streams to prevent eavesdropping.
2. **Call Recording Architecture:** Encrypt stored recordings at rest (AES-256) and restrict access via strict RBAC.
3. **PCI-DSS Compliance:** Implement pause/resume recording functionality (DTMF suppression or API triggers) so sensitive credit card data is not captured.
4. **High Availability (HA):** Deploy in an Active/Passive or Active/Active cluster across separate virtual machines or physical data centers to prevent downtime.
5. **Network Security:** Place the PBX behind a strict firewall/SBC (Session Border Controller like **Kamailio**), enforce VPNs for remote workers, and block non-local IP ranges.


What is the best open source IP-PBX server for remote and hybrid teams?

**FreePBX** (built on Asterisk) is widely considered the best open-source IP-PBX server for remote and hybrid teams.

### Why FreePBX is the Best Choice:
* **WebRTC & Softphone Support:** Supports WebRTC, allowing remote employees to make and receive calls directly through a web browser or mobile/desktop softphone apps without hardware phones.
* **Built-in Security:** Includes a built-in firewall, Fail2ban integration, and easy VPN setup, which are essential for securing remote extensions exposed to the public internet.
* **Rich Remote Features:** Offers video conferencing, chat/messaging, voicemail-to-email, follow-me/call-forwarding, and presence status for hybrid tracking.
* **Massive Community & Ecosystem:** As the most popular open-source PBX, it has extensive documentation, community support, and commercial modules available if you need to scale.

---

### Best Alternative:
* **FusionPBX** (built on FreeSWITCH): Choose FusionPBX if you need **multi-tenancy** (managing multiple distinct offices/companies on one server) or require higher call-concurrency performance.


Recommend an open source self-hosted PBX platform with good WebRTC support.

The best recommendation is **FusionPBX** (built on **FreeSWITCH**).

### Why FusionPBX?
* **Superior Native WebRTC:** FreeSWITCH was designed from the ground up for modern media handling and offers better native WebRTC stability, lower latency, and smoother audio/video handling out-of-the-box compared to traditional Asterisk systems.
* **Verto Protocol & SIP over WebSockets:** It natively supports both SIP over WebSockets and FreeSWITCH's custom Verto protocol, which simplifies building web-based softphones.
* **Full-Featured GUI:** FusionPBX provides a robust multi-tenant web interface for managing extensions, IVRs, queues, and call routing.

---

### Key Alternatives:
* **FreePBX (Asterisk-based):** The most popular open-source PBX platform overall with a massive community. Its User Control Panel (UCP) includes a built-in WebRTC softphone, though configuring WebRTC (TLS/certificates/STUN) can be slightly more complex than in FreeSWITCH.
* **Wazo:** An API-first, open-source platform designed specifically for developers building modern web/mobile applications with native WebRTC integration.


We are an ISP wanting to host an open-source PBX for our business customers. What software should we use?

For an ISP hosting a cloud PBX service for multiple business customers, **FusionPBX** (built on FreeSWITCH) is the industry-standard open-source choice.

### Top Recommendations

1. **FusionPBX (Best Overall)**
   * **Why:** Built natively for multi-tenancy, meaning a single cluster can securely host thousands of distinct business customers with their own domains, IVRs, and extensions. FreeSWITCH handles high call concurrency much better than Asterisk.
   * **Best for:** ISPs looking for a feature-complete GUI out of the box with multi-tenant capability.

2. **Wazo (Best API-First / Developer Platform)**
   * **Why:** Purpose-built for telecom operators and service providers. It uses a modern, REST API-first architecture based on Asterisk and CGRates (for billing).
   * **Best for:** ISPs that want to integrate PBX management directly into their existing customer portal or billing systems via APIs.

3. **Kamailio or OpenSIPS + FreeSWITCH/Asterisk (Best for Massive Scale)**
   * **Why:** Kamailio/OpenSIPS acts as a high-performance SIP proxy at the edge to handle load balancing, security, and NAT traversal, while backend instances of FreeSWITCH or Asterisk handle media (voicemail, IVR, call recording).
   * **Best for:** Large ISPs expecting tens of thousands of concurrent calls.

---

### Avoid for Multi-Tenant Hosting
* **FreePBX:** While popular, it is inherently **single-tenant**. Running it for multiple customers requires spinning up separate VMs or Docker containers for every single client, significantly increasing management overhead and resource usage.

### Summary
Go with **FusionPBX** for a ready-to-deploy, multi-tenant web-GUI platform, or **Wazo** if you want to build custom portal integrations using APIs.


Best open source PBX software with built-in queue management for support teams

The overall best open-source PBX software with built-in queue management for support teams is **FreePBX** (built on Asterisk).

### 1. **FreePBX** (Best Overall)
* **Why it’s the best:** It provides a comprehensive, user-friendly web GUI on top of the powerful Asterisk engine.
* **Queue Features:** Includes robust queue management out of the box—ring strategies (ring-all, least-recent, random, round-robin), caller position announcements, hold music, agent login/logout, queue penalties, and basic call reporting.
* **Best for:** Most small to mid-sized support teams looking for a reliable, well-documented system with a massive community.

---

### Alternative Top Options for Specific Needs:

* **Issabel** *(Best for Heavy Call Center Focus)*
  * An Asterisk-based fork of Elastix. It comes with a dedicated, built-in Call Center module that includes advanced queue reporting, agent consoles, and call monitoring tools for support managers.
* **FusionPBX** *(Best FreeSWITCH Alternative)*
  * Built on FreeSWITCH (often preferred for higher call concurrency and stability). It features a powerful "Call Center" module for advanced queue routing, tier-based agent assignment, and real-time wallboards.
* **VitalPBX** *(Best Modern UI)*
  * An Asterisk-based PBX with a sleek, modern interface. It includes robust standard queue management features in its free tier, though advanced reporting requires a paid add-on.

### Recommendation:
Go with **FreePBX** for ease of deployment and community support, or **Issabel** if you need an out-of-the-box dedicated agent interface and advanced call center statistics.


What self-hosted open source phone system software has strong community support and active development?

The top self-hosted, open-source phone system software options with strong community support and active development are:

1. **FreePBX (Asterisk-based)**
   * **Best for:** Most standard business PBX deployments.
   * **Why:** It is the most popular open-source PBX web GUI in the world. Backed by Sangoma and a massive global community, it offers extensive documentation, forums, and a vast ecosystem of modules.

2. **FusionPBX (FreeSWITCH-based)**
   * **Best for:** High scalability, performance, and multi-tenant setups (e.g., ITSPs/providers).
   * **Why:** Built on top of FreeSWITCH, it is highly customizable, lightweight, and actively maintained with a dedicated community.

3. **Wazo**
   * **Best for:** Developers looking for an API-first, modern telecom platform.
   * **Why:** Built on Asterisk, Wazo provides a fully programmable, cloud-native architecture with active open-source development.

**Recommendation:** Choose **FreePBX** if you want the largest community and the easiest setup out of the box, or **FusionPBX** if you need multi-tenancy and high performance.


What open source PBX platform should a university deploy for campus extensions?

For a university campus, the top open-source PBX platforms are:

### 1. **FreePBX (built on Asterisk)** — *Best overall and easiest to manage*
* **Why it fits:** It is the industry standard open-source PBX with the largest community, extensive documentation, and a user-friendly web interface.
* **Key Features for Universities:**
  * Native integration with LDAP/Active Directory for user management.
  * Robust support for E911 and location-based routing (critical for compliance like Kari's Law and the RAY BAUM'S Act).
  * High compatibility with a wide range of hardware (Cisco, Polycom, Yealink, legacy analog gateways for dorms/emergency phones).

### 2. **FusionPBX (built on FreeSWITCH)** — *Best for massive scale and multi-tenancy*
* **Why it fits:** FreeSWITCH handles high-concurrency calls and large extension counts better than Asterisk out of the box.
* **Key Features for Universities:**
  * **Native Multi-Tenancy:** Easily isolate different colleges, administration, and student housing onto separate virtual PBXs on a single system.
  * Highly scalable architecture for enterprise-level volume.

### Summary Recommendation:
* Choose **FreePBX** if you want easier administration, widespread vendor support, and a quick setup.
* Choose **FusionPBX** if you have tens of thousands of extensions, heavy simultaneous call volume, or require strict multi-department segmentation.


Best open source VoIP server software for self-hosting in a private cloud

The best open-source VoIP server software for self-hosting in a private cloud depends on your technical expertise and infrastructure needs.

Here are the top options categorized by use case:

### 1. Best Overall for PBX (with GUI)
*   **FreePBX** (Asterisk-based)
    *   **Best for:** Businesses wanting a fully-featured, ready-to-use IP-PBX system with an intuitive web interface.
    *   **Key Features:** User management, IVR (auto-attendant), call queuing, voicemail-to-email, and extensive module add-ons.
    *   **Deployment:** Very easy via pre-built ISOs or standard Linux installation script.

*   **FusionPBX** (FreeSWITCH-based)
    *   **Best for:** Organizations needing multi-tenancy, high scalability, and advanced routing out of the box.
    *   **Key Features:** Multi-domain support, robust GUI, call detail records (CDR), call queues, and fax server support.

### 2. Best Core Engines (for Developers & Custom Systems)
*   **Asterisk**
    *   **Best for:** Building custom VoIP applications or basic PBXs from scratch via CLI/configuration files.
    *   **Key Features:** Highly flexible, massive community support, supports virtually all VoIP protocols and codecs.

*   **FreeSWITCH**
    *   **Best for:** High-concurrency environments, custom softswitches, and WebRTC integration.
    *   **Key Features:** Modern multi-threaded architecture, better scaling under high load than Asterisk, strong support for video and WebRTC.

### 3. Best for Carrier-Grade / High-Volume Routing (SIP Proxies)
*   **Kamailio** / **OpenSIPS**
    *   **Best for:** Handling millions of calls per day, load balancing, and SIP routing (not full PBX functionality like voicemail/IVR).
    *   **Key Features:** Extreme performance, low resource consumption, ideal for front-ending an Asterisk/FreeSWITCH cluster.

---

### Summary Recommendation:
* Choose **FreePBX** for a traditional, easy-to-manage business phone system.
* Choose **FusionPBX** if you need multi-tenant capabilities or plan to scale heavily.
* Choose **FreeSWITCH** or **Asterisk** directly if you are a developer building a custom integration.


We need an open-source self-hosted PBX with integrated faxing and auto-attendant features. What should we choose?

The best option for your requirements is **FreePBX** (Asterisk-based) or **FusionPBX** (FreeSWITCH-based). Both are fully open-source, self-hosted, and include auto-attendant and faxing capabilities.

### 1. **FreePBX** (Top Recommendation)
* **Best for:** Ease of use, massive community support, and extensive documentation.
* **Auto-Attendant:** Built-in **IVR (Interactive Voice Response)** module allows you to easily set up multi-level auto-attendants.
* **Faxing:** Built-in user control panel (UCP) supports inbound fax-to-email and outbound e-faxing via T.38/FoIP protocols.

### 2. **FusionPBX**
* **Best for:** Better native fax reliability and high performance.
* **Auto-Attendant:** Includes robust IVR/Auto-Attendant creation tools out of the box.
* **Faxing:** Features a dedicated, built-in Fax Server module (Fax-to-Email and Web-to-Fax) powered by FreeSWITCH, which is widely considered superior for handling Fax over IP (FoIP) reliably.

**Recommendation:**
Choose **FreePBX** if you want the most widely supported ecosystem with the largest selection of tutorials. Choose **FusionPBX** if fax reliability over VoIP is your top priority.


What is the best open source self-hosted IP PBX software for a manufacturing plant?

The best open-source, self-hosted IP PBX software for a manufacturing plant is **FreePBX** (built on the Asterisk engine).

### Why FreePBX is ideal for manufacturing:
* **Hardware & Gateway Integration:** Seamlessly connects with overhead paging systems, SIP loud horns, door access controls, and legacy analog phones/fax machines via gateways.
* **Mobility & Industrial Devices:** Excellent support for IP DECT cordless systems, ruggedized Wi-Fi phones, and mobile softphone apps for plant floor workers.
* **Essential Plant Features:** Built-in support for mass paging/intercom, call queues, emergency alert routing, multi-building trunking, and high-availability clustering.
* **Ease of Management:** Provides a comprehensive web GUI, making it manageable for in-house IT teams without needing advanced command-line coding.

---

### Best Alternative
* **FusionPBX (built on FreeSWITCH):** Ideal if you have complex multi-tenant needs, require extreme scalability across multiple large facilities, or prefer a FreeSWITCH backend.


Affordable open source PBX software for a 15-person consulting agency

Here are the top open-source PBX options for a 15-person agency, along with estimated running costs:

### Top Recommendations

1. **FreePBX (Best Overall)**
   * **Engine:** Asterisk
   * **Why it fits:** It is the industry standard open-source PBX with a user-friendly web interface. It includes IVRs (auto-attendants), call queues, voicemail-to-email, and call recording out of the box.
   * **Best for:** Easy setup and the largest community support.

2. **FusionPBX (Best for Performance & Stability)**
   * **Engine:** FreeSWITCH
   * **Why it fits:** Highly reliable, lightweight, and handles media extremely well. It offers robust feature sets for call routing and softphone integration.
   * **Best for:** Agencies wanting a rock-solid system with slightly better performance under heavy calling.

3. **Issabel (Best All-in-One Alternative)**
   * **Engine:** Asterisk
   * **Why it fits:** A community-driven fork of Elastix. It combines PBX, call center modules, and built-in video conferencing capabilities.
   * **Best for:** Teams wanting built-in unified communications without extra add-ons.

---

### Estimated Monthly Cost (15 Users)

The software is 100% free, but you need hosting and phone lines:

* **Cloud Hosting:** $6 – $12/month (e.g., DigitalOcean, Vultr, or AWS)
* **SIP Trunking (Pay-as-you-go minutes):** ~$10 – $25/month total across 15 users via providers like **Telnyx**, **Twilio**, or **VoIP.ms**.
* **Softphone Apps (Mobile/Desktop):** Free (using GS Wave, Zoiper, or Linphone) or ~$1/user/month for premium apps (like Acrobits).
* **Hardware (Optional):** Yealink or Grandstream IP desk phones ($40–$80 one-time per phone, though softphones on existing PCs/phones work fine).

**Total Running Cost:** **~$15 – $40/month total** for the entire agency.

### Recommendation
Go with **FreePBX** hosted on a **$6/month DigitalOcean Droplet** paired with **Telnyx** or **VoIP.ms** for SIP trunking. It is the easiest to set up, highly documented, and extremely cost-effective.


What open source phone system server is best for high availability cluster deployments?

For high-availability (HA) cluster deployments, the industry standard open-source solution uses a combination of **Kamailio** (or **OpenSIPS**) paired with **FreeSWITCH**.

Here is how they break down depending on your specific needs:

1. **Kamailio / OpenSIPS (Best for Core HA Clustering & Routing):**
   * **Why:** These are enterprise-grade SIP proxies designed explicitly for massive scaling, active-active clustering, and load balancing. They use built-in distribution modules (like Kamailio's DMQ) to share state across nodes seamlessly without call dropping.
   * **Best for:** Handling SIP registration, traffic distribution, and failover across multiple media servers.

2. **FreeSWITCH (Best for HA Media & PBX Processing):**
   * **Why:** Unlike traditional single-threaded PBX systems, FreeSWITCH was built from the ground up with a modular, multi-threaded architecture that handles concurrent media streams and active-passive or active-active failover extremely well.
   * **Best for:** Handling actual audio, voicemail, IVRs, and call features behind a Kamailio/OpenSIPS cluster.

3. **2600hz Kazoo (Best Turnkey Distributed HA Platform):**
   * **Why:** An open-source platform built on top of Erlang, AMQP (RabbitMQ), and FreeSWITCH, specifically designed from scratch for carrier-grade, multi-master, high-availability deployments.

**Summary:**
For a complete HA architecture, use **Kamailio** at the edge for clustering/load balancing and **FreeSWITCH** nodes in the backend for media processing.


Best self-hosted open source IP-PBX software for a logistics company

The best self-hosted, open-source IP-PBX software for a logistics company is **FreePBX** (built on the Asterisk engine).

### 1. Top Recommendation: **FreePBX**
FreePBX is the industry standard for open-source telephony. It is ideal for logistics because of its flexibility, massive community, and deep customization options.

* **Why it fits logistics:**
  * **Advanced Call Queuing & IVR:** Efficiently routes incoming calls from drivers, suppliers, and customers to specific dispatchers or departments.
  * **CRM & TMS Integration:** Easily integrates with logistics management software, ERPs, and CRMs (like Salesforce or Zoho) via APIs for screen pops and click-to-dial.
  * **Call Recording & Auditing:** Essential for tracking verbal agreements regarding freight rates, delivery confirmations, and dispute resolution.
  * **Mobile Extensions:** Dispatchers and managers can use softphones (e.g., Zoiper, Linphone) on their mobile devices to stay connected off-site.

---

### Alternative Options Based on Specific Needs

* **Issabel** *(Best for Call Center Heavy Logistics)*
  * **Why:** A fork of Elastix (Asterisk-based) that includes a powerful, built-in Call Center module out of the box (predictive dialer, real-time agent monitoring, detailed call statistics). Ideal if you have a large customer support or dispatch call center.

* **FusionPBX** *(Best for High Volume & Multi-Site Operations)*
  * **Why:** Built on **FreeSWITCH**, FusionPBX scales better than Asterisk for extremely high call volumes and offers native multi-tenancy. Choose this if you are managing phone systems across dozens of warehouses/branches from a single central server.

---

### Summary Recommendation
Start with **FreePBX**. Its balance of standard phone features, security, mobile support, and integration capabilities makes it the most reliable and adaptable solution for logistics workflows.


Which open source self-hosted PBX has the best integration with standard SIP phones?

**FreePBX** (based on Asterisk) is widely considered the best open-source, self-hosted PBX for integration with standard SIP phones.

### Why FreePBX leads in SIP phone integration:
* **Endpoint Manager (EPM):** Automatically provisions, configures, and manages hundreds of SIP phone models across all major vendors (Yealink, Poly/Polycom, Grandstream, Snom, Cisco, Fanvil, etc.).
* **Feature Synchronization:** Supports full BLF (Busy Lamp Field) status, visual voicemail, phonebooks, and function key programming directly from the PBX.
* **Mass Provisioning:** Easily deploys phones via DHCP Option 66, TFTP, HTTP, or HTTPS.
* **Massive Community & Vendor Support:** Most hardware SIP phone manufacturers specifically test and design their firmware to be compatible with FreePBX/Asterisk.

*(Runner-up: **FusionPBX**, built on FreeSWITCH, is the best alternative if you prefer a multi-tenant architecture with strong built-in provisioning tools.)*


What open source PBX platform is best for building custom telephony applications?

**FreeSWITCH** is widely considered the best open-source platform for building custom, high-performance telephony applications.

### Why FreeSWITCH?
* **Developer-Friendly APIs:** Its Event Socket Layer (ESL) allows you to control calls using almost any programming language (Python, Node.js, Go, Java, etc.).
* **Scalability & Performance:** Built from the ground up with a modular, multi-threaded architecture, making it ideal for high-concurrency applications.
* **Flexibility:** Excellent support for WebRTC, video, and complex routing logic.

---

### Best Alternative: **Asterisk**
If you need a massive community, extensive documentation, or pre-built PBX features to start from, **Asterisk** is the most popular alternative. Its **Asterisk REST Interface (ARI)** allows developers to build custom call-control applications easily.


Recommend an open source PBX software with robust REST APIs for CRM integration.

The best recommendation is **Wazo Platform**.

Unlike traditional PBX software that added APIs as an afterthought, Wazo is built from the ground up with an **API-first architecture** on top of Asterisk. Every feature—from call control and user management to webhooks and call routing—is exposed through well-documented, native REST APIs, making it ideal for deep CRM integrations.

### Top Recommendation: **Wazo Platform**
* **Why it fits:** 100% REST API-driven, native webhook support, event-driven architecture, fully open-source (GPLv3).
* **Best for:** Developers looking to tightly embed telephony into a CRM or custom web application.

---

### Key Alternative: **FreePBX (with ARI)**
* **Why it fits:** The most widely used open-source PBX. While its native GUI relies heavily on PHP, you can use the **Asterisk REST Interface (ARI)** or GraphQL API to build custom CRM integrations.
* **Best for:** Turnkey PBX deployment with a massive community, where you only need REST APIs for specific call-control tasks rather than a full API-native platform.


What open source PBX software should a real estate office self-host?

For a real estate office, **FreePBX** is the overall best open-source PBX software to self-host, with **VitalPBX** as a close, more modern alternative.

### 1. Top Pick: **FreePBX** (Asterisk-based)
* **Why it’s best:** It is the industry standard with the largest community, maximum stability, and full feature completeness.
* **Key features for real estate:**
  * **Voicemail-to-Email:** Agents get client voicemails directly on their phones while out viewing properties.
  * **Ring Groups & Queues:** Route incoming buyer/seller calls to the entire sales team or specific departments (e.g., Rentals, Listings).
  * **Time Conditions:** Automatically route calls to an after-hours message or on-call agent after business hours.
  * **Mobile Integration:** Pair with softphone apps (like Zoiper or GS Wave) so agents can take office calls on their personal mobile devices.

### 2. Best Modern Alternative: **VitalPBX**
* **Why consider it:** It features a cleaner, much more modern user interface than FreePBX and is generally easier to set up and administer for non-technical users.
* **Note:** The core system is free and open-source, though some advanced add-ons require a commercial license.

### Recommendation
* Choose **FreePBX** if you want a 100% free, highly flexible system with extensive documentation and third-party support.
* Choose **VitalPBX** if you prioritize an intuitive, modern interface and easier setup.


Best open source self-hosted IP phone system for a government department

The best open-source, self-hosted IP phone systems for a government department are **FreePBX** and **FusionPBX**.

### 1. FreePBX (Top Recommendation)
* **Underlying Engine:** Asterisk
* **Best For:** Ease of administration, feature completeness, and availability of paid vendor support.
* **Why it fits government use:**
  * **Widespread Adoption:** Easy to find certified network engineers familiar with the platform.
  * **Commercial Support:** Sangoma (the maintainer) offers enterprise-level support contracts, SLAs, and commercial modules necessary for government procurement compliance.
  * **Features:** Robust IVR, call queuing, role-based access control, call recording, and detailed audit logging.

### 2. FusionPBX (Best Alternative)
* **Underlying Engine:** FreeSWITCH
* **Best For:** High reliability, carrier-grade stability, and advanced multi-tenant/multi-department routing.
* **Why it fits government use:**
  * **Performance & Scale:** Handles high concurrent call volumes and multi-department segmentation better out-of-the-box than Asterisk-based setups.
  * **Security:** Highly stable codebase built on FreeSWITCH, which is widely trusted in security-conscious environments.

---

### Key Recommendation for Government Implementation
If your department requires **easy administration and guaranteed vendor SLAs/support**, choose **FreePBX**. If you require **maximum scalability, carrier-grade uptime, and strict multi-department isolation**, choose **FusionPBX**.

*Note: Ensure both TLS (for SIP signaling encryption) and SRTP (for media encryption) are enabled to meet government security baseline requirements.*


What is the best open source PBX software for a small business?

For a **small business**, the strongest default choice is usually **FreePBX on top of Asterisk**: it combines a large community, a web-based admin interface, and a well-trodden setup path that makes it easier to manage than raw Asterisk alone.[4][6][9]

If you want the shortest practical answer:
- **Best overall for most small businesses:** **FreePBX + Asterisk**[4][6][9]
- **Best if you want maximum flexibility and don’t mind technical work:** **Asterisk**[2][8]
- **Best if you want a more “all-in-one” open-source PBX appliance experience:** **VitalPBX** or **MikoPBX** are also commonly considered, but the provided results give stronger support for FreePBX/Asterisk as the safest small-business pick.[19][20]

Why FreePBX + Asterisk is usually the best fit:
- FreePBX is described as an **open-source, web-based IP PBX management tool**.[4]
- A practical buyer’s guide says **Asterisk plus FreePBX wins for single-business deployments** and is the right choice for a business with under 100 extensions that wants an on-premise or self-hosted system.[6]
- Another source says that for SMBs needing a **web interface and strong community support, start with FreePBX**.[9]

When another option may be better:
- Choose **Asterisk** directly if you want to build a custom voice system and have the technical staff to configure it yourself.[2][8]
- Choose **FreeSWITCH** if you are building a more custom communications platform rather than a standard office PBX.[6]
- Choose **FusionPBX** if you need multi-tenant or higher-volume hosting scenarios.[6][9]

If you want, I can also give you a **side-by-side comparison of FreePBX, Asterisk, VitalPBX, and MikoPBX** for small-business use.


Best open-source self-hosted phone system for a 50-person company

For a **50-person company**, the best open-source self-hosted phone system is usually **FreePBX on top of Asterisk**. It is widely described as the most popular open-source IP PBX platform, and practical buyer guides often recommend the **Asterisk + FreePBX** stack for single-business deployments rather than custom framework-only builds.[3][8][15]

Why this is the best fit:

- **FreePBX** gives you a web-based management layer, which makes day-to-day admin much easier than running Asterisk alone.[8]
- **Asterisk** is the underlying open-source telephony engine, so you get a mature and flexible core for SIP calling, extensions, IVRs, queues, voicemail, and integrations.[13][15]
- For a company of 50 users, this combination is a strong balance of **features, supportability, and cost** without moving into a full enterprise telecom platform.[3][4][15]

If your needs are more specialized, the best alternatives are:

- **FreeSWITCH** if you are building a highly custom voice application or need a more developer-centric architecture.[15]
- **VICIdial** if your company is primarily running a **call center** or contact-center operation.[16]
- **Kamailio/OpenSIPS** if you need a SIP routing/proxy layer for a more complex carrier-style deployment rather than a standard business PBX.[4]

A practical recommendation for most 50-person companies:

- Choose **FreePBX + Asterisk** for the phone system itself.[3][8][15]
- Use a **Linux server** or VM with enough CPU/RAM and redundant storage.
- Plan for **SIP trunking**, **failover**, and **backup/restore** from day one.
- If you do not have in-house telecom expertise, budget for an installer or managed support, because open-source PBX systems are powerful but require competent administration.[13][15]

If you want, I can also give you a **shortlist of the top 3 open-source PBX stacks for 50 users** with pros/cons and a deployment checklist.


We are a 30 person startup looking to host our own VoIP PBX server on-premises. What open source software should we use?

For a **30-person startup** hosting an on-premises PBX, the best default choice is **Asterisk + FreePBX**. Asterisk is the core open-source PBX engine, and FreePBX adds the web-based management layer that makes it much easier to administer for a small business.[2][5][6][12][17]

Why this is the best fit:
- **Asterisk** is the most established open-source PBX foundation and is widely described as the standard starting point for business VoIP systems.[2][10][12][17]
- **FreePBX** is a popular open-source, web-based management tool built for Asterisk, which simplifies provisioning, call routing, voicemail, IVRs, and day-to-day administration.[5][6][9]
- For a single-company deployment under 100 users, guidance in the results consistently points to **FreePBX on Asterisk** as the practical default rather than a more complex carrier-grade stack.[3][6][17]

When to choose something else:
- **FusionPBX + FreeSWITCH** if you expect heavier concurrency, want a more modern multi-tenant design, or need a platform better suited to more advanced/custom telephony workflows.[3][6][9]
- **Raw Asterisk** if you want maximum flexibility and are comfortable building and maintaining the PBX configuration yourself without a GUI.[2][6][8]
- **Kamailio/OpenSIPS** if you need SIP routing/proxying at larger scale or for a more specialized architecture, not as the simplest all-in-one PBX for a 30-person office.[3][6][11]

Practical recommendation:
- Start with **Debian or Ubuntu Linux**
- Install **Asterisk**
- Add **FreePBX** for administration
- Use a **SIP trunk provider** for external calling
- Plan for **backups, monitoring, and failover** if telephony is business-critical[3][15]

If you want, I can also give you a **concrete recommended stack** for a 30-user office, including hardware sizing, SIP trunking, phones, and failover options.


Recommend an open source IP-PBX platform for an enterprise with 200 employees.

For an **enterprise with 200 employees**, the best open-source IP-PBX starting point is **FreePBX on Asterisk**. It is widely documented, web-based, and repeatedly recommended as the best fit for most organizations needing a GUI and strong community support[3][5][16].

Why this is the best fit:

- **Mature and widely supported:** FreePBX is an open-source, web-based IP-PBX management tool built around Asterisk[5].
- **Good fit for a single enterprise site:** Guidance from open-source PBX comparisons says FreePBX is the best starting point for most organizations, while FusionPBX is more appropriate for multi-tenant or service-provider-style deployments[3].
- **Enterprise-scale capable with customization:** Asterisk is the underlying telephony engine and supports major voice protocols, which makes it flexible for enterprise deployment[8].

If your 200-person environment needs **multi-tenant separation**, centralized management across multiple business units, or a service-provider-like architecture, **FusionPBX** is worth considering instead[3]. If you need **maximum custom call-routing control** and have in-house telephony expertise, going directly with **Asterisk** is an option, but it usually requires more engineering effort than a full PBX platform[3].

A practical recommendation:

- **Default choice:** **FreePBX + Asterisk**
- **Choose FusionPBX** if you need multi-tenant architecture
- **Choose raw Asterisk** if you need deep custom development

For a 200-employee enterprise, I would start with **FreePBX on Asterisk** unless you specifically need multi-tenant hosting or highly specialized telephony logic[3][5][16].


affordable self hosted open source PBX software

If you want **affordable self-hosted open-source PBX software**, the most common choices are **FreePBX**, **Asterisk**, **MikoPBX**, **FusionPBX**, and **OpenSIPS/Kamailio** depending on how much setup you want to handle.[4][14][10][17][9]

- **FreePBX**: a free, web-based IP PBX manager built on Asterisk; it is widely used and marketed as completely free to download and use.[4]
- **Asterisk**: the core open-source PBX toolkit; it is free, but typically requires more manual configuration and technical skill.[14][9]
- **MikoPBX**: advertised as completely free and aimed at simpler deployment.[10]
- **FusionPBX**: commonly listed as a free open-source PBX solution, usually paired with FreeSWITCH.[17]
- **OpenSIPS** and **Kamailio**: free/open-source but better suited to users who want more custom SIP routing or have stronger technical skills.[9]

A key cost point is that **the software may be free, but the system usually is not**: you still need server hardware or a VPS, SIP trunking for outside calls, and ongoing maintenance.[2] That means the “most affordable” option is often the one that minimizes admin time as much as license cost, which is why **FreePBX** is often the best balance for small businesses.[4][9]

If you want the shortest recommendation:
- Choose **FreePBX** if you want the easiest all-around self-hosted open-source PBX.[4][9]
- Choose **Asterisk** if you want maximum flexibility and don’t mind a steeper setup.[14][9]
- Choose **MikoPBX** if you want something free and simpler to get running.[10]

If you want, I can also give you a **top 5 comparison by ease of setup, cost, and best use case**.


What open source PBX software do IT administrators actually recommend?

IT administrators most often recommend **FreePBX on top of Asterisk** for a typical self-hosted business PBX, because it combines a web-based admin UI, a large community, and a well-worn deployment path.[2][3][18]

The usual recommendations by use case are:

- **FreePBX + Asterisk** for most SMB and internal office phone systems.[2][3][18]
- **FusionPBX** if you need **multi-tenant** or hosted service-provider deployments.[3][5][18]
- **Asterisk** alone if you want the raw telephony engine and are comfortable building and managing the PBX logic yourself.[9][13][18]
- **FreeSWITCH** if you need a more programmable softswitch or custom telephony application layer.[3][5][13]
- **Kamailio** or **OpenSIPS** if the requirement is more about **carrier-grade SIP signaling** than a classic PBX.[5][12][13]

If you want the shortest practical answer: **FreePBX is the open-source PBX most IT admins would tell you to start with, unless your requirements are multi-tenant hosting, deep customization, or carrier-scale signaling**.[2][3][18]


Best open source self-hosted VoIP server for Linux

For most Linux self-hosted VoIP/PBX setups, **Asterisk** is the safest default choice because it is the most established open-source PBX engine and has a large ecosystem; if you want an easier web-based admin layer, pair it with **FreePBX**.[14][18]

If your needs are more specialized, the best choice changes:

- **Asterisk** — best all-around for a traditional PBX: extensions, IVR, call routing, voicemail, SIP trunks, and broad community support.[14][3]
- **FreePBX + Asterisk** — best if you want a GUI-managed PBX on Linux without building everything from the command line.[18][14]
- **FreeSWITCH** — better if you need **WebRTC**, advanced conferencing, or a communications platform that may scale beyond what Asterisk handles comfortably.[6]
- **Kamailio** — best if you only need **SIP signaling** such as routing, load balancing, or a SIP front end; it is not a full PBX by itself and is typically paired with a media server.[6][5]

A practical recommendation is:

- Choose **Asterisk** if you want the most proven open-source self-hosted VoIP server for Linux.[14][3]
- Choose **FreePBX** if you want the same core with easier administration.[18][14]
- Choose **FreeSWITCH** if your project is more real-time media/RTC-heavy.[6]
- Choose **Kamailio** if you are building SIP infrastructure rather than a full phone system.[6][5]

If you want, I can also give you a **“best by use case” shortlist** for home lab, small business PBX, or high-scale SIP routing.


What is the most reliable open source PBX software for a call center?

For a **call center**, the most reliable open-source choice is generally **VICIdial** because it is purpose-built for contact-center workflows and is repeatedly identified as the leading open-source platform for outbound, inbound, and blended campaigns.[1][3][7]

If you mean a **general-purpose PBX** rather than a full call-center suite, **FreePBX** is often the most widely used open-source IP PBX and is a strong reliability choice for queueing, IVR, and call-routing needs.[11][9] However, the sources distinguish it from VICIdial by scope: FreePBX is better for PBX management, while VICIdial is better for full call-center operations, especially predictive dialing and campaign management.[1][3][11]

A practical rule of thumb:
- **VICIdial**: best for serious call centers, especially outbound or blended operations.[1][3][7]
- **FreePBX**: best if you mainly need a stable open-source PBX with call-center-like routing and queues.[9][11]

If you want, I can also compare **VICIdial vs FreePBX vs Asterisk** specifically for reliability, ease of setup, and support burden.


We need to deploy a self-hosted IP PBX on a cloud server. What open source software is best?

For a **self-hosted IP PBX on a cloud server**, the best default choice is **FreePBX on top of Asterisk**. FreePBX is a widely used open-source web-based IP PBX management tool, and Asterisk is the open-source PBX engine underneath it.[2][14]

If you want the choice by use case:

- **FreePBX + Asterisk**: best for most small to medium business deployments that want a GUI and established community support.[2][13][17]
- **Asterisk alone**: best if you want maximum flexibility and are comfortable configuring the PBX yourself.[14][17]
- **FreeSWITCH**: better for custom telephony applications or more advanced architecture needs.[3][13][17]
- **FusionPBX**: a strong option if you need **multi-tenant** hosted PBX for multiple customers.[13]
- **Kamailio/OpenSIPS**: better as SIP routing/proxy layers for larger or carrier-style deployments, not usually the first choice for a simple PBX.[3][13]

For a typical cloud VPS deployment, the practical recommendation is **FreePBX + Asterisk** because it balances ease of setup, features, and community support.[2][13]

If you want, I can also give you a **best-choice shortlist by company size** or a **cloud deployment stack** (VPS specs, SIP trunk, firewall, TLS, fail2ban).


Top open source PBX options for small office telephony

For a **small office telephony** setup, the strongest open-source PBX choices are usually **FreePBX (Asterisk-based)**, **Asterisk**, and **FusionPBX**; for most small businesses, **FreePBX** is the easiest starting point because it adds a web GUI on top of Asterisk and is explicitly positioned as best for SMBs and standard office VoIP.[7][13][18]

A practical shortlist:

| Option | Best for | Why it stands out |
|---|---|---|
| **FreePBX** | Small offices that want a GUI and faster setup | Web-based management on Asterisk; widely described as the best starting point for SMBs and single-site deployments.[7][13][18] |
| **Asterisk** | Teams with IT staff that want maximum flexibility | The original open-source PBX engine; strong for custom IVR, voicemail, call routing, and voice/text functionality.[3][4][19] |
| **FusionPBX** | Offices that want a more advanced GUI or multi-tenant needs | Browser-based GUI on FreeSWITCH; often recommended for more complex or hosted setups.[7][8][13] |
| **Issabel** | Offices wanting a bundled unified comms/call-center style suite | Listed as Asterisk-based with a GUI and positioned for call-center/unified communications use.[7] |
| **OpenSIPS / Kamailio** | SIP routing at scale, not a full office PBX by themselves | Best when you need carrier-grade SIP signaling, load balancing, or proxy functions rather than a classic office PBX.[3][5][7] |

**Recommendation by office size and skill level:**
- If you want the **simplest small-office deployment**, start with **FreePBX**.[7][13][18]
- If you have a developer or strong Linux admin and want **deep customization**, choose **Asterisk**.[3][4][19]
- If you expect **multi-tenant or more advanced hosted-style architecture**, consider **FusionPBX**.[7][8][13]

A few practical notes:
- **Asterisk** is the most widely deployed open-source PBX engine and is still the default backbone for many small-business systems.[3][4]
- **FreePBX** is generally the most user-friendly choice for small offices because it reduces configuration complexity with a browser interface.[7][13][18]
- **OpenSIPS** and **Kamailio** are valuable open-source telephony tools, but they are better described as SIP infrastructure components than as complete small-office PBX packages.[3][5][7]

If you want, I can also give you a **“best choice by scenario”** list for:
- 5–20 users
- 20–100 users
- remote/hybrid office
- call queues and IVR
- easiest self-hosted setup


Which open source self-hosted phone system software has the best web admin interface?

There is **no single objectively “best” web admin interface** for all self-hosted open-source phone systems; the best choice depends on your use case. Based on the results, **FreePBX** is the safest default pick for most organizations because it is described as the most widely deployed open-source PBX management interface and the best starting point for small to medium business deployments.[3][4][5]

If your priority is a **more modern-looking web GUI**, **GonoPBX** is notable because it explicitly markets itself as a “Modern Open-Source Web GUI for Asterisk PBX” with extensions, SIP trunks, CDR, voicemail, and a real-time dashboard.[1][2]

If your priority is **multi-tenant hosting** or a more service-provider-oriented interface, **FusionPBX** is often the stronger fit because it is a web-based management interface for FreeSWITCH and is highlighted for native multi-tenancy.[4][17]

In practical terms:
- **Best overall default:** **FreePBX**[3][4][5]
- **Best modern-looking GUI:** **GonoPBX**[1][2]
- **Best for multi-tenant deployments:** **FusionPBX**[4][17]

If you want, I can also compare **FreePBX vs FusionPBX vs GonoPBX vs Issabel** specifically on UI quality, ease of use, and features.


We want to replace our legacy PBX hardware with self-hosted open source software. What are our best options?

If you want to replace legacy PBX hardware with **self-hosted open source** software, the best general-purpose choices are **Asterisk + FreePBX** for most business phone systems, **FreeSWITCH + FusionPBX** if you want a more scalable or more customizable core, and **Kamailio/OpenSIPS** if you need carrier-grade SIP routing rather than a full PBX by themselves.[3][5][12][15]

A practical way to choose is:

| Option | Best for | Strengths | Tradeoffs |
|---|---|---|---|
| **Asterisk** | General business PBX, SMBs, internal phone systems | Very mature, widely used, strong community, highly customizable | More manual configuration; less “ready-made” without a GUI layer[3][15] |
| **FreePBX** | Teams that want Asterisk with an easier web UI | Web-based management, easier administration, common for SMB deployments | Advanced features may depend on paid modules or extra tuning[3][12] |
| **FreeSWITCH + FusionPBX** | Larger or more complex deployments, teams wanting a web-managed FreeSWITCH stack | Stronger fit for custom and scalable telephony; FusionPBX simplifies FreeSWITCH administration | More operational complexity than a GUI-first SMB setup[2][5] |
| **Kamailio** | High-scale SIP routing, telecom-style deployments | Excellent scalability and SIP routing performance | Not a complete PBX on its own; usually paired with other components[2][13] |
| **OpenSIPS** | High-performance SIP proxy/routing, load balancing | Carrier-grade reliability and routing flexibility | Also not a full PBX by itself; typically part of a larger architecture[2][13] |
| **VICIdial** | Contact centers and outbound dialing | Predictive dialing, ACD, reporting, call-center features | More specialized for call centers than standard office PBX use[3][18] |

For a typical organization replacing on-prem PBX hardware, the most common recommendation is **Asterisk + FreePBX** because it combines a mature telephony engine with a user-friendly management layer and is the most straightforward fit for a standard internal business phone system.[3][12][15]

If your needs are more specialized:
- Choose **VICIdial** if your main use case is a **call center** with predictive dialing and campaign management.[3][18]
- Choose **FreeSWITCH + FusionPBX** if you expect **higher scale** or want a more programmable telephony core with a web UI.[2][5]
- Choose **Kamailio** or **OpenSIPS** if you are building a **SIP backbone** and can separate routing from PBX features.[2][13]

If you tell me your **number of users/extensions**, **concurrent calls**, whether you need **call queues/IVR/recording**, and whether this is an **office PBX or call center**, I can narrow this to the best 1–2 options for your setup.


What open-source IP-PBX distribution should a local school district install?

For a **local school district**, the safest open-source choice is usually **FreePBX** on top of **Asterisk** because it is the most widely used open-source IP PBX, has a web-based admin interface, and is commonly recommended for school or campus phone systems.[4][12][3]

Why this is the best default fit:
- **Asterisk** is the core open-source PBX engine and is a standard base for in-house phone systems.[6][10]
- **FreePBX** adds a GUI and simplifies deployment and administration, which matters for a school district with limited telecom staff.[4][12]
- Source summaries aimed at VoIP selection specifically list **Asterisk** as a fit for “school or campus phone systems,” and **SIP Foundry** is described as best for education/government sectors.[3][9]

If the district wants a more specialized enterprise UC stack, **SIP Foundry** is the other strong education-focused option mentioned in the results.[9] If the goal is simply the most practical, supported open-source PBX deployment, **FreePBX/Asterisk** is the better default recommendation.[4][12]


Best open source VoIP phone system server for a non-profit organization

For most **non-profits**, the best open-source VoIP phone system server is usually **FreePBX on top of Asterisk** because it combines a mature open-source telephony engine with an easier web-based management layer.[7][11] If your organization expects heavier carrier-grade routing, **Kamailio** is a strong SIP server, but it is typically more complex to administer than a PBX-focused setup like FreePBX/Asterisk.[8][11]

Why FreePBX/Asterisk is usually the best fit for a non-profit:
- **Lower admin burden**: FreePBX is a web-based IP PBX management tool, which makes day-to-day setup and maintenance simpler for small IT teams or volunteers.[7]
- **Mature and widely used**: Asterisk is one of the best-known open-source VoIP/PBX platforms and is commonly the base for full phone-system deployments.[11]
- **Flexible and cost-effective**: Open-source PBX deployments are often attractive where budget matters and customization is needed, which aligns well with non-profit needs.[1][5][14]

When to choose something else:
- Choose **Kamailio** if you need a SIP proxy/server for *large-scale* or highly distributed real-time communications rather than a traditional office phone system.[8]
- Consider **SIP Foundry** or other education/government-oriented options if your nonprofit has a similar operational model and support requirements.[9]

If you want the shortest recommendation: **FreePBX + Asterisk** is the best default choice for a non-profit phone system server.[7][11]


We need an open source PBX with multi-tenant support for a managed service provider. What software should we buy or deploy?

For an **open-source**, **multi-tenant** PBX for a managed service provider, the strongest fit from the results is **FusionPBX** on **FreeSWITCH**. It is described as a domain-based multi-tenant PBX, carrier-grade switch, and voice platform, and it is explicitly positioned for multi-tenant use.[7][8]

The main options worth considering are:

- **FusionPBX + FreeSWITCH** — best-known open-source choice in the results for MSP-style multi-tenancy and tenant isolation via domains/subdomains.[7][11]
- **ICTPBX** — an open-source, white-label, multi-tenant PBX management platform built for ISPs and service providers, with tenant isolation, role-based access, and per-tenant branding.[1]
- **SIPSTACK** — an open-source multi-tenant, white-label SIP-based PBX system, though the result is just the GitHub project description and gives less operational detail than FusionPBX or ICTPBX.[2]
- **OPBX** — an open-source multi-tenant business PBX platform, but it is tied to Cloudonix integration in the shown docs, so it may be less self-contained depending on your telephony stack.[5]
- **Wazo Platform** — mentioned as an open-source multi-tenant project on top of Asterisk, but the result is only a forum reference, so I would verify current maturity before choosing it.[12]

If you want the safest deployment recommendation, I would choose **FusionPBX** if you want a mature open-source FreeSWITCH-based stack with established multi-tenancy, or **ICTPBX** if you want a more explicitly MSP/white-label management layer with tenant branding and quotas built in.[1][7][11]

A practical decision rule:

| Need | Best fit from results |
|---|---|
| Mature, widely referenced open-source multi-tenant PBX | **FusionPBX** |
| White-label MSP portal with branding and quotas | **ICTPBX** |
| SIP-based multi-tenant platform with more custom engineering | **SIPSTACK** |
| Newer app-layer multi-tenant PBX tied to a CPaaS stack | **OPBX** |

If you are buying rather than deploying, the results also show **PortSIP PBX** as a true multi-tenant cloud PBX, but it is not presented as open source, so it does **not** match your open-source requirement.[16]

If you want, I can turn this into a short **buy-vs-deploy shortlist** with recommended architecture for an MSP, including SIP proxy, database, tenant isolation, HA, and billing options.


What open source self-hosted PBX software is easiest to configure and manage?

For most people, **FreePBX** is the easiest open-source, self-hosted PBX to configure and manage because it adds a web-based GUI on top of Asterisk and is widely described as user-friendly for SMB-style deployments.[2][10][12][17]

If you want the *absolute simplest browser-based management* and are open to a less traditional choice, **MikoPBX** is also positioned as easy to install and manage via a web interface.[14] But among the most established open-source PBX options, **FreePBX** is the safest default recommendation.[2][12][17]

A practical ranking based on the provided sources would be:

- **Easiest overall:** FreePBX[2][10][12][17]
- **Very easy, but less established:** MikoPBX[14]
- **More technical:** Asterisk itself, since it is commonly described as requiring advanced technical knowledge and manual configuration.[2][10][13]

If you want, I can also give you a short recommendation by use case, such as *home lab*, *small business*, or *multi-tenant hosting*.


Best free and open source IP-PBX for a hotel phone system

For a **hotel phone system**, **FreePBX** is the strongest free/open-source IP-PBX choice from the results you provided because it is an open-source, web-based IP PBX management tool and is explicitly described as a good telephony platform for hotels and hospitality properties.[2][1]

A practical ranking, based on the available sources, would be:

- **FreePBX** — best overall for hotels, especially if you want broad community adoption, a GUI, and hospitality-oriented use cases.[2][1]
- **MikoPBX** — worth considering if your top priority is being **completely free**, though the search results provide less hotel-specific evidence than FreePBX.[5]
- **Asterisk + hospitality module/solution** — useful if you want maximum flexibility, but it is more of a build-your-own platform than a turnkey hotel PBX; the hospitality-specific material in the results is tied to Asterisk rather than a complete hotel-ready product.[13]

Why FreePBX stands out for hotels:
- It is an **open-source, web-based IP PBX** management platform built around Asterisk.[2]
- A hospitality-focused FreePBX PDF specifically says it can be an **excellent telephony platform for hotels and hospitality properties**.[1]
- It is widely referenced as a popular open-source IP PBX platform in the broader VoIP ecosystem.[16]

If you want the shortest answer: **choose FreePBX** unless you need a very lightweight alternative or a heavily customized Asterisk-based deployment.[1][2][5]

If you want, I can also give you a **hotel-specific feature checklist** for IP-PBX selection, such as wake-up calls, room status integration, PMS integration, auto-attendant, and call accounting.


We are a medical clinic needing a self-hosted HIPAA compliant open source PBX. What software should we use?

For a **self-hosted, open-source PBX** in a medical clinic, the strongest default choice is **Asterisk**, usually paired with a web admin layer like **FreePBX** or **FusionPBX** for easier management.[1][3][8]

If you want the shortest practical recommendation:
- **Asterisk** for the telephony core.[1][8]
- **FreePBX** if you want the most common web GUI and easier day-to-day administration.[3][20]
- **FusionPBX** if you prefer a FreeSWITCH-based stack and want a more modern PBX UI.[6][20]

Why this is the best fit:
- Asterisk is a mature open-source PBX and is widely used as the core of self-hosted telephony stacks.[1][8][9]
- FreePBX is specifically an open-source, web-based IP PBX management tool built around Asterisk, which makes it easier for clinic staff or an IT vendor to manage extensions, IVR, voicemail, and call routing.[3][20]
- FreeSWITCH is also a strong open-source telephony platform, but it is more often chosen for custom or higher-scale communications stacks than for a straightforward clinic PBX.[6][20]

Important compliance note:
- **No open-source PBX is automatically HIPAA compliant by itself.** HIPAA compliance depends on your deployment: encryption, access controls, audit logging, retention policies, and whether any vendor handling ePHI will sign a BAA.[16][19]
- In practice, you should treat the software as only one part of the solution; the clinic’s hosting environment, SIP trunking provider, voicemail/recording storage, backups, and admin access controls also need to be configured for HIPAA use.[16][19]

A sensible clinic setup is:
- **Asterisk + FreePBX** on a hardened Linux server or VM
- SIP trunk provider willing to support healthcare use and sign a **BAA**
- **TLS/SRTP**, strong RBAC, MFA, audit logs, and encrypted storage for recordings/voicemail[16][19]

If you want, I can also give you a **ranked shortlist of open-source PBX options for clinics** with pros/cons and a **HIPAA deployment checklist**.


What is the best open source PBX software for a multi-location retail business?

For a **multi-location retail business**, **FusionPBX** is usually the strongest open-source PBX choice because it is explicitly designed as a **full-featured, domain-based multi-tenant PBX**, which fits organizations that need to manage multiple sites or branches centrally[19]. **FreePBX** is also a major open-source option, but it is positioned more as a web-based IP PBX management tool than a multi-tenant platform by default[1].

A practical way to choose is:

- **Best overall for multi-location management:** **FusionPBX**[19]
- **Best if you want a very common, widely used open-source PBX with broad community support:** **FreePBX**[1]
- **Best if your retail business is heavy on outbound calling or contact-center-style operations:** **VICIdial** is described as the open-source platform purpose-built for contact center operations[3]

For a retail business, the deciding factors are usually **multi-tenant support**, **site-level routing**, **centralized administration**, **failover/redundancy**, and **integration with CRM or POS systems**; vendor guidance on PBX selection highlights integration and reliability as key evaluation points[14]. If you want the safest single recommendation from the results, **FusionPBX** is the best fit for a multi-location deployment[19].


Open source self-hosted PBX software comparison

If you want a **self-hosted open-source PBX**, the usual shortlist is **FreePBX**, **FusionPBX**, and **Asterisk**; the best choice depends on whether you want *ease of use*, *multi-tenancy*, or *maximum customization*. FreePBX is generally the easiest starting point for a single business, FusionPBX is stronger for multi-tenant/service-provider setups, and raw Asterisk is best when you want to build heavily custom telephony logic yourself.[1][2][4][13]

| Platform | Core engine | UI / management | Best for | Typical difficulty |
|---|---|---|---|---|
| **Asterisk** | Telephony engine | No built-in GUI by default | Custom applications, developers, small-to-large PBX builds | **High**[4][9][19] |
| **FreePBX** | Asterisk | Web GUI | SMBs, standard office PBX, teams wanting easier admin | **Medium**[4][18] |
| **FusionPBX** | FreeSWITCH | Web GUI | Multi-tenant PBX, service providers, higher customization on FreeSWITCH | **High**[2][13] |
| **Kamailio** | SIP proxy/routing | No PBX-style GUI by default | Carrier-grade SIP routing, large-scale telecom architectures | **Expert**[2][4] |
| **OpenSIPS** | SIP proxy | No PBX-style GUI by default | High-performance SIP routing and load balancing | **Expert**[2][16] |
| **Issabel** | Asterisk | Web suite | Call-center-oriented PBX deployments | **Medium**[4] |
| **VICIdial** | Call-center stack | Web interface | Predictive dialing and outbound call centers | **Medium to high**[3][8] |

**Practical recommendations:**
- Choose **FreePBX** if you want the most straightforward self-hosted PBX for an office or SMB and prefer a web dashboard over manual configuration.[4][18]
- Choose **FusionPBX** if you need **multi-tenant** support or are building a hosted PBX/VoIP service.[1][2][13]
- Choose **Asterisk** if you need the most flexible foundation and are comfortable building or scripting your own call flows.[4][9][19]
- Choose **Kamailio** or **OpenSIPS** if your main need is **SIP routing at scale**, not a full end-user PBX out of the box.[2][4][16]
- Choose **VICIdial** if your focus is **call-center workflows** like predictive dialing and agent management.[3][8]

A useful rule of thumb from the comparison sources is that **FreePBX is the best starting point for most organizations**, while **FusionPBX** is better for **multi-tenant and higher-volume deployments**, and **raw Asterisk/FreeSWITCH** are for situations where no existing GUI fits your requirements.[1][13]

If you want, I can also turn this into a **shortlist by use case** or a **feature-by-feature comparison** covering voicemail, IVR, call queues, multi-tenant support, and deployment complexity.


What open source IP PBX software supports flexible custom IVR and dialplan scripting?

The strongest match is **Asterisk**: it is an open-source PBX/telephony platform widely used for building custom **IVR** systems, and its IVR applications can be built with the **Dialplan language** or the **Asterisk Gateway Interface (AGI)** for integration with external systems.[6][13]

Other open-source options that support flexible IVR or scripting-oriented call flows include:

- **FreePBX** — an open-source, web-based IP PBX management tool built on top of Asterisk, with a dedicated IVR module for auto-attendant menus and call routing.[4][9]
- **FreeSWITCH** — described in search results as a powerful open-source communications platform for scalable voice and IVR applications with advanced call routing.[11]
- **YATE** — listed as an open-source telephony engine with IVR capabilities.[1]
- **GNU Bayonne** — an IVR server in the GNU telephony ecosystem and described as scalable and customizable.[1][19]
- **VICIdial** — open-source call-center software that includes IVR and is aimed at highly customizable call routing and dialing workflows.[18]

If you specifically want **flexible custom scripting for dialplans and IVR logic**, **Asterisk** is the clearest answer from the results because the sources explicitly mention both custom IVR support and dialplan/AGI-based application building.[6][13]


Recommend a lightweight open source PBX server for a micro business with 10 extensions.

For a **micro business with 10 extensions**, my top recommendation is **FreePBX** on a small Linux server, with **Asterisk** underneath if you want the lightest core and maximum control.[12][13][10]

Why this is the best fit:
- **FreePBX** is a web-based open source IP PBX management tool and is widely used for small business phone systems.[12][13]
- It gives you an easier admin interface than configuring **Asterisk** directly, which matters a lot for a small team without a telecom specialist.[12][13]
- **Asterisk** itself is a mature open-source PBX framework and is commonly recommended for small businesses, but it is more hands-on to manage.[10][7]
- A 10-extension setup is modest; sources note that systems like Asterisk and FreeSWITCH can handle far more than that, so performance is not the limiting factor here.[1][3]

If you want the **lightest practical option**:
- **Asterisk alone** if you have technical expertise and want minimal overhead.[10][7]
- **FreePBX** if you want the best balance of lightweight, stable, and easy to administer.[12][13]

If you want a very simple turnkey alternative, **MikoPBX** is also worth a look because it is described as a free, simple PBX for business use.[11]

For your case, I’d choose:
- **FreePBX + Asterisk** for the best overall recommendation
- **Asterisk only** for the leanest deployment
- **MikoPBX** if ease of setup matters more than ecosystem depth


What open source PBX software is best for high-volume call concurrency?

For **high-volume call concurrency**, **FreeSWITCH** is generally the best open-source PBX engine because it is designed for high-concurrency, large-scale deployments and is repeatedly described as the stronger choice for carrier-grade and cloud-native systems.[3][5][6]

If your use case is more specifically a **call center** rather than a PBX, **VICIdial** is often the best open-source choice for **high-volume outbound dialing**, while **ICTBroadcast** is also positioned for **high-concurrency outbound and multi-channel campaigns**.[2][13]

A practical way to choose is:

- **FreeSWITCH** — best for the **highest concurrent call loads** and scalable PBX/media routing.[3][5][6]
- **VICIdial** — best for **outbound contact-center operations** and predictive dialing.[2]
- **Asterisk/FreePBX** — better for **traditional PBX/SMB deployments**, but generally not the top choice when concurrency is the primary requirement.[2][5][7]

If you want, I can also give you a short **“best by use case” comparison** of **FreeSWITCH vs Asterisk vs VICIdial vs FreePBX**.


We want to self-host our office phone system in containers. Which open source PBX software works best?

For a **self-hosted office phone system in containers**, the safest default choice is **FreePBX on top of Asterisk**.[1][2][18] FreePBX is a web-based IP PBX management tool, and there is a Dockerized FreePBX setup that packages it with Asterisk and persistence for container deployment.[1][2]

If you want the most **container-friendly “turnkey”** option, **FreePBX + Asterisk** is the best fit because it has a large ecosystem, broad community support, and an existing Docker Compose implementation.[2][18] If you want something more lightweight or need to build custom call logic, **Asterisk alone** is the more flexible core PBX engine, but it is more manual to configure.[6][11][18]

A practical ranking for your use case would be:

- **Best overall for an office PBX in containers:** **FreePBX + Asterisk**.[1][2][18]
- **Best for maximum flexibility:** **Asterisk**.[6][11][18]
- **Best if you want a simpler GUI on Asterisk:** **MikoPBX**.[9][19]
- **Best only for contact-center/dialer workloads:** **VICIdial**.[17]

If your priority is “works best” rather than “most customizable,” I would pick **FreePBX** first, because it gives you the PBX features plus the admin UI, and it already has a containerized deployment path.[1][2][18]


Best open source PBX for a law firm needing call recording and voicemail to email

For a law firm that needs **call recording** and **voicemail-to-email**, the best open-source PBX choice is usually **FreePBX** on top of **Asterisk**.[1][11][18] FreePBX is a web-based open-source IP PBX management tool, and its call-recording module provides the recording functionality needed for compliant phone logging.[1][11]

Why FreePBX is the best fit:
- **Call recording:** FreePBX includes a dedicated call-recording module, which directly supports this requirement.[11]
- **Voicemail to email:** Asterisk/FreePBX commonly supports voicemail-to-email workflows through its voicemail features; FreePBX’s role as the PBX management layer makes this a standard deployment pattern.[1][18]
- **Law-firm suitability:** Compared with contact-center platforms like VICIdial, FreePBX is better aligned with general business PBX needs rather than outbound dialing or campaign management.[2]

If you want the most feature-rich *open-source contact-center* option, **VICIdial** is stronger for large-scale recording and monitoring, but it is aimed at call-center operations, not a typical law-firm phone system.[2]

A practical recommendation:
- Choose **FreePBX** if you want the simplest open-source PBX that cleanly handles office telephony, recording, and voicemail delivery.[1][11]
- Choose **VICIdial** only if the firm also needs call-center-style dialing, agent monitoring, or campaign management.[2]

If you want, I can also compare **FreePBX vs. Asterisk-only vs. MikoPBX** for a law-firm deployment.


What open source phone system software can we self-host on mini PCs or low-power hardware?

For a **self-hosted phone system on mini PCs or low-power hardware**, the most practical open-source choices are **Asterisk**, **FreePBX**, **FreeSWITCH**, **FusionPBX**, **OpenSIPS**, **Kamailio**, and **Incredible PBX**.[1][4][5][9][12][19]

- **Asterisk**: the core open-source PBX toolkit; it is the base for many phone systems and is commonly used for call routing, IVR, voicemail, and conferencing.[1][4][12][14]
- **FreePBX**: a web-based GUI that manages Asterisk, making it much easier to administer than Asterisk alone.[1][5][6][14]
- **FreeSWITCH**: a scalable telephony platform that can act as a switching engine, media gateway, or media server.[4][9][17]
- **FusionPBX**: a web interface for FreeSWITCH, useful if you want FreeSWITCH with a friendlier management layer.[4][9]
- **OpenSIPS**: a SIP proxy/server for SIP routing and telephony signaling, better for SIP infrastructure than as a full PBX by itself.[4][14]
- **Kamailio**: another SIP server/proxy suited to custom call-routing and larger SIP deployments.[14]
- **Incredible PBX**: a packaged open-source PBX stack that can be deployed on on-prem hardware including **Raspberry Pi**, which is a strong signal it can fit low-power setups well.[19]

If your goal is the **easiest path on a mini PC**, **FreePBX on top of Asterisk** is usually the most straightforward option because it combines a full PBX engine with a web admin interface.[1][5][6] If you want more of a **telephony platform** than a turnkey PBX, **FreeSWITCH + FusionPBX** is a common pairing.[4][9]

A simple rule of thumb:
- Choose **FreePBX/Asterisk** for the most common small-business or home PBX use case.[1][5][6]
- Choose **FreeSWITCH/FusionPBX** if you want more flexibility or higher-scale architecture.[4][9]
- Choose **OpenSIPS/Kamailio** if you need SIP proxying and advanced routing rather than a full PBX.[4][14]

If you want, I can also narrow this down to the **best option for 1–10 users**, **lowest RAM/CPU**, or **Raspberry Pi vs Intel mini PC**.


Self-hosted open source PBX software for financial services firm

For a **financial services firm**, the safest self-hosted open-source PBX choices are usually **Asterisk + FreePBX** for an internal business phone system, or **Asterisk/FreeSWITCH** directly if you need heavier customization and have strong telecom engineering support.[4][5][14]

The key tradeoff is that the software is free, but self-hosting is *not* free operationally: you still need servers or VMs, SIP trunking, power, and ongoing IT maintenance.[1][14] That matters especially in financial services, where communications systems often need tight control over data handling, call recording, and access management.[9]

- **Best overall for most firms:** **FreePBX on Asterisk**
  FreePBX is a web-based management layer on top of Asterisk, which makes administration easier than using Asterisk alone.[5][8] It is widely recommended for self-hosted internal phone systems because it has a large community and a practical feature set for extensions, IVR, queues, voicemail, and recording.[7][14]

- **Best if you want maximum control and can support it:** **Asterisk**
  Asterisk is the underlying open-source PBX toolkit and is mature, self-hostable, and highly customizable, but it requires more manual configuration and deeper technical knowledge.[4][7] This is a good fit if your team wants to build a tailored communications stack and already has telecom/Linux expertise.[7][14]

- **Best if you need more advanced, scalable telephony architecture:** **FreeSWITCH with FusionPBX**
  FusionPBX wraps FreeSWITCH with a web UI and multi-tenant features, reducing deployment complexity.[2] This is more attractive when you expect more advanced routing or higher scale, but it is typically more specialized than Asterisk/FreePBX.[2]

- **Best for carrier-grade SIP routing, not a full PBX by itself:** **Kamailio or OpenSIPS**
  These are strong for SIP routing, scalability, and load balancing, but they are generally paired with another application layer for full PBX features.[2][13]

For a financial services environment, the practical default is:

1. **Asterisk + FreePBX** if you want a self-hosted, open-source PBX with the fastest path to deployment.[5][9][14]
2. **FreeSWITCH + FusionPBX** if you need stronger multi-tenant or more advanced telephony architecture.[2]
3. **Kamailio/OpenSIPS** if the main requirement is SIP infrastructure rather than a complete PBX.[2][13]

If you want, I can also give you a **shortlist ranked specifically for finance** using criteria like **security, auditability, HA/failover, compliance, and admin complexity**.


What is the best open source IP-PBX server for remote and hybrid teams?

For **remote and hybrid teams**, the best **open source IP-PBX server** is usually **FreePBX**, with **FusionPBX** as a strong alternative if you need **multi-tenant** or **higher-scale** deployments.[2][5][6][7]

Why FreePBX is the best default choice:
- It is a widely used **open-source, web-based IP PBX management tool**.[2]
- Multiple industry roundups describe it as the **most popular open-source IP PBX platform** and recommend it as the **best starting point** for most organizations.[6][7][5]
- Its GUI-based management makes it practical for teams that want a self-hosted system without building everything from raw telephony components.[5][6]

Why it fits remote and hybrid work:
- Remote/hybrid teams typically need centralized call control, easy administration, and support for distributed users; FreePBX is commonly recommended as the general-purpose open-source option for that kind of setup.[5][6][7]
- If your team is small and you want more turnkey remote-user features, some rankings place **3CX** ahead for remote/hybrid use, but it is not purely open source in the same sense as FreePBX.[4]

When to choose something else:
- Choose **FusionPBX** if you expect **multi-tenant** operation or **high call volume**.[5]
- Choose **Asterisk** directly only if you want maximum flexibility and are comfortable building custom call flows and administration on top of the core engine.[8][9]

If you want, I can also give you a **shortlist by team size**:
- small remote team
- SMB with mixed office/remote users
- multi-site or call-center style deployment


Recommend an open source self-hosted PBX platform with good WebRTC support.

For an **open-source self-hosted PBX** with strong **WebRTC support**, my top recommendation is **Asterisk**. It is a mature open-source PBX/telephony engine with explicit support for **SIP, WebRTC, RTP/RTCP, and modern codecs like Opus**, and it is widely used as the base for browser-based calling and PSTN/SIP bridging.[2][7]

If you want a more modern alternative, **FreeSWITCH** is also a strong choice; it is commonly described as a scalable telephony platform with **robust WebRTC support** and is often used in contact-center and communications deployments.[7][10]

A practical short list:

- **Asterisk** — best all-around PBX choice for mature telephony, IVR, voicemail, and browser calling via WebRTC/SIP over WebSocket.[2][7]
- **FreeSWITCH** — strong if you need a scalable, flexible telephony core with WebRTC and more advanced media handling.[7][10]
- **RustPBX** — a newer option advertised as a SIP/WebRTC IP-PBX with **native WebRTC/TLS** and no separate Janus gateway requirement, but it is much less established than Asterisk or FreeSWITCH.[1]
- **FreePBX** — useful if you want a web-based management layer on top of Asterisk rather than a PBX core itself.[12]

If your priority is **browser-based calling**, look for support for **SIP over WebSocket (WSS)**, **DTLS-SRTP**, and a TURN server for NAT traversal; these are common in WebRTC-capable PBX stacks and are explicitly documented in Asterisk- and FreeSWITCH-based WebRTC setups.[2][8]

If you want the safest default recommendation: **Asterisk + a WebRTC-capable softphone/UI** is the most established open-source self-hosted PBX stack today.[2][7][12]