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

Here are the best self-hosted, open-source PBX options, categorized by user needs:

### 1. **FreePBX (Asterisk-Based)** — *Best Overall for Standard Business*
* **Overview:** The most popular open-source PBX. It provides a user-friendly Web GUI on top of the powerful Asterisk communications engine.
* **Why choose it:** Huge community, extensive documentation, highly reliable, and easy to manage without deep command-line knowledge.
* **Best for:** Small-to-medium businesses wanting a traditional PBX replacement with modern VoIP features.

### 2. **FusionPBX (FreeSWITCH-Based)** — *Best for Scalability & Multi-Tenancy*
* **Overview:** A feature-rich Web GUI for **FreeSWITCH**, an alternative engine to Asterisk designed for high performance and concurrency.
* **Why choose it:** Supports multi-tenancy (run multiple sub-companies on one server) and handles high call volumes very efficiently.
* **Best for:** Enterprises, service providers, or environments with heavy call volumes.

### 3. **Issabel** — *Best Turnkey / Unified Communications*
* **Overview:** An open-source, community-driven continuation of Elastix (Asterisk-based).
* **Why choose it:** Offers an all-in-one platform out of the box, including PBX, call center modules, video conferencing, and built-in security tools (Fail2ban).
* **Best for:** Call centers and organizations needing integrated communications features without buying add-ons.

### 4. **Asterisk or FreeSWITCH (Vanilla/CLI)** — *Best for Developers*
* **Overview:** The underlying open-source engines without a GUI interface.
* **Why choose it:** Maximum control and customizability. You can build completely custom IVRs, CRM integrations, and routing logic using APIs (like Asterisk ARI).
* **Best for:** In-house development teams building custom telecom applications.

---

### Recommendation Summary:
* Choose **FreePBX** for the easiest setup and standard business features.
* Choose **FusionPBX** if you need high-scale performance or multi-company hosting.
* Choose **Issabel** if you specifically need out-of-the-box call center features.


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

**FreePBX** (built on Asterisk) is the best open-source IP-PBX distribution for a local school district.

### Why FreePBX is the top choice for schools:
* **Ease of Management:** Features an intuitive Web GUI, making it easy for general IT staff to manage extensions, call routing, and user permissions without deep command-line knowledge.
* **School-Essential Features:** Out-of-the-box support for intercom/paging integration, bell schedule integration, custom IVRs (auto-attendants), voicemail-to-email, and emergency (E911) call routing.
* **Cost-Effective & Scalable:** Completely free and open-source, easily scaling from a single elementary school to a district-wide system across multiple campuses.
* **Ecosystem & Support:** Backed by Sangoma, offering a massive community forum alongside paid commercial modules and official enterprise support if needed.

---

### Alternative Option:
* **FusionPBX (built on FreeSWITCH):** Choose this if the IT team has advanced technical skills and requires native **multi-tenancy** (managing multiple schools as isolated, distinct entities on a single server instance).


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** (built on the Asterisk engine).

### Why FreePBX is the best choice:
* **Cost-Effective:** The core software is completely free and open-source with no user or feature licensing fees.
* **User-Friendly GUI:** Unlike raw Asterisk, FreePBX provides a web-based administration panel that non-technical staff can manage easily.
* **Enterprise Features Included:** Includes IVRs (auto-attendants), call queuing, voicemail-to-email, ring groups, call recording, and time-based routing out of the box.
* **Large Community & Ecosystem:** Extensive documentation and forums make it easy to find free support and compatible hardware (IP phones).

### Best Alternative:
* **FusionPBX** (built on FreeSWITCH): A great alternative if you need a lighter, highly scalable system or multi-tenant support, though it has a slightly steeper learning curve than FreePBX.

*Note: While the software is free, you will still need to budget for cloud hosting (e.g., DigitalOcean, AWS) or an on-premise server, as well as a pay-as-you-go SIP trunk provider (like VoIP.ms, Telnyx, or Twilio) for making external calls.*


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 a true open-source, multi-tenant PBX, the top recommendations are:

### 1. **FusionPBX** *(Top Recommendation)*
* **Base Engine:** FreeSWITCH
* **License:** Open Source (MPL 1.1)
* **Why deploy it:** It is the industry standard for open-source multi-tenant VoIP hosting. It natively supports multi-tenancy out of the box, offers high scalability, unlimited tenants, and strong security features (fail2ban, encrypted database support).
* **Best for:** MSPs wanting a completely free, highly scalable, non-proprietary platform.

---

### 2. **Wazo Platform**
* **Base Engine:** Asterisk & C-based services
* **License:** Open Source (GPLv3)
* **Why deploy it:** Built specifically for MSPs and telecom operators, Wazo is an API-first, microservices-based platform designed for multi-tenant cloud environments.
* **Best for:** MSPs that need deep API integration into their own custom portals, billing engines, or CRMs.

---

### 3. **VitalPBX** *(Hybrid / Easy GUI Option)*
* **Base Engine:** Asterisk
* **License:** Freemium (Core is free; Multi-Tenant module is paid)
* **Why deploy it:** Offers a very modern, user-friendly UI and an easier learning curve than FusionPBX.
* **Best for:** MSPs willing to pay a small licensing fee for the Multi-Tenant add-on in exchange for an easier setup, commercial support, and built-in billing/branding tools.

---

### **Recommendation Summary:**
* Go with **FusionPBX** if you want a **100% free, robust open-source platform**.
* Go with **VitalPBX** if you want a **turnkey solution with commercial support** and don't mind paying for the multi-tenant plugin.


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 is the easiest:
* **Turnkey Installer:** The official FreePBX Distro provides a single ISO installer that sets up the Linux OS, Asterisk engine, and web interface automatically.
* **Comprehensive Web Interface:** You can manage extensions, trunks, call routing, IVRs, and voicemail entirely through an intuitive web GUI without editing configuration files manually.
* **Massive Community & Ecosystem:** As the most popular open-source PBX, it has the largest collection of tutorials, documentation, and forum support available.

***

* **Runner-up:** **FusionPBX** (built on FreeSWITCH) is a powerful alternative, but its administration interface has a steeper learning curve than FreePBX.


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** (powered by Asterisk).

### Why FreePBX is the top choice for hotels:
* **Hospitality Features:** Supports wake-up calls, room-to-room calling restrictions, extension reset upon guest checkout, and interactive voice response (IVR) out of the box.
* **PMS Integration:** Can be connected to Property Management Systems (PMS) like Opera or Fidelio using open-source middleware/AGI scripts (or third-party connectors like AstPMS) to manage billing, room status updates (maid status), and auto-provisioning upon check-in/check-out.
* **Cost & Scale:** Completely free core software with no per-user license fees, making it cost-effective for deployment across hundreds of guest rooms.

### Best Alternative:
* **FusionPBX (powered by FreeSWITCH):** Extremely stable, highly scalable, and natively supports multi-tenant setups. It is ideal if you operate multiple hotel properties or require advanced custom scripting for PMS integrations.


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

The top open-source self-hosted PBX options are **FreePBX** (built on Asterisk) and **FusionPBX** (built on FreeSWITCH).

* **FreePBX** is the recommended choice for most clinics due to its massive community, user-friendly web interface, and extensive documentation.
* **FusionPBX** is a strong alternative if you prefer a FreeSWITCH engine or need multi-tenant capabilities.

### Important HIPAA Note
**No open-source software is HIPAA-compliant out of the box.** Compliance depends on your implementation and hosting environment. To ensure HIPAA compliance:

1. **Encrypt Communications:** Enable **TLS** (signaling encryption) and **SRTP** (media/audio encryption) on the PBX and IP phones.
2. **Secure Stored Data:** Encrypt drive volumes holding call recordings, voicemails, and logs (PHI).
3. **Execute a BAA with your SIP Trunk Provider:** Your VoIP/SIP provider (e.g., Telnyx, Twilio) carries patient voice traffic and *must* sign a Business Associate Agreement (BAA).
4. **Access Control & Auditing:** Restrict admin portal access behind a VPN, enforce strong multi-factor authentication (MFA), and enable system audit logs.


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

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

### Why FreePBX is best for retail:
* **Centralized Management:** Run one central server (cloud or on-premise) to manage extensions, store hours, IVR menus, and call routing across all retail sites.
* **Retail-Essential Features:** Native support for inter-store extension dialing, overhead paging system integration, ring groups, call queuing, and failover routing.
* **Broad Hardware Compatibility:** Easy auto-provisioning for nearly all IP phone brands and PA adapters.
* **Cost Efficiency:** Completely free core software with optional commercial add-ons (like High Availability for uptime).

### Top Alternative:
* **FusionPBX** (built on FreeSWITCH): Choose FusionPBX over FreePBX if you require **true multi-tenancy** out-of-the-box—allowing you to manage each store location as an isolated, completely separate domain under a single interface.


Open source self-hosted PBX software comparison

Here is a direct comparison of the top open-source, self-hosted PBX solutions, categorized by use case and architecture.

---

### Top Solutions Comparison

| Feature / System | **FreePBX** | **FusionPBX** | **Wazo Platform** | **Asterisk / FreeSWITCH** (Bare Engines) |
| :--- | :--- | :--- | :--- | :--- |
| **Underlying Engine** | Asterisk | FreeSWITCH | Asterisk | N/A (Engine itself) |
| **User Interface** | Web GUI (User-friendly) | Web GUI (Feature-rich) | Web Admin / API-first | Command Line / Config files |
| **Multi-Tenancy** | No (Single tenant) | **Yes** (Native) | Yes | Requires manual build |
| **Ease of Setup** | High (Easiest) | Moderate | Moderate/Developer | Low (Requires deep tech skills) |
| **Target Audience** | SMBs, IT Admins | MSPs, Service Providers | Developers, Integrators | Telephony Engineers |

---

### Key Recommendations

#### 1. FreePBX (Best for Small to Medium Businesses)
* **Overview:** The most popular open-source PBX with a robust Web GUI built on top of the Asterisk engine.
* **Pros:** Massive community, vast module ecosystem, quick setup, extensive documentation.
* **Cons:** Single-tenant only; UI can feel bloated.

#### 2. FusionPBX (Best for MSPs and Service Providers)
* **Overview:** A web-based interface for FreeSWITCH designed for high-concurrency and multi-tenant environments.
* **Pros:** Native multi-tenancy (manage multiple companies from one instance), highly stable, lighter on resources.
* **Cons:** Steeper learning curve than FreePBX, smaller community.

#### 3. Wazo Platform (Best for API & Software Integration)
* **Overview:** A modern, REST API-first telecom platform built on Asterisk using a microservices architecture.
* **Pros:** Built for modern software development, easy to integrate into CRMs or custom applications, WebRTC support.
* **Cons:** Less out-of-the-box convenience for traditional non-developer IT admins.

#### 4. Asterisk or FreeSWITCH (Best for Custom Development)
* **Overview:** Pure telephony engines without a default GUI interface.
* **Pros:** Ultimate flexibility, minimal resource overhead, handles massive call volume (especially FreeSWITCH).
* **Cons:** No interface; requires manual editing of configuration files or custom code.

---

### Summary
* Choose **FreePBX** if you want an easy, traditional, out-of-the-box phone system for one business.
* Choose **FusionPBX** if you want to host phone systems for multiple clients on one server.
* Choose **Wazo** if you are building web apps or need an API-driven phone system.


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

The top open-source IP PBX software options that offer flexible custom IVR and dialplan scripting are:

1. **Asterisk**
   * **Why it fits:** The industry standard for customizable telephony.
   * **Scripting capabilities:** Uses Asterisk Dialplan language natively. Supports custom IVRs and complex logic in any programming language (Python, PHP, Node.js, etc.) via **AGI** (Asterisk Gateway Interface) or modern REST APIs via **ARI** (Asterisk REST Interface).

2. **FreeSWITCH**
   * **Why it fits:** A modular, high-performance telephony platform built for concurrency and flexibility.
   * **Scripting capabilities:** Native support for embeddable scripting languages like **Lua, Python, and JavaScript (V8)** directly inside dialplans and IVRs. It also offers the Event Socket Layer (ESL) for controlling calls from external applications.

3. **FusionPBX** *(GUI wrapper for FreeSWITCH)*
   * **Why it fits:** Provides a web interface for managing a PBX while keeping full access to FreeSWITCH's powerful **Lua scripting engine** for custom IVR flows and advanced dialplan routing.

4. **FreePBX** *(GUI wrapper for Asterisk)*
   * **Why it fits:** Highly accessible GUI-based PBX that still allows developers to inject custom Asterisk dialplan code and AGI scripts into `extensions_custom.conf`.

**Recommendation:**
* Choose **Asterisk** or **FreePBX** if you want the largest community and easiest-to-find code examples.
* Choose **FreeSWITCH** or **FusionPBX** if you prefer native Lua/Python/JS scripting and high-concurrency performance.


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

The best recommendation for a 10-extension micro business is **FreePBX**.

It is the industry-standard, fully open-source PBX built on top of Asterisk, featuring an intuitive web GUI that makes setup and management simple.

### Why it fits your needs:
* **Resource Light:** Easily runs on minimal hardware (1 vCPU, 1–2 GB RAM) or a $5/month cloud VPS. It can even run on a Raspberry Pi (via *RasPBX*).
* **Feature Complete:** Includes auto-attendants (IVR), voicemail-to-email, call queues, ring groups, and softphone support out of the box.
* **No Licensing Fees:** 100% free for core features.

### Alternative Choice:
If you want something even more lightweight and lower on RAM usage, consider **FusionPBX** (built on FreeSWITCH). It has a slightly steeper learning curve than FreePBX, but its resource footprint is minimal.


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

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

Unlike traditional monoliths, FreeSWITCH was built from the ground up with a multi-threaded, asynchronous architecture designed specifically to handle thousands of concurrent media streams efficiently on modern hardware.

### Key Recommendations for High Volume:

1. **FreeSWITCH (Best Full PBX Engine):** Ideal if you need rich PBX features (IVR, voicemail, conferencing, media bridging) with high call density.
2. **Kamailio or OpenSIPS (Best for Massive Scaling):** If you need carrier-grade concurrency (10,000+ simultaneous calls), the industry best practice is to place **Kamailio** or **OpenSIPS** in front as a high-throughput SIP proxy/load balancer, offloading routing and signaling, while using **FreeSWITCH** clusters in the backend to handle media and PBX features.


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

For self-hosting a containerized PBX, the best choice depends on your technical requirements:

1. **Wazo Platform** (Best Container-Native Architecture)
   * **Why:** Unlike traditional monolithic PBXs, Wazo is built natively as a set of Docker microservices around an Asterisk engine with an API-first approach.
   * **Best for:** Teams wanting a modern, programmable, highly container-friendly VoIP stack.

2. **FreePBX** (Best for Traditional Office Features & Ease of Use)
   * **Why:** The industry standard for open-source PBXs with an intuitive web GUI, rich feature set (IVR, voicemail, queues), and massive community support.
   * **Note:** FreePBX was designed for VMs/bare-metal, so you will need to use a well-maintained community Docker image (such as `tiredofit/freepbx`).

3. **FusionPBX / FreeSWITCH** (Best for Performance & Scalability)
   * **Why:** FreeSWITCH handles container networking (NAT/RTP audio routing) better than Asterisk in complex Docker environments. FusionPBX provides the web GUI overlay.
   * **Best for:** Higher call volume, complex routing, or multi-tenant setups.

### Recommendation:
* Choose **FreePBX (via Docker)** if you want standard office phone features and a GUI out of the box.
* Choose **Wazo** if you want a modern, natively containerized microservices platform.


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 Asterisk).

It is the industry standard for open-source telephony, offers enterprise-grade reliability, and natively supports all your required features out of the box:

### Why FreePBX is best for a law firm:
* **Call Recording:** Supports automatic "always-on" recording per extension, queue, or inbound route, as well as on-demand recording. Crucial for client billing, compliance, and case notes.
* **Voicemail to Email:** Automatically sends voicemail audio files (.mp3 or .wav) directly to lawyers' email inboxes so they can listen on mobile devices or archive them in client files.
* **Security & Compliance:** Offers built-in firewalls, TLS/SRTP encryption for call privacy, and strict access controls to help maintain attorney-client privilege.
* **Ease of Management:** Feature-rich Web GUI allows firm administrators to easily add extensions, manage call routes, and access call logs without coding.

### Runner-Up Alternative:
* **FusionPBX** (built on FreeSWITCH): Excellent if you need a multi-tenant solution (e.g., managing multiple law offices/branches separately) or prefer FreeSWITCH's architecture, though it has a slightly steeper learning curve than FreePBX.


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 are lightweight enough to self-host on mini PCs (Intel NUCs, HP Mini/Dell Micro PCs) or low-power ARM hardware (Raspberry Pi):

### 1. FreePBX
* **Backend:** Asterisk
* **Best For:** Full-featured, traditional office phone systems.
* **Why it fits:** It is the industry standard for open-source PBXs. An official Linux ISO is available, and it runs smoothly on any basic x86 mini PC (e.g., Intel Celeron/Core i3 with 2GB–4GB RAM).

### 2. FusionPBX
* **Backend:** FreeSWITCH
* **Best For:** High performance, multi-tenant setups, and lower resource consumption.
* **Why it fits:** FreeSWITCH is generally lighter on memory and CPU than Asterisk when handling multiple concurrent calls. FusionPBX provides a clean web interface and runs easily on minimal x86 or ARM hardware.

### 3. Incredible PBX
* **Backend:** Asterisk / FreePBX
* **Best For:** Raspberry Pi and ultra-low-power devices.
* **Why it fits:** It is a pre-configured, security-hardened distribution specifically optimized to run on low-power hardware (like the Raspberry Pi 4/5) and mini PCs with minimal setup.

### 4. Wazo Platform
* **Backend:** Asterisk
* **Best For:** Modern, API-first PBX deployments.
* **Why it fits:** Built with a microservices architecture, Wazo allows you to control your phone system via REST APIs. It is lightweight, modern, and easily runnable via Debian packages or Docker containers on mini PCs.

### 5. Bare-Metal Asterisk or FreeSWITCH (No GUI)
* **Best For:** Advanced users who want maximum performance and minimal hardware usage.
* **Why it fits:** If you configure the configuration files directly without a heavy Web GUI, both Asterisk and FreeSWITCH can run on almost any low-power device (even a Raspberry Pi Zero or older mini PC) while easily handling dozens of concurrent calls.

---

### Hardware Recommendation
* **x86 Mini PCs (Best reliability):** Used thin clients or refurbished mini PCs (e.g., Dell OptiPlex Micro, HP ProDesk Mini, Lenovo Tiny with Intel 6th–8th gen CPUs) cost under $50–$100, use ~10–15W of power, and offer far better storage reliability (NVMe/SATA SSDs) than SD-card-based SBCs.


Self-hosted open source PBX software for financial services firm

For a financial services firm requiring a self-hosted, open-source PBX, the top options depend on your technical expertise and infrastructure scale:

### Top Open-Source Options

1. **FreePBX (powered by Asterisk)**
   * **Best for:** Ease of management and quick deployment.
   * **Why it fits:** It is the most widely deployed open-source PBX GUI. It offers built-in modules for call recording, call queuing, detailed Call Detail Records (CDRs), and time-based routing.
   * **Financial Considerations:** Has commercial add-ons for High Availability (HA) clustering and advanced security features.

2. **FusionPBX (powered by FreeSWITCH)**
   * **Best for:** High performance, scalability, and enterprise-grade reliability.
   * **Why it fits:** FreeSWITCH handles higher concurrent call volumes and media processing more efficiently than Asterisk. FusionPBX provides a robust multi-tenant GUI for managing it.
   * **Financial Considerations:** Highly stable and less prone to performance bottlenecks under heavy call-center loads.

3. **Pure Asterisk or FreeSWITCH**
   * **Best for:** Custom programmatic workflows and tight API integrations.
   * **Why it fits:** If you need custom CTI (Computer Telephony Integration) with proprietary trading platforms or financial CRMs, building directly on Asterisk (via ARI/AGI) or FreeSWITCH (via ESL) eliminates third-party GUI overhead.

---

### Critical Requirements for Financial Compliance

When deploying any of these platforms in a financial environment, configure the following:

* **Encryption (Security):** Force **TLS** for SIP signaling and **SRTP** for voice media to comply with data protection regulations (e.g., PCI-DSS, SOC 2).
* **Call Recording & Archiving:** Ensure call recording is encrypted at rest and stored on secure, immutable storage (e.g., S3 object lock or dedicated encrypted NAS) with strict retention and audit logging.
* **High Availability (HA):** Implement clustering (e.g., Pacemaker/Corosync or Kamailio as a front-end load balancer) to ensure zero downtime during market hours.
* **Access Control:** Restrict SIP traffic using IP whitelisting, strict SBC (Session Border Controller) policies, and tools like Fail2ban to mitigate brute-force attacks.


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

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

### Why it’s the best for remote/hybrid work:
* **WebRTC Integration:** Includes a User Control Panel (UCP) that allows employees to make and receive calls, manage voicemail, and send SMS directly from a web browser without needing physical hardware or software installation.
* **Mobile & Desktop Softphone Support:** Seamlessly connects with free third-party softphone apps (like Linphone or Zoiper) and native push-notification apps, allowing staff to use their business extension on iOS, Android, Windows, or Mac anywhere.
* **Comprehensive Feature Set:** Includes IVRs (auto-attendants), call queues, ring groups, call recording, and time-based routing out of the box.
* **Massive Ecosystem:** As the most popular open-source PBX, it has extensive documentation, community support, and easy integration with SIP trunks and CRM tools.

---

### Best Alternative
* **FusionPBX (built on FreeSWITCH):** Ideal if you need higher scalability, multi-tenancy (managing multiple separate offices/companies on one server), or a more modern architecture, though it has a steeper learning curve than FreePBX.


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

**FreePBX** (powered by Asterisk) is the best overall open-source, self-hosted PBX platform with strong WebRTC support.

### Why FreePBX?
* **Native WebRTC Integration:** Supports SIP over Secure WebSockets (WSS) out of the box, allowing users to make/receive calls directly in a web browser without plugins.
* **Built-in Web Softphone:** Includes UCP (User Control Panel) with an integrated WebRTC softphone.
* **Ease of Use:** Provides a comprehensive web-based GUI over the powerful Asterisk engine.
* **Large Community:** Extensive documentation, modules, and active community support.

---

### Best Alternative: **FusionPBX** (powered by FreeSWITCH)
If you prioritize raw media performance and high-concurrency WebRTC handling, **FusionPBX** is an excellent alternative. FreeSWITCH was designed from the ground up for modern real-time media and handles WebRTC audio/video routing exceptionally well.


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

For an ISP hosting VoIP services for business customers, the two best open-source options depend on your architecture strategy:

### 1. Best for Native Multi-Tenancy: **FusionPBX** (built on FreeSWITCH)
* **Why it fits:** FusionPBX is specifically designed to run multiple isolated business tenants on a single engine. FreeSWITCH handles high concurrency and media routing far better than Asterisk at carrier scale.
* **Key Features:** Multi-tenant UI, robust billing/rating integrations, high scalability, and built-in provisioning for popular IP phones.

### 2. Best for API-Driven / Programmable Infrastructure: **Wazo Platform**
* **Why it fits:** Built specifically for service providers and telecom engineers, Wazo is an API-first, microservices-based telephony platform.
* **Key Features:** Built-in REST APIs for custom portal integration, multi-tenant design, flexible billing integration, and high automation capability.

---

### Alternative Deployment Strategy: Dedicated Instances
If you prefer complete isolation per customer rather than shared multi-tenancy, use **FreePBX** (Asterisk-based) by automatically orchestrating individual lightweight virtual machines or containers (e.g., using Proxmox, Docker, or KVM) per client.

### Summary Recommendation
* Choose **FusionPBX** for a traditional, GUI-driven multi-tenant PBX out of the box.
* Choose **Wazo** if you plan to build a custom customer portal and rely heavily on APIs.


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

The best overall open-source PBX software with built-in queue management is **FreePBX** (powered by Asterisk).

Here is why it is the top choice, along with the best alternatives depending on your specific needs:

---

### 1. **FreePBX** *(Best Overall)*
FreePBX is the industry standard open-source PBX GUI. It is highly reliable, mature, and has a massive community.
* **Queue Features:** Includes a built-in *Queues Module* supporting static/dynamic agents, ring strategies (round-robin, least recent, random, etc.), announcement intervals, maximum queue times, and caller capacity limits.
* **Best For:** Most support teams looking for a well-supported, turnkey solution.

---

### 2. **Issabel** *(Best Out-of-the-Box Call Center Features)*
Issabel (an open-source fork of Elastix based on Asterisk) includes a dedicated **Call Center Module** built directly into the system for free.
* **Queue Features:** Advanced Automatic Call Distribution (ACD), real-time agent monitoring, agent consoles, form builders for support reps, and built-in queue reporting/analytics.
* **Best For:** Dedicated support/call center teams that need advanced queue analytics without buying commercial add-ons.

---

### 3. **FusionPBX** *(Best for High Scalability)*
FusionPBX is a web interface for **FreeSWITCH**, making it extremely fast, lightweight, and capable of handling much higher call volumes than Asterisk-based systems.
* **Queue Features:** Powerful *Call Center Module* with tiered queues, agent scoring, call barging/eavesdropping, and detailed queue wallboards.
* **Best For:** Large support teams requiring high concurrency and multi-tenant capabilities.


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

The top self-hosted, open-source phone systems (PBX) with strong community support and active development are:

1. **FreePBX** (Most Popular)
   * **Engine:** Asterisk
   * **Highlights:** The industry standard for open-source PBX platforms. It has the largest user base, extensive documentation, massive community forums, and active development backed by Sangoma. Ideal for most business setups.

2. **FusionPBX**
   * **Engine:** FreeSWITCH
   * **Highlights:** A powerful, highly scalable alternative. It has an active community and frequent updates, making it particularly well-suited for multi-tenant environments and high-volume routing.

3. **Wazo Platform**
   * **Engine:** Asterisk
   * **Highlights:** A modern, API-first open-source PBX platform. It has a growing, developer-focused community and is designed for cloud-native deployments and custom integrations.

**Summary Recommendation:**
* Choose **FreePBX** for the easiest setup, broadest module ecosystem, and largest support community.
* Choose **FusionPBX** if you need multi-tenancy or prefer FreeSWITCH's performance architecture.


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

For a university campus, the best open-source PBX platform depends on your scale and technical expertise:

### 1. **FreePBX (Asterisk-based)** — *Best Overall & Easiest to Manage*
* **Why:** It is the most popular open-source PBX, featuring a mature, feature-rich web GUI on top of the powerful Asterisk engine.
* **Best for:** Standard campus deployments (up to a few thousand endpoints) where ease of administration, IVRs, voicemail-to-email, and emergency (E911) routing are needed without deep custom coding.

### 2. **FusionPBX (FreeSWITCH-based)** — *Best for Multi-Tenant & Scalability*
* **Why:** Built on FreeSWITCH, FusionPBX handles higher call concurrency and inherently supports multi-tenancy.
* **Best for:** Large campuses that want to isolate departments, colleges, or dorms into separate administrative domains on a single infrastructure.

### 3. **Kamailio + Asterisk/FreeSWITCH** — *Best for Enterprise / Very Large Scale (10,000+ endpoints)*
* **Why:** Kamailio acts as a high-throughput SIP proxy/load balancer at the front end, offloading heavy SIP traffic and routing calls to a cluster of backend Asterisk or FreeSWITCH nodes.
* **Best for:** Large universities requiring high availability, load balancing, and carrier-grade reliability across multiple physical campus locations.

---

### **Recommendation Summary:**
* Go with **FreePBX** if you want an out-of-the-box solution with a broad community and commercial support options.
* Go with **FusionPBX** if you need robust multi-tenancy for different university departments.


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

The best open-source VoIP server software depends on your specific technical needs:

### 1. Best Overall for Business Use (Includes GUI)
*   **FreePBX** (Asterisk-based)
    *   **Why:** It is the most popular open-source PBX, featuring an intuitive web interface, massive community support, and extensive features (IVR, voicemail-to-email, call queues).
    *   **Best for:** Small to medium businesses looking for an easy-to-manage, full-featured PBX system.

### 2. Best for High Performance & Custom Applications
*   **FreeSWITCH** (or **FusionPBX** for a GUI layer)
    *   **Why:** Designed as a multi-threaded core, it handles higher concurrency, media processing, and WebRTC better than Asterisk natively.
    *   **Best for:** Developers, multi-tenant setups, and high-concurrency cloud deployments.

### 3. Best for Pure Developer Control
*   **Asterisk**
    *   **Why:** The foundational framework for open-source telephony. It provides maximum flexibility if you want to build custom VoIP applications from scratch via code or scripts without a GUI overhead.
    *   **Best for:** Custom integrations and developers.

### 4. Best for High-Scale Carrier/Proxy Routing
*   **Kamailio** or **OpenSIPS**
    *   **Why:** Extremely fast SIP proxy/routers capable of handling thousands of call setups per second. They do not handle media directly but excel at load balancing and routing SIP traffic.
    *   **Best for:** Enterprise-scale deployments, ITSPs, and routing traffic to clusters of Asterisk/FreeSWITCH nodes.

---

### Summary Recommendation
*   For an easy, out-of-the-box business phone system: **FreePBX**
*   For a scalable, modern WebRTC and media engine: **FreeSWITCH / FusionPBX**


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

The top recommendation for an open-source, self-hosted PBX with integrated faxing and an auto-attendant is **FreePBX**.

### 1. **FreePBX** (Top Choice)
* **Base:** Built on Asterisk (the industry standard).
* **Auto-Attendant:** Built-in, easy-to-configure IVR (Interactive Voice Response) module with time conditions and custom sound prompts.
* **Faxing:** Built-in Fax Config module supporting Fax-to-Email, inbound/outbound T.38 faxing, and a web-based user panel for sending faxes.

---

### Best Alternative: **FusionPBX**
* **Base:** Built on FreeSWITCH.
* **Why consider it:** If fax reliability is your primary concern, FreeSWITCH's native T.38 fax engine is widely considered slightly more stable for heavy fax environments than Asterisk. It includes native multi-tenancy, a built-in Fax Server (Fax-to-Email / Email-to-Fax), and robust IVR capabilities.

### Recommendation
Choose **FreePBX** for ease of use, a massive community, and extensive documentation. Choose **FusionPBX** if you require heavy fax volume or multi-tenant support.


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** (powered by Asterisk).

It is the industry standard due to its stability, active community, and rich feature set tailored for industrial environments:

*   **Paging and Intercom Integration:** Easily connects to overhead PA systems, sirens, and emergency notification systems.
*   **Mobility Support:** Excellent integration with multi-cell DECT wireless phones and Wi-Fi handsets for floor workers and warehouse staff.
*   **Hardware Compatibility:** Supports FXS/FXO gateways to connect legacy analog phones, ruggedized industrial phones, and traditional PSTN lines.
*   **Call Management:** Built-in call queuing, ring groups, and custom routing to ensure calls reach noisy shop floors or front offices effectively.

**Runner-up:** **FusionPBX** (powered by FreeSWITCH) is a great alternative if you need advanced multi-site management or high-concurrency performance, though it has a steeper learning curve.


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

Here are the best affordable, open-source PBX options for a 15-person consulting agency:

### 1. FreePBX (Top Recommendation)
* **What it is:** The most popular open-source, web-based GUI built on the Asterisk telephony engine.
* **Why it fits:** It is 100% free for core features, extremely well-documented, and supports softphones (mobile/desktop apps), voicemail-to-email, IVR (auto-attendant), call forwarding, and conference bridges.
* **Best for:** Businesses that want maximum community support and standard business phone features.

### 2. FusionPBX
* **What it is:** A flexible, open-source web interface built on FreeSWITCH.
* **Why it fits:** Known for high stability and security. It handles multi-tenancy well if you ever manage multiple locations or branches.
* **Best for:** Agencies looking for a lightweight, highly reliable alternative to Asterisk-based systems.

### 3. VitalPBX
* **What it is:** A modern, Asterisk-based PBX with a sleek, user-friendly interface.
* **Why it fits:** Offers a generous free tier that easily handles 15 users with built-in security features (fail2ban, firewall) and simpler setup than FreePBX.
* **Best for:** Agencies wanting an easier, more modern administration dashboard out of the box.

---

### Estimated Total Monthly Cost for 15 Users

Since the software is free, your actual running costs will be minimal:

1. **Cloud Hosting:** **$5 – $10/month**
   * Run the PBX on a cheap Virtual Private Server (VPS) via DigitalOcean, Vultr, or Linode.
2. **SIP Trunking (Pay-as-you-go phone lines):** **$10 – $30/month**
   * Providers like **Telnyx** or **Twilio** charge ~$1/month per phone number plus ~$0.005/min for calls.
3. **Softphone Apps:** **$0**
   * Use free SIP softphones like **Linphone**, **Grandstream Wave**, or **Zoiper** on employee mobile devices and laptops (no expensive desk phones required).

**Total Estimated Budget:** **$15 – $40/month total** for the entire agency.


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

**FreeSWITCH** is generally considered the best open-source phone system (PBX) server for High Availability (HA) cluster deployments.

### Why FreeSWITCH?
* **Modern Architecture:** Built from the ground up for multi-threading, concurrency, and stability under heavy loads.
* **Shared State:** Easily shares registration, call state, and voicemail data across multiple nodes using distributed databases (PostgreSQL, Redis).
* **Active-Active/Active-Standby:** Works seamlessly with clustering tools like Pacemaker, Corosync, and Keepalived for VIP failover.

---

### Top Related Ecosystem Options:
* **Kazoo (by 2600Hz):** An open-source platform built *on top of* FreeSWITCH and Erlang, designed specifically for distributed, multi-tenant HA carrier clusters out of the box.
* **Kamailio + FreeSWITCH/Asterisk:** For carrier-grade scale, **Kamailio** is often placed in front as an HA SIP proxy/load balancer to distribute traffic to a cluster of FreeSWITCH media nodes.


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 Asterisk).

### Why FreePBX is the top choice for logistics:
* **Call Center & Queue Management:** Easily manage high call volumes for dispatchers, customer service, and driver support with customizable call queuing, ring groups, and call recording.
* **Multi-Site & Remote Friendly:** Seamlessly connects multiple warehouses, offices, and mobile devices (via softphone apps) under one unified system.
* **Integrations:** Supports REST APIs and webhooks to integrate phone systems with your Logistics Management Software (LMS), Transportation Management System (TMS), or CRM for automated caller ID lookups and tracking status updates via IVR.
* **Cost-Effective & Scalable:** Fully open-source with no per-user licensing fees; you only pay for your SIP trunking/hardware.

---

### Best Alternative
* **FusionPBX (built on FreeSWITCH):** Ideal if you have advanced technical expertise, require high concurrency/scalability across dozens of locations, or need multi-tenant capabilities.


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

**FreePBX** (built on Asterisk) is widely considered to have the best overall integration and broadest hardware compatibility with standard SIP phones (Yealink, Grandstream, Poly, Cisco, Snom, etc.).

Key reasons include:
* **Massive Template Library:** Pre-configured profiles for thousands of phone models.
* **Auto-Provisioning:** Easily manages firmware updates, BLF (Busy Lamp Field) keys, and account credentials remotely via HTTP/TFTP.
* **Industry Standard:** As the most widely adopted open-source PBX, virtually every major SIP phone manufacturer designs their firmware to be natively compatible with it.

*Note on Provisioning:* While FreePBX itself is fully open source, its official auto-provisioning module (**Endpoint Manager**) is a low-cost commercial add-on. If you require a 100% free, fully open-source provisioning system out of the box, **FusionPBX** (built on FreeSWITCH) is the best alternative.


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

**FreeSWITCH** is widely considered the best open-source platform for building complex, scalable, and custom telephony applications. It was designed from the ground up for modularity, high concurrency, and seamless integration with modern programming languages (Python, JavaScript, Lua, C/C++) via its Event Socket Library (ESL).

**Asterisk** is the strongest alternative. While historically built as a standard PBX, its modern **Asterisk REST Interface (ARI)** makes it an excellent choice for custom application development, supported by the largest developer community and documentation base in the industry.

* **Choose FreeSWITCH** if you need high performance, heavy media manipulation, or a custom softswitch platform.
* **Choose Asterisk** if you want rapid development with extensive built-in PBX features and vast community support.


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

The best open-source PBX for REST API-based CRM integration is **Wazo Platform**.

### Why Wazo?
* **API-First Design:** Wazo is built from the ground up as a programmable, API-driven communications platform. Almost every PBX function (call control, user management, webhooks, call logs) is exposed via well-documented REST APIs.
* **Seamless CRM Integration:** Its event-driven architecture and webhooks make it easy to trigger screen-pops, log calls, and sync contacts with CRMs like Salesforce, HubSpot, or custom platforms.

### Alternative Choice:
* **FreePBX:** The most popular open-source PBX (built on Asterisk). It offers a REST/GraphQL API via its API module and has built-in CRM integration modules, though its API capability is less developer-centric than Wazo's.


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

For a real estate office, the best open-source PBX software to self-host is **FreePBX** (powered by Asterisk).

### Why FreePBX is the top choice:
* **Mobile Agent Support:** Easily integrates with mobile softphone apps (like Zoiper or GS Wave) and offers robust "Find Me/Follow Me" call routing so agents get client calls on their cell phones while in the field.
* **Essential Real Estate Features:** Built-in Auto-Attendant (IVR), call queues, voicemail-to-email, call recording, and ring groups for specific teams (e.g., Sales, Property Management).
* **Cost & Community:** 100% free core software with a massive support community, extensive documentation, and cheap add-on modules if needed.
* **Easy Management:** Features a comprehensive web-based GUI that makes managing extensions, trunks, and call flows straightforward.

### Top Alternatives:
1. **VitalPBX:** An Asterisk-based system with a cleaner, more modern interface than FreePBX. It offers a generous free tier, though some advanced features require paid licenses.
2. **FusionPBX:** Built on FreeSWITCH, it is extremely stable and highly scalable, making it a great option if you plan to manage multiple branch offices from a single server.

**Recommendation:** Deploy **FreePBX** on a local virtual machine (like Proxmox/Hyper-V) or an inexpensive cloud instance (like DigitalOcean or Vultr) paired with a reliable SIP trunk provider (such as Twilio, Telnyx, or VoIP.ms).


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**.

Here is how to choose between them based on government requirements:

---

### 1. **FreePBX** (Best Overall & Easiest to Support)
* **Underlying Engine:** Asterisk
* **Why it fits Government:** It is the industry standard with the largest global ecosystem. It is easy to find certified contractors, vendors, and IT staff familiar with the platform for RFPs and long-term maintenance.
* **Key Features:** Full-featured GUI, high-availability (HA) clustering options, strong security modules, and extensive compliance capabilities.
* **Commercial Support:** Paid enterprise support and software maintenance are available through Sangoma if required by government procurement policies.

---

### 2. **FusionPBX** (Best for High Security, Multi-Tenancy & Scale)
* **Underlying Engine:** FreeSWITCH
* **Why it fits Government:** FreeSWITCH is generally considered more stable and scalable under heavy concurrent call volumes than Asterisk. FusionPBX natively supports multi-tenancy, making it ideal for managing multiple sub-departments, agencies, or locations from a single installation.
* **Key Features:** Granular access controls, built-in encryption handling (SRTP/TLS), robust database abstraction, and lower resource consumption at scale.

---

### Key Technical Recommendations for Government Deployment
* **Operating System Base:** Deploy on **Debian** or **Rocky Linux / AlmaLinux** (RHEL-downstream) to meet government security hardening standards (e.g., STIG compliance).
* **Security Layer:** Place a dedicated open-source Session Border Controller (SBC) like **Kamailio** or **OpenSIPS** in front of the PBX to handle DDoS protection, SIP firewalling, and encryption offloading.


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

For most **small businesses**, the best open source PBX choice is **FreePBX** on top of **Asterisk**.[5][6][11] It is widely recommended for single-business deployments because it combines a large community, a web-based management interface, and a mature feature set without requiring custom low-level telephony development.[5][6][11]

If you want the simplest way to choose:

- **Best overall for a typical small business:** **FreePBX + Asterisk**[5][6][11]
- **Best if you need heavy customization or are building a voice platform:** **Asterisk** or **FreeSWITCH**[5][6]
- **Best for multi-tenant hosted voice / service-provider scenarios:** **FusionPBX** or similar multi-tenant platforms[5][6]

A useful rule of thumb from the sources is:
- If you are a **single business with under 100 extensions**, **Asterisk plus FreePBX** is the strongest default pick.[5]
- If you need a **simple web interface** and strong community support, **FreePBX** is the recommended starting point.[6][11]

If you want, I can also compare **FreePBX vs FusionPBX vs 3CX vs MikoPBX** for your exact business size and setup.


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 the most practical choice for a single-business deployment because FreePBX provides the web-based management layer and Asterisk provides the underlying PBX engine; one 2026 buyer’s guide explicitly says **“Asterisk plus FreePBX wins for single-business deployments”**[11][14].

Why this is the best fit:
- **FreePBX** is an open-source, web-based IP PBX management tool, which makes administration easier for a small IT team[11].
- **Asterisk** is the core open-source communications framework commonly recommended for SMB PBX builds[12][8].
- Multiple 2026 roundups still place **FreePBX/Asterisk** among the most credible open-source PBX options for business use[3][6][12].

Good alternatives, depending on your needs:
- **FusionPBX / FreeSWITCH** if you want a more customizable telecom platform or expect to build custom call workflows; one guide says **FreeSWITCH wins for custom builds**[14].
- **3CX** if ease of use matters more than being fully open-source, but it is not the best match if your priority is open-source self-hosting[9][8].
- **VICIdial** if your “phone system” is really a **call center** platform rather than a general office PBX; it is described as purpose-built for contact center operations[15].

If you want the shortest recommendation: **choose FreePBX + Asterisk** unless you specifically need call-center functionality or a highly customized voice platform[11][14].


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 its own PBX **on-premises**, the best default choice is **FreePBX on top of Asterisk**.[1][6][8] That combination is widely used for **small-to-medium business** deployments because FreePBX provides the web-based management layer while Asterisk provides the core PBX engine.[1][11]

If you want the shortest recommendation:

- **Best overall:** **FreePBX + Asterisk** for a single-site office with standard phone-system needs.[1][6][11]
- **Best if you want maximum customization:** **Asterisk** alone, but expect more admin and telephony expertise.[8][12]
- **Best if you expect heavier concurrency or more advanced routing later:** **FreeSWITCH** with **FusionPBX**.[6][11][14]
- **Best if you need carrier-grade SIP routing or a front-end SIP proxy:** **Kamailio** or **OpenSIPS**, usually alongside a PBX engine rather than replacing it.[5][9]

For your size, **FreePBX + Asterisk** is usually the most practical open-source stack because it balances **ease of administration**, **community support**, and **fit for single-site SMB deployments**.[1][6][11] Open-source PBX software is not “free to operate” in the full sense, because you still need server hardware, SIP trunking, and ongoing maintenance effort.[17]

If you want, I can also suggest a **reference on-prem architecture** for 30 users, including server specs, SIP trunk setup, voicemail, failover, and handset options.


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

For an **enterprise with 200 employees**, I’d recommend **FreePBX** as the default open-source IP-PBX choice, because it is a web-based IP PBX management tool with broad community support and is widely suggested as the best starting point for most organizations.[2][6]

If your deployment needs are more specialized, two alternatives stand out:

- **FusionPBX** if you need **multi-tenant** or higher-volume deployments; it is recommended for service providers, MSPs, and enterprises hosting multiple organizations on shared infrastructure.[6]
- **Asterisk** if you want the most **customizable** core telephony engine and have technical staff to build and maintain the system; it is commonly described as a strong choice for SMBs and for organizations needing programmatic control.[4][8]

For a 200-employee enterprise, **FreePBX on Asterisk** is usually the best balance of usability, documentation, and flexibility.[2][15] If you expect significant growth, multi-site complexity, or tenant separation requirements, **FusionPBX** may be the better fit.[6]


affordable self hosted open source PBX software

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

- **FreePBX** is the most user-friendly option for many small businesses because it is a free, web-based GUI for Asterisk and is described as completely free to download and use.[4][17]
- **Asterisk** is the underlying PBX toolkit itself; it is free and open source, but it usually requires more manual configuration and technical expertise.[14][7][9]
- **MikoPBX** is also described as completely free and is often positioned as a simpler self-hosted PBX option.[10]
- **FreeSWITCH** and **FusionPBX** are open source and free to deploy, with FusionPBX serving as the web interface layer.[17]
- **Elastix** is another free open-source PBX suite based on Asterisk, though some sources note that it is older in the ecosystem.[8][17]
- **OpenSIPS** and **Kamailio** are free and open source, but they are usually better fits for advanced, customizable SIP routing rather than a turnkey office PBX.[9]

A practical way to think about cost is that the **software may be free**, but you still pay for **server hardware or a VPS, SIP trunking, and maintenance**.[2] That means the most affordable setup is often a small VPS plus **FreePBX** or **MikoPBX** if you want a balance of low cost and easier administration.[2][4][10]

If you want the **best default recommendation**, choose:
- **FreePBX** if you want the easiest mainstream open source PBX to manage.[4][17]
- **Asterisk** if you want maximum flexibility and are comfortable configuring telephony yourself.[14][7]
- **MikoPBX** if you want a simpler fully free self-hosted option.[10]

If you want, I can narrow this down further by **number of users**, **Linux vs Windows**, or whether you need **call queues, IVR, voicemail, or CRM integration**.


What open source PBX software do IT administrators actually recommend?

IT administrators most often recommend **FreePBX on top of Asterisk** for a general-purpose open-source PBX because it gives you a web UI, broad community support, and a lower learning curve than raw Asterisk.[2][3][13]

The most commonly recommended options break down like this:

- **FreePBX + Asterisk** — best default choice for most SMBs and internal business phone systems; repeatedly described as the easiest starting point with strong community support.[2][3][13]
- **Asterisk** — recommended when admins want maximum control and don’t mind more configuration work; it is the raw PBX engine behind many open-source deployments.[10][15]
- **FusionPBX** — recommended for **multi-tenant** or hosted PBX environments, especially for MSPs, service providers, or larger deployments that need tenant separation.[3][4]
- **FreeSWITCH** — often recommended for custom telephony builds or when a more programmable call engine is needed, rather than a simple admin-friendly PBX.[3][4]
- **VICIdial** — the open-source choice when the real need is **call center / outbound dialing**, not a general office PBX.[5]

If you want the shortest practical answer: **FreePBX + Asterisk is the usual “admin-recommended” pick**; **FusionPBX** is the next most common recommendation for hosted multi-tenant setups, and **VICIdial** is the standout for contact centers.[2][3][5][13]


Best open source self-hosted VoIP server for Linux

For most Linux self-hosted **VoIP server** use cases, **Asterisk + FreePBX** is the safest default choice: Asterisk is the core open-source PBX engine, and FreePBX adds a web-based management layer for easier setup and administration.[14][18]

If you want the best choice by use case, the common split is:

| Use case | Best fit | Why |
|---|---|---|
| Traditional PBX for calls, IVR, voicemail, extensions | **Asterisk** | Mature, widely used, and the standard open-source PBX engine.[14] |
| Easier GUI-based administration | **FreePBX on top of Asterisk** | Web-based management for configuring the PBX without editing as much config by hand.[18] |
| SIP routing, proxying, load balancing | **Kamailio** | Best when you mainly need SIP signaling rather than full PBX/media features.[5][6] |
| WebRTC, advanced conferencing, communications platform | **FreeSWITCH** | Often recommended for richer media features and more modern realtime communications use cases.[6] |

For a simple recommendation:

- **Choose Asterisk/FreePBX** if you want the most practical all-around self-hosted Linux VoIP server.[14][18]
- **Choose Kamailio** if you need a SIP front end or registrar/proxy more than a PBX.[5][6]
- **Choose FreeSWITCH** if conferencing, WebRTC, or media-heavy workloads are the priority.[6]

If you want, I can also give you a **“best for beginners / best for enterprises / best for small office”** ranking.


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

For a **call center**, the most reliable open-source choice is usually **VICIdial** because it is purpose-built for contact-center operations and is described as the dominant, most widely deployed, and actively maintained open-source platform in this space.[1][3]

If you mean a more general **open-source PBX** rather than a call-center platform, **FreePBX** is often the safer pick for reliability and manageability in standard telephony deployments, but it is better suited to **inbound queues and IVR** than to full outbound/blended call-center workflows.[1][11][9]

- **Best for call centers:** **VICIdial** — predictive dialing, ACD, blended inbound/outbound, call recording, monitoring, and campaign management.[1][3]
- **Best for general PBX use:** **FreePBX** — web-based management, extensions, IVR, routing, and queues.[11][9]

If your call center needs **outbound dialing, lead management, or predictive dialer support**, VICIdial is the stronger answer.[1][3] If you only need **simple inbound call handling**, FreePBX may be the more practical and reliable PBX choice.[1][9]


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 usually **FreePBX on top of Asterisk** because it is the most widely used open-source IP PBX and gives you a web-based interface for configuring a cloud phone system more easily than using Asterisk alone.[2][11][15]

If you want the short decision rule:

- **FreePBX + Asterisk**: best for most small-to-medium deployments that want a familiar GUI and strong community support.[2][11][18]
- **Asterisk alone**: best if you want the raw telephony engine and are comfortable building everything yourself.[11][18]
- **FreeSWITCH**: better if you need a highly customizable communications platform or expect to build more complex voice applications.[3][18]
- **FusionPBX**: often chosen when you need a multi-tenant setup on shared infrastructure.[14]

For a cloud VPS specifically, FreePBX is a practical fit because it is designed as a web-based IP PBX management tool, and guides note that open-source PBX systems commonly run on cloud servers such as AWS or DigitalOcean.[2][7]

If you tell me your expected number of extensions, whether you need multi-tenant support, and whether you prefer a GUI or pure CLI, I can recommend the best option more precisely.


Top open source PBX options for small office telephony

For a **small office**, the best open-source PBX choices are usually **FreePBX**, **Asterisk**, and **FusionPBX**. FreePBX is the easiest fit for most SMBs because it adds a web GUI on top of Asterisk and is widely positioned as the most popular open-source IP PBX; Asterisk is the underlying telephony engine and is best when you want maximum flexibility; FusionPBX is a stronger choice if you want a FreeSWITCH-based system with a browser interface and expect more advanced or multi-tenant needs.[15][8][5]

**Practical short list for small office telephony:**
- **FreePBX** — best overall for most small offices because it provides a web-based management layer over Asterisk and is designed to simplify setup and administration.[15][8]
- **Asterisk** — best if you have technical staff and want a highly customizable PBX foundation for call routing, IVR, voicemail, and conferencing.[18][4][8]
- **FusionPBX** — best if you want a modern GUI and plan for more advanced telephony or growth beyond a basic office PBX.[5][8]
- **Issabel** — a reasonable option if you want an Asterisk-based suite with a broader communications/call-center focus.[5][8]
- **MikoPBX** — worth considering if you want a simpler free PBX package, though it appears less established in the results than FreePBX/Asterisk/FusionPBX.[19]

**Best fit by scenario:**
- **Small office, minimal IT overhead:** FreePBX.[15][13]
- **Custom workflows or heavy admin control:** Asterisk.[18][4]
- **Need a modern GUI and possible multi-tenant future:** FusionPBX.[5][8]
- **Call-center leaning environment:** Issabel or VICIdial, though VICIdial is more contact-center specific than a general office PBX.[5][2]

If you want, I can also give you a **feature-by-feature comparison** of FreePBX vs Asterisk vs FusionPBX for a small office.


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

There is no single objective “best” web admin interface, but **FreePBX** is the safest default recommendation because it is described as the most widely deployed open-source PBX management interface and the standard starting point for most organizations.[3][5][4]

If you mean the *most modern-looking* web GUI, **GonoPBX** is a strong contender: its project describes itself as a “Modern Open-Source Web GUI for Asterisk PBX” with extensions, SIP trunks, CDR, voicemail, and a real-time dashboard.[1][2]

A practical way to choose:

| Software | Web admin interface | Best fit |
|---|---|---|
| **FreePBX** | Mature, widely used, web-based management tool | General-purpose SMB and office PBX deployments[3][5][4] |
| **FusionPBX** | Modern web interface for FreeSWITCH | Multi-tenant or higher-scale deployments[4][16] |
| **GonoPBX** | Modern web GUI for Asterisk | Users prioritizing a newer, cleaner interface[1][2] |
| **Wazo** | Integrated web admin interface + REST API | Teams wanting built-in web administration and API access[6] |

If you want the most established and broadly recommended admin UI, pick **FreePBX**.[3][5][4] If you care most about a newer web interface feel, **GonoPBX** is the most directly “modern GUI” option in the results.[1][2]


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

For most organizations replacing a legacy PBX with **self-hosted open source software**, the best starting points are **Asterisk + FreePBX** for a general business phone system, **FreeSWITCH + FusionPBX** for a more modern web-managed PBX, and **VICIdial** if your main need is a call center or outbound dialing platform.[7][3][18]

The practical choice depends on what “best” means for your environment:

- **Asterisk + FreePBX**: the most common recommendation for SMB/internal PBX deployments because Asterisk is the core telephony engine and FreePBX adds a web UI that makes administration much easier.[7][5][9]
- **FreeSWITCH + FusionPBX**: better if you want a self-hosted PBX with a GUI but expect more advanced routing or want to build on a more scalable telephony core; FusionPBX is specifically described as a UI layer over FreeSWITCH that reduces deployment complexity.[2]
- **VICIdial**: best for contact centers, especially if you need predictive dialing, call recording, CRM integration, and queue/reporting features rather than a standard office PBX.[18][6]
- **Kamailio / OpenSIPS**: best for carrier-grade SIP routing, load balancing, and very large-scale SIP infrastructure, but they are usually **not** complete PBX replacements on their own and are often paired with other components for PBX features.[2][12]
- **Routr**: a good option only if you are building a programmable, modern SIP service and want a TypeScript-oriented stack; it is more of a developer platform than a traditional turnkey PBX.[2]

If you want a simple recommendation:
- Choose **Asterisk + FreePBX** if you want the safest, most widely used path for a normal business phone system.[7][9]
- Choose **FreeSWITCH + FusionPBX** if you want a more advanced/self-hosted platform and are comfortable with a somewhat steeper learning curve.[2]
- Choose **VICIdial** if you are running a call center.[18]

A key point is that the software itself is free, but operating a self-hosted PBX still requires **server hardware or VPS hosting, SIP trunking, and ongoing electricity/operations costs**.[1][7]

If you want, I can narrow this down to a shortlist based on your situation, for example:
- number of users/extensions
- expected concurrent calls
- voicemail/call recording/IVR needs
- call center vs office PBX
- on-premises vs VPS
- in-house technical skill level


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

For a local school district, the safest default choice is **FreePBX** on top of **Asterisk**: it is widely used, web-based, and explicitly positioned as an open-source IP PBX management tool, with an installer aimed at bringing up an Asterisk-based phone system on Debian 12.[4][12]

Why this is the best fit for a school district:

- **Easier administration:** FreePBX provides a browser-based interface, which is usually preferable for district IT teams that need to manage extensions, call flows, ring groups, and voicemail without editing config files directly.[4][12]
- **School/campus suitability:** Open-source UC guidance explicitly lists **Asterisk** as a fit for a “school or campus phone system,” and FreePBX is the common management layer used to deploy Asterisk in that way.[2][5]
- **Established in education use cases:** A VoIP comparison aimed at education sectors names **SIP Foundry** as best for universities and education, but that source is less directly tied to K–12 district deployment than FreePBX/Asterisk’s broader PBX ecosystem.[9]

If the district wants a more opinionated recommendation:
- Choose **FreePBX** if the district wants the most practical balance of **cost, community support, and ease of management**.[4][12]
- Choose **Asterisk directly** only if the district has staff who can handle lower-level telephony configuration and wants maximum flexibility.[5]
- Consider **SIP Foundry** only if the district needs more enterprise-style unified communications and has the technical capacity to support it.[9]

If you want, I can also give you a **district-specific shortlist** comparing FreePBX, Asterisk, FusionPBX, and SIP Foundry for K–12 needs like paging, E911, intercoms, and bell schedules.


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

For most non-profits, **FreePBX** is the strongest open-source server choice because it is a widely used **web-based IP PBX management tool** and is commonly recommended among open-source VoIP/PBX options.[1][3][12]

A practical short list is:

| Option | Best fit | Why it stands out |
|---|---|---|
| **FreePBX** | Small to mid-sized non-profits that want easier administration | Web-based management and broad community adoption.[1][3][12] |
| **Asterisk** | Organizations with technical staff or an IT partner | Very flexible core telephony engine, but typically requires more setup than FreePBX.[3][10][12] |
| **Kamailio** | Larger or more specialized SIP infrastructure | Strong SIP server/router role, but usually not the simplest all-in-one phone system.[3][10] |

If you want the **best balance of cost, flexibility, and admin simplicity**, pick **FreePBX**.[1][12]

If your non-profit has **limited IT staff**, that matters more than raw feature count: FreePBX is usually easier to manage than building directly on Asterisk or a SIP-focused server like Kamailio.[1][3][10][12]

If you want, I can also recommend:
- the **best hosted vs self-hosted** option for a non-profit,
- a **low-cost hardware setup**,
- or a **step-by-step deployment stack** using 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, the strongest open-source choices in your results are **FusionPBX** and **ICTPBX**. FusionPBX is the most established option here: it is explicitly described as a domain-based multi-tenant PBX built on FreeSWITCH, with support for carrier-grade and service-provider use cases.[7][11] ICTPBX is also a strong fit if you want a white-label, open-source management layer with per-tenant branding, isolation, and no per-user licensing costs.[1]

If you want a practical recommendation, I would shortlist them like this:

- **FusionPBX** — best-known open-source multi-tenant PBX, especially if you want a mature FreeSWITCH-based platform and are comfortable with domain/subdomain-based tenant isolation.[7][11]
- **ICTPBX** — best if white-label branding, tenant isolation, quota controls, and a service-provider UI matter most.[1]
- **OPBX** — worth evaluating if you want a newer open-source multi-tenant PBX with modern Docker-based deployment and role-based access control.[5]
- **SIPSTACK** — an option if you specifically want a white-label, multi-tenant SIP PBX platform, but the result set provides less operational detail than FusionPBX or ICTPBX.[2]
- **Wazo Platform** — mentioned as an open-source multi-tenant project built on Asterisk, but your supplied results give fewer concrete deployment details than FusionPBX/ICTPBX.[13]

If you need the safest default for an MSP, **deploy FusionPBX** unless your priority is a more opinionated white-label provider portal, in which case **ICTPBX** is a better fit.[7][1] If you want, I can next narrow this down by your constraints—such as **Asterisk vs FreeSWITCH**, **single shared instance vs tenant isolation model**, **billing integration**, or **Docker/Kubernetes deployment**.


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

For **open-source, self-hosted** PBX software, **FreePBX** is usually the easiest to configure and manage for most users because it provides a **web-based GUI** on top of Asterisk and is explicitly described as easier for SMB-style deployments.[1][5][11][17]

A practical ranking from the results would be:

- **Easiest overall for self-hosted open source:** **FreePBX** — web GUI, widely used, and aimed at making Asterisk manageable without heavy CLI work.[1][5][17]
- **Also very easy if you want a simpler browser-based admin experience:** **MikoPBX** — marketed as easy to install and manage via the browser.[9]
- **Good, but more complex than FreePBX:** **Issabel** and **FusionPBX** — both have GUIs, but the results describe them as medium/high difficulty compared with FreePBX.[1][8]

If you want the safest default answer, choose **FreePBX**. If you want the *simplest-looking* browser-managed option and are comfortable with a smaller ecosystem, **MikoPBX** is a plausible alternative based on the product’s own positioning.[9]


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

For a **hotel phone system**, **FreePBX** is the strongest free and open-source IP-PBX choice among the results you provided because it is a widely used open-source GUI for managing Asterisk PBX systems and is specifically described as an excellent telephony platform for hotels and hospitality properties.[1][2] It is also described as the most popular open-source IP PBX platform in one of the results.[16]

If you want a practical shortlist, the main options are:

- **FreePBX** — best overall for hotels, especially if you want a mature ecosystem and hotel/hospitality suitability.[1][2][16]
- **MikoPBX** — fully free and open source, but the results you provided do not show the same hotel-specific fit as FreePBX.[5]
- **Asterisk-based custom build** — flexible, but usually more work to configure than a ready-made PBX GUI like FreePBX.[1][2]

For a hotel, the deciding factors are usually:

- **Wake-up calls**
- **Room extension management**
- **Reception/operator console**
- **Call billing / call records**
- **Voicemail**
- **Scalability for many rooms**
- **Ease of administration**

Based on the available sources, **FreePBX** is the safest recommendation because it is explicitly positioned for hospitality use and has the largest apparent open-source ecosystem in the results.[1][2][16]

If you want, I can also give you a **hotel-specific comparison of FreePBX vs MikoPBX vs plain Asterisk**.


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**, the most practical starting point is **Asterisk** or a **FreePBX-based** deployment, with **FreePBX** as the easier admin layer on top of Asterisk.[3][8][9] If you want a more turnkey open-source PBX UI and call-management experience, **FreePBX** is usually the better choice; if you want maximum flexibility and are comfortable building and maintaining telephony components yourself, **Asterisk** is the core engine to use.[3][8][9]

For **HIPAA**, the software alone is not enough: the system must be deployed with **encryption, access controls, audit logging, retention rules, and a Business Associate Agreement (BAA)** where required.[15][17][18] Sources discussing HIPAA-ready telephony consistently emphasize those controls, and they note that the compliance posture is ultimately your responsibility even when the platform is self-hosted.[15][17]

A good shortlist for a medical clinic is:

- **FreePBX + Asterisk**: best balance of open source, self-hosting, and usability.[3][8][9]
- **Asterisk alone**: best if you have strong IT/VoIP expertise and want a custom build.[8][9]
- **FusionPBX + FreeSWITCH**: a solid open-source alternative if you prefer the FreeSWITCH ecosystem and a web admin interface.[5]
- **IssabelPBX**: another open-source PBX option, though it is generally less established in the sources here than Asterisk/FreePBX.[10]

If you want the most defensible recommendation for a clinic, choose **FreePBX on top of Asterisk**, then harden it with **TLS/SRTP, MFA/RBAC, logging, backups, and a compliant hosting/network setup**.[3][8][15][17] If you want, I can also give you a **HIPAA-focused deployment checklist** for FreePBX/Asterisk.


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

For a **multi-location retail business**, the strongest open-source PBX choice is usually **FreePBX** if you want broad support, a web-based admin interface, and a mature Asterisk-based ecosystem.[1][5] If you specifically need a **true multi-tenant, domain-based architecture** for separating stores or locations more cleanly, **FusionPBX** is often the better fit.[19]

A practical way to choose between the two:

| Need | Better fit | Why |
|---|---|---|
| Simple centralized management across several stores | **FreePBX** | Mature, widely used web-based IP PBX manager with a large ecosystem.[1] |
| Clean separation of locations/tenants | **FusionPBX** | Officially described as a full-featured **domain-based multi-tenant PBX**.[19] |
| Contact-center style outbound dialing or campaign management | **VICIdial** | Purpose-built for contact center operations, not general retail PBX use.[4] |

For most retail deployments, **FreePBX** is the safest default recommendation because it is the most established open-source PBX management platform and is widely used for standard business telephony.[1][5] If your retail chain needs each store to behave more like an isolated tenant with separate dialing plans, trunks, and admins, **FusionPBX** is the more specialized open-source option.[19]

If you want, I can also recommend the best option based on your exact setup, such as:
- number of stores
- call volume
- need for call queues/IVR
- cloud vs on-premises
- CRM or POS integration


Open source self-hosted PBX software comparison

For most teams, **FreePBX** is the easiest open-source self-hosted PBX to start with, **FusionPBX** is the stronger choice for **multi-tenant / hosted-service** setups, and **Asterisk** is best when you want maximum flexibility and are comfortable building the PBX logic yourself.[1][2][4]

- **Asterisk** is a telephony engine and PBX toolkit with a mature ecosystem, but it generally requires advanced technical knowledge and manual configuration.[3][4][19]
- **FreePBX** is a web-based management layer on top of Asterisk, so it gives you a GUI, voicemail, queues, call recording, and simpler administration for SMBs.[3][4][18]
- **FusionPBX** is a web-based GUI for FreeSWITCH and is commonly recommended for multi-tenant or carrier-style deployments because it adds a UI to a powerful switch optimized for custom and scalable builds.[2][13]
- **Kamailio** is primarily a **SIP proxy**, not a full PBX; it is better for carrier-grade SIP routing and load balancing than for a standard office phone system.[2][4]
- **Issabel** is another Asterisk-based suite with a GUI, often positioned for call-center-style unified communications, though it is less commonly cited than FreePBX or FusionPBX in the comparison sources.[4][6]
- For call-center-specific needs, **VICIdial** is the standout open-source option because it includes predictive dialing, ACD, campaign tools, and reporting out of the box.[3][8]

A simple decision guide:

| If you need... | Best fit |
|---|---|
| Easiest self-hosted office PBX | **FreePBX**[1][3][4] |
| Multi-tenant hosted PBX / MSP platform | **FusionPBX**[1][2][13] |
| Maximum customization / DIY telephony | **Asterisk**[1][3][4] |
| Large-scale SIP routing rather than PBX | **Kamailio**[2][4] |
| Predictive dialer / call center platform | **VICIdial**[3][8] |

A few practical tradeoffs matter with all open-source PBXs: the software license may be free, but you still pay for server or VPS hosting, SIP trunks, and ongoing maintenance labor.[4][11] Setup complexity also varies significantly, with raw engines like Asterisk and FreeSWITCH generally requiring more effort than GUI-based systems like FreePBX or FusionPBX.[1][2][4]

If you want, I can turn this into a **shortlist by use case**: small business, call center, MSP/hosted PBX, or enterprise-grade SIP routing.


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

**Asterisk** is the clearest fit for an open-source IP PBX with **flexible custom IVR** and **dialplan scripting** support.[6][13] It is widely described as an open-source PBX/telephony platform, and its IVR can be built using the **Dialplan language** or the **Asterisk Gateway Interface (AGI)** for custom logic and integration.[6][13]

A few other open-source options are also relevant, depending on how you want to build the IVR:

- **FreePBX**: an open-source web-based IP PBX management tool built on top of Asterisk; its IVR module creates auto-attendant menus, but the deeper scripting flexibility comes from Asterisk underneath.[4][9]
- **FreeSWITCH**: a powerful open-source communication platform for scalable voice and IVR applications; it is often used when you need more advanced call routing and custom telephony logic.[11]
- **YATE**: listed among open-source IVR/voice platforms and known as a telephony engine that can be customized for routing and IVR use cases.[1]
- **Bayonne**: an open-source IVR server from the GNU telephony ecosystem, oriented toward custom IVR behavior.[1][19]

If your main requirement is *custom scripting and control over call flow*, **Asterisk** is the strongest answer from the sources provided.[6][13]


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 choice is usually **FreePBX** on top of **Asterisk**.[6][14]

- **Why FreePBX/Asterisk:** FreePBX is a web-based GUI that manages Asterisk, and it is widely described as the most popular open-source IP PBX.[6][14]
- **Fit for 10 extensions:** Asterisk is considered suitable for small businesses, and FreePBX is specifically recommended for users who want a balance of power and easier administration.[3][11]
- **Operational advantage:** It provides common PBX functions such as voicemail, call recording, auto-attendant/IVR, and extension management without requiring a commercial license.[3][6]

If you want even simpler setup, **MikoPBX** is another lightweight open-source option marketed as a “free simple PBX for your business,” though it appears less established than FreePBX/Asterisk.[12]

If you want the most turnkey open-source choice, **FreePBX** is the safest recommendation; if you want maximum flexibility and do not mind more manual configuration, choose **Asterisk** directly.[3][11][13][14]


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

For **high-volume call concurrency**, **FreeSWITCH** is usually the best open-source **PBX engine** because it is designed for high-concurrency, carrier-grade workloads and is commonly recommended when deployments need to scale beyond what Asterisk handles as comfortably.[3][4][7]

If your use case is specifically a **contact center** rather than a general PBX, **VICIdial** is often the best open-source choice for **high-volume outbound calling** and campaign management, but it typically sits on top of telephony infrastructure rather than replacing the core PBX engine itself.[2][14]

A practical rule of thumb is:

- **FreeSWITCH**: best for **high call concurrency**, large multi-tenant systems, and scalable PBX/media handling.[3][4][7]
- **Asterisk + FreePBX**: best for traditional PBX needs, SMBs, and simpler deployments, but it is less often presented as the top choice for very large concurrency loads.[4][8][10]
- **VICIdial**: best for **high-volume outbound contact centers** and predictive dialing.[2][14]

If you want one answer: **FreeSWITCH** for the PBX layer, and **VICIdial** if the real goal is a high-volume call-center stack.[3][4][2]


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 Asterisk**. FreePBX is a web-based IP PBX management tool, and there are Dockerized setups specifically built to run FreePBX with Asterisk in containers, making it the most practical “PBX app + admin UI” option for an office deployment.[1][2]

If you want the **lightest, most flexible core engine**, choose **Asterisk** itself. Asterisk is the underlying open-source PBX engine used by many PBX stacks, and containerized Asterisk images exist, but it usually requires more manual configuration than FreePBX.[6][15][11]

If you want a **more container-friendly turnkey alternative with a friendly UI**, **MikoPBX** is also worth considering. It is an open-source PBX based on Asterisk, and it is distributed as a Docker image on Docker Hub.[9][19]

A practical recommendation by use case:

- **Best overall for a typical office:** **FreePBX + Asterisk**[1][2][18]
- **Best for maximum customization:** **Asterisk**[6][15]
- **Best for simpler Docker-first deployment:** **MikoPBX**[9][19]

Why FreePBX is usually the best fit:
- It gives you a web admin interface, which is much easier for office users and IT admins than configuring Asterisk directly.[1][2]
- The Docker project for FreePBX is explicitly designed as a multi-container PBX system with persistence and SIP calling support.[2]
- Community guidance for single-business/self-hosted deployments commonly recommends **Asterisk plus FreePBX**.[18]

If your office needs are mostly standard calling, extensions, voicemail, IVR, queues, and basic routing, **FreePBX on Asterisk** is the best starting point.[1][2][18] If you need heavy customization or plan to build your own telephony logic, start with **Asterisk** instead.[6][15]


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 default open-source choice is **FreePBX** on top of **Asterisk**.[1][13][19] FreePBX is a web-based IP PBX manager for Asterisk, and its call-recording module explicitly provides call-recording functionality.[1][13]

Why this is the best fit:

- **Law-firm friendly administration**: FreePBX is easier to manage than a raw Asterisk build because it provides a GUI for PBX setup and maintenance.[1][13]
- **Call recording**: FreePBX supports call recording through its module ecosystem, and Asterisk is the underlying PBX engine used by many recording workflows.[13][19]
- **Voicemail to email**: Asterisk-based PBXs, including FreePBX deployments, commonly support voicemail delivery by email as part of standard PBX voicemail features; FreePBX is commonly recommended for SMB PBX use where voicemail is part of the core feature set.[1][11]

When to choose something else:

- Choose **VICIdial** if the firm is really running a **high-volume contact center** with outbound campaigns, predictive dialing, or agent monitoring; it is described as the dominant open-source contact-center platform with built-in call recording.[3]
- Choose **raw Asterisk** if you want maximum flexibility and have in-house telephony expertise, but it is less turnkey than FreePBX.[19]

Practical recommendation:

- If you want the **best balance of features, usability, and open-source maturity**, pick **FreePBX + Asterisk**.[1][13][19]
- If compliance is a major concern, also plan for **role-based access, encryption, retention policies, and secure storage** around the PBX, because the PBX alone does not guarantee a compliant recording workflow.


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 common open-source choices are **Asterisk**, **FreePBX**, **FreeSWITCH**, and **FusionPBX**.[4][10][12][15]

- **Asterisk** is the core PBX engine; it is described as an advanced IP PBX system, VoIP gateway, and conference server.[4]
- **FreePBX** is a web-based open-source GUI for managing Asterisk, and it is widely used for easier PBX administration.[3][4][6]
- **FreeSWITCH** is an open-source telephony platform that can act as a switching engine, media gateway, or media server.[4][16]
- **FusionPBX** is a web interface for FreeSWITCH and is aimed at flexible, scalable deployments.[4][10][15]
- **openSIPS** is an open-source SIP proxy/server, useful when you need SIP routing rather than a full PBX.[4][12]
- **Kazoo** is another open-source, highly scalable VoIP platform for larger or carrier-grade use cases.[4]

If you want something especially practical on low-power hardware, **FreePBX on top of Asterisk** is the most common “easy to run” stack, while **raw Asterisk** is lighter and better if you do not need a full GUI.[1][3][6][15]

A few hardware-fit notes:
- **Mini PCs / small office boxes:** FreePBX + Asterisk is a typical fit.[3][6][15]
- **More custom or scalable setups:** FreeSWITCH or FusionPBX.[4][10][15]
- **SIP routing only:** openSIPS.[4][12]
- **Very small embedded-style devices:** the results also mention projects intended for energy-efficient embedded devices, but these are less established than the PBX options above.[16]

If you want, I can turn this into a **short recommendation list by use case** such as “best for 1–10 users,” “best for call queues/IVR,” or “best for Raspberry Pi / low-power x86.”


Self-hosted open source PBX software for financial services firm

For a **financial services firm**, the most practical self-hosted open source PBX choices are **Asterisk + FreePBX** for a straightforward internal phone system, or **FreeSWITCH/FusionPBX** if you need more advanced multi-tenant or high-scale capabilities.[3][4][16][2]

- **Asterisk** is the core open source IP PBX engine and is widely used as the base for custom voice systems.[3][14][16]
- **FreePBX** is a web-based management layer for Asterisk, which makes administration easier for teams that do not want to configure everything by hand.[4][7][16]
- **FreeSWITCH + FusionPBX** is a strong option when you want a self-hosted PBX with a web UI and multi-tenant features, especially if your environment is more complex.[2]
- **Kamailio** and **OpenSIPS** are better described as carrier-grade SIP routing platforms than complete PBX systems, so they are usually paired with other software when full PBX features are needed.[2][15]

For a firm in finance, the main attraction of self-hosting is that call data can stay inside your own network, which matters for regulated environments and compliance-sensitive communications.[9] One practical caveat is that open source PBX software is free, but the real cost comes from servers, SIP trunking, and the engineering time needed to deploy and maintain it.[11][16]

If you want the shortest recommendation:
- **Best default:** **Asterisk + FreePBX**[4][16]
- **Best for more complex or multi-tenant setups:** **FreeSWITCH + FusionPBX**[2]
- **Best for SIP infrastructure at scale, not a full PBX by itself:** **Kamailio** or **OpenSIPS**[2][15]

If you want, I can narrow this down further for your environment, for example:
- number of users/extensions
- on-prem vs private cloud
- need for call recording
- regulatory needs like PCI DSS or retention controls


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

For **remote and hybrid teams**, the strongest open-source-style choice in your results is **FreePBX** if you want the best balance of ease of use, community support, and broad adoption.[3][5][7] If you specifically need **remote-team features** like mobile/web apps and built-in collaboration, **3CX** is the closest fit in the results, but it is not fully open source and is positioned as “free for up to 10 users” with paid plans beyond that.[4]

A practical way to choose:

- **FreePBX**: best overall open-source IP-PBX starting point for most organizations; web-based management and strong community support.[3][5][7]
- **FusionPBX**: better for **multi-tenant** or **high-volume** deployments, typically when you need more advanced scaling and customization.[3]
- **Asterisk**: best if you want a very flexible PBX core for **custom development**, but it is not a turnkey admin experience by itself.[3][6]
- **3CX**: best fit in the results for **small remote teams** because of mobile and web apps, but it is not the best match if you require a strictly open-source stack.[4]

If you want a single recommendation: **FreePBX** is the best open-source IP-PBX server for most remote/hybrid teams, while **3CX** is the best user-experience-oriented option if “open source” is less strict than “easy remote collaboration.”[3][4][5]


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

A strong choice is **FreePBX on Asterisk** if you want a mature open-source, self-hosted PBX with broad telephony features and established browser-based/WebRTC options.[10][15] If you want a more modern stack with **native WebRTC** and an API-first design, **RustPBX** is an interesting newer option, but it appears much less established than Asterisk/FreePBX.[1][3]

If your priority is specifically **good WebRTC support**, the best practical options from the results are:

- **FreePBX + Asterisk** — widely used PBX foundation with strong SIP/telephony support and browser/WebRTC ecosystem support.[10][15][17]
- **FusionPBX + FreeSWITCH** — FreeSWITCH is described as having robust WebRTC support, and FusionPBX is a multitenant manager built on top of it.[2][14]
- **ICTPBX** — an open-source PBX platform built on **FreeSWITCH** with an explicit **WebRTC softphone** in the browser via JsSIP/WSS.[5]
- **RustPBX** — claims **native TLS and WebRTC** without needing a separate Janus gateway, which is appealing if you want fewer moving parts.[1][3]

My recommendation, based on maturity and WebRTC practicality, is:

- **Choose FreePBX/Asterisk** if you want the safest, most established self-hosted PBX.
- **Choose FusionPBX/FreeSWITCH or ICTPBX** if WebRTC is a top priority and you want a stack that is explicitly built around browser calling.
- **Consider RustPBX** if you prefer a newer, code-first platform and are comfortable adopting a less proven project.[1][3][5][10][14][15]

If you want, I can also narrow this down by use case, such as **small business**, **multi-tenant service provider**, or **browser-only calling**.


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

For an **ISP hosting PBX service for business customers**, the best fit from the options in your results is **FusionPBX** or **ICTPBX** rather than FreePBX alone, because both are positioned for **multi-tenant / service-provider** deployments.[4][5][6]

- **FusionPBX** is described as the choice for **service providers, MSPs, and enterprises that need to host multiple organizations on shared infrastructure**.[5]
- **ICTPBX** is described as **native multi-tenant** and **white-label**, and specifically aimed at **ITSPs, MSPs, and hosted voice resellers**.[4]
- **FreePBX** is strongly suited to **single-business** or standard office deployments, but one guide explicitly says its multi-tenant support is only a workaround and recommends it mainly for single-business use.[2][4][5][6]

If you want a practical recommendation:
- Choose **ICTPBX** if you want the most directly aligned **hosted voice / reseller / white-label** product out of the box.[4]
- Choose **FusionPBX** if you want a more established **multi-tenant PBX stack** built on **FreeSWITCH**.[5][6]
- Choose **Asterisk + FreePBX** only if you are building a **single-customer PBX** or are willing to engineer the multi-tenant layer yourself.[2][4][5][12]

For an ISP, the main decision is usually not just “PBX software” but whether you need:
- **Tenant isolation**
- **Per-customer branding / portals**
- **Provisioning automation**
- **Role-based admin access**
- **Billing integration**
- **Scalability for many separate customers**

The sources you provided point most strongly to **ICTPBX** and **FusionPBX** for that use case.[4][5][6]

If you want, I can also give you a **shortlist by architecture**:
- **best for quickest launch**
- **best for maximum control**
- **best for largest scale**
- **best for lowest ops burden**


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

For a **support team** that wants an open-source PBX with **built-in queue management**, **FreePBX** is the strongest default choice. It includes a **Queues** module for ACD-style inbound routing with agent login/logout, round-robin or least-recent distribution, announcements, and basic queue statistics.[1][9][15]

If you need a more **contact-center-focused** platform rather than a general PBX, **VICIdial** is the best open-source option overall; it is described as purpose-built for contact center operations, especially when outbound dialing or campaign management matters.[1]

A practical shortlist looks like this:

- **FreePBX** — best for most support teams needing **inbound queues**, IVR, and easier admin on top of Asterisk.[1][2][8]
- **VICIdial** — best if you also need **predictive dialing**, campaigns, lead lists, and blended inbound/outbound workflows.[1]
- **FusionPBX** — viable if you want a web-managed PBX with queue support, but it is generally positioned behind FreePBX for simple support-center queue needs.[1][2]

If your requirement is specifically **“PBX + queues for support desk”**, FreePBX is usually the best fit because its queue module is well established and directly supports common helpdesk call-distribution patterns.[1][15]


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

The strongest **self-hosted open-source phone system** choices with active development and large community support are **Asterisk** and **FreePBX**; **FusionPBX** is also a solid option, and **Wazo** is worth considering if you want a more modern API-first platform.[9][14][1][7]

- **Asterisk**: the core telephony framework, described as a free and open-source communications platform with long-running continuous development and a broad community footprint.[14][4]
- **FreePBX**: a web-based management layer on top of Asterisk; it says it is the world’s most popular open source IP PBX and highlights a global developer community and very active development.[9][4]
- **FusionPBX**: a web interface for FreeSWITCH; community discussions describe it as very active on GitHub, and it remains a commonly recommended self-hosted PBX option.[1][10]
- **Wazo**: a modern, API-first unified communications platform built on Asterisk; it appears in current comparisons as a mature open-source PBX platform.[7]
- **FreeSWITCH**: not a complete PBX GUI by itself, but a widely used open-source telephony platform that often underpins PBX systems like FusionPBX.[10][13]

If you want the **most established ecosystem**, start with **Asterisk + FreePBX**.[9][14]
If you want a **FreeSWITCH-based stack**, look at **FusionPBX**.[1][10]
If you want something **more modern and API-oriented**, consider **Wazo**.[7]

If you want, I can also narrow this down by use case, such as **small business PBX**, **home lab**, or **call-center features**.


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

For a university deploying **campus extensions**, the best default open-source PBX choice is **FreePBX** on top of **Asterisk** because it is widely used, web-managed, and suited to in-house phone systems and education environments.[8][13][1]

If the university needs **multi-tenant administration** for separate departments, campuses, or service units, **FusionPBX** is the stronger fit because it is commonly recommended for hosted multi-tenant PBX deployments.[1][14]

A practical recommendation is:

- **Single campus / central IT-managed system:** **FreePBX + Asterisk**[8][13]
- **Multiple departments or campuses with shared infrastructure:** **FusionPBX**[1][14]
- **Custom telecom engineering or heavy scaling needs:** **raw Asterisk** or **FreeSWITCH** instead of a full PBX GUI[8][14]

If you want, I can also compare **FreePBX vs FusionPBX vs MikoPBX** specifically for university requirements like call routing, voicemail, auto-attendant, and multi-campus extension dialing.