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Module 15 of 16 · 📖 5 min read · ⏱ 60 min total

FUTO 15 FreePBX Telefonanlage (EN)

Table of contents (6 sections)
  1. Concepts and Background
  2. Architecture Diagram
  3. Practical Steps
  4. Common Pitfalls
  5. Further Resources
  6. Knowledge Check

Module: FUTO 15 FreePBX Telephone System

In this module, you will learn how to set up and configure a full-fledged VoIP telephone system with FreePBX. You will learn how to set up SIP trunks for connecting to the public telephone network, manage internal extensions (phone numbers), set up voicemail boxes, and create simple Interactive Voice Response (IVR) menus. At the end of this module, you will be able to host and manage a professional telephone solution for your company yourself.

FreePBX is based on the open-source telephone server Asterisk and provides a web-based interface for configuration. You will learn the basic architecture of a VoIP system and receive practical guides for setup and troubleshooting. This module is aimed at IT administrators in small businesses and self-employed individuals who want to control their telephony infrastructure themselves and save costs.

Concepts and Background

FreePBX
A web-based configuration interface for Asterisk that simplifies the management of a telephone system. FreePBX offers modules for almost all common telephony functions and is the de-facto standard solution for Asterisk-based systems.
Asterisk
The open-source telephony engine that runs in the background of FreePBX. Asterisk implements the SIP protocol for VoIP, manages call routing, and provides the basic functionality of the telephone system.
SIP-Trunk
A virtual telephone line that connects your company to the public telephone network. Via a SIP trunk, you can receive and make calls from the landline or mobile network without physical ISDN lines.
Extensions
Internal phone numbers in your system. Each extension can be assigned to a physical phone (hardphone), a softphone application, or a group and serves as an access point for internal and external calls.
IVR (Interactive Voice Response)
Automated menus that guide callers through voice prompts and keypad inputs through a selection of options. IVRs help in distributing calls to the right departments or employees.

Architecture Diagram

flowchart LR
  A[Internet] --> B(Firewall/Router)
  B --> C[FreePBX Server]
  C --> D[IP-Phones/Softphones]
  B --> E[SIP-Trunk Provider]
  C --> F[Voicemail-System]

Practical Steps

  1. Install Ubuntu Server 22.04 LTS on your system. Reason: Ubuntu is the recommended base for FreePBX and provides stable package sources and long support cycles.
  2. Run the FreePBX Installer with the command 
    cd /tmp && wget http://mirror.freepbx.org/modules/installer/installer
    Reason: The official installer automates the installation of Apache, PHP, MySQL, and Asterisk.
  3. Configure your network card with a static IP address in the LAN range. Reason: The telephone system requires a fixed IP address for access via the local network and for SIP communication.
  4. Install FreePBX with 
    chmod +x installer && ./installer
    and follow the on-screen instructions. Reason: The installer correctly sets up all necessary services and dependencies.
  5. Log in to the FreePBX web interface at http://Your-IP-Address/admin and create an administrator user. Reason: A secure username and password are required to access the configuration.
  6. Set up a new SIP trunk for your provider under "Connectivity → Trunks". Reason: The trunk connects your system to the public telephone network.
  7. Create new internal phone numbers for your employees under "Applications → Extensions". Reason: Extensions are the basis for internal and external communication in your system.
  8. Configure voicemail for each extension under "Applications → Voicemail". Reason: Voicemail allows callers to leave messages when you are unavailable.
  9. Create a simple IVR menu under "Applications → IVR". Reason: IVRs improve the availability of your employees through automatic call distribution.
  10. Test the configuration by making an internal call between two extensions. Reason: The test ensures that the basic functionality of your system works correctly.

Common Pitfalls

Further Resources

Knowledge Check

Four questions for self-assessment. Click on each question to see the correct answer and explanation.

What is the main function of FreePBX in a VoIP telephone system?
  • A) The implementation of the SIP protocol for VoIP connections
  • B) A web-based configuration interface for Asterisk
  • C) The provision of physical telephone hardware
  • D) Establishing the connection to the public telephone network

Correct Answer: B. FreePBX is a web-based configuration interface for Asterisk that simplifies management. Option A describes the function of Asterisk, not FreePBX. Option C is incorrect because FreePBX is software, not hardware. Option D is implemented by SIP trunks, not by FreePBX.

What is a SIP trunk in the context of a FreePBX system?
  • A) An internal phone number in your system
  • B) A virtual connection to connect to the public telephone network
  • C) A module for creating IVR menus
  • D) A physical cable for connecting phones

Correct Answer: B. A SIP trunk is a virtual telephone line that connects your company with the public telephone network. Option A describes an extension, not a SIP trunk. Option C refers to the IVR module, not a SIP trunk. Option D is incorrect because SIP trunks are virtual, not physical connections.