The Raspberry Pi is one of the most flexible pieces of hardware of the recent years detonating a full revolution within the “makers” communities around the world. Thanks to its versatility it can be used as a video game console or a weather station. With dimensions barely larger than a credit card, the Raspberry Pi is probably one of the smallest and at the same time cheapest computers currently on the market.

The new version, the Raspberry Pi 3B+ is powered with a 1.4GHz 64 bits quadcore processor, Wireless LAN, Bluetooth 4.2/BLE and Ethernet interface. Its potential is just awesome. A thousand of Raspberry Pi projects can be found on the internet and in this article we’re going to explain how we can use the Raspberry Pi to install a fully operational IP PBX, useful for different scenarios, like:

Micro and small size enterprises

Small Office Home Offices (SoHo)

Remote or branch offices

Hotels with a high number of rooms but a few ongoing calls

Intercom for condo’s

Schools

Telephony Laboratory

As part of a Disaster Recovery Plan

Requeriments to install our IP PBX on a Raspberry Pi

Installing our IP PBX on a Raspberry Pi is fairly straight forward and we will only need:

Raspberry Pi 3B+

32+GB Class 10 Micro SD

Raspberry Pi compatible case preferably with heatsink(s) and cooling fan

Raspberry Pi compatible 2.5 Amp Micro USB power supply

Preparing the MicroSD card and installing your IP PBX

First we need to prepare the MicroSD, to do so with need to download the Raspbian Stretch image from here and then follow the steps on this video:

Recomendations

Based on our tests the Raspberry Pi 3B+ is ideal to handle up to 8 simultaneous calls

Disable the log or set in on “Low” to minimize bottlenecks

Disable the recording in order to maximize storage performance

Use a capable Class 10 Micro SD with >=10MB/s sustained transfer speed

Avoid using OPUS codec to reduce the CPU load and increase thermal efficiency

For detailed instructions read the PBX on Raspberry Pi install guide.