Combining offices in 3CX (Part 3. Using Raspberry PI)

In a previous article, I promised to talk about an alternative to the SBC (Session Border Controller) from 3CX based on a single-board Raspberry PI computer.

Raspberry PI is a single-board (four-layer printed circuit board) computer the size of no more than a pack of cigarettes and is available in several versions:

• “A” (ARM1176JZ-F processor, 256 MB RAM, 26 GPIO pins, 1 USB port),
• “A +” (ARM1176JZ-F processor, 512 MB RAM, 40 GPIO pins, 1 USB port),
• “B” (ARM1176JZ-F processor, 512 MB RAM, 26 GPIO pins, 2 USB ports, with ethernet),
• “B +” (ARM1176JZ-F processor, 512 MB RAM, 40 GPIO pins, 4 USB ports, with ethernet),
• “2B” (Broadcom BCM2836 processor - 4 ARM Cortex-A7 cores, 1 GB RAM, 40 GPIO pins, 4 USB ports, with ethernet)

For our purposes, the minimum modification is modification “B” with support for Micro SD Card. But we would recommend Model 2B:



Our recommendations with regard to the load:

• Up to 5 simultaneous conversations - Raspberry PI 2 model B, the average cost on the Yandex market is ~ 3900 rubles
• Up to 15 simultaneous calls - Raspberry PI 2 model 2B, the average cost on the Yandex market is ~ 4,500 rubles

Installation and configuration The

hardware is configured in a couple of steps:

Step 1. Installing the operating system
At startup, a window appears with a choice of installations, we are interested in Raspbian OS:



After installing the OS, you will need access to SSH for further configuration (Default login / password: pi / password ).

Next, we connect via SSH (at boot, hold down the “Shift” button to enter “recovery mode”) - it is recommended to update the OS (update command: sudo apt-get update ).

Step 2. Installation and configuration of 3CX SBC
Download and install 3CX SBC (command: wget downloads.3cx.com/downloads/sbc/3cxsbc.zip ):



Install (command:sudo sh 3cxsbc.zip ):



After installation, you need to configure the configuration file (command: Sudo nano /etc/3cxsbc.conf ):

1. Specify a password for connecting to the tunnel (configured in the 3CX web interface: Settings / Security / 3CX tunnel, line)
2. Specify a port for the tunnel (configured in the 3CX web interface: Settings / Security / 3CX tunnel)
3. Specify a host name (configured in the 3CX web interface: Settings / Network / FQDN)
4. Specify SIP port (configurable in 3CX web interface: Settings / Network)

File Location Structure:

• /etc/3cxsbc.conf - configuration file,
• /var/log/3cxsbc.log - logging, disabled by default,
• / usr / sbin / 3cxsbc - executable file,
• /etc/init.d/3cxsbc - daemon.

And as a result, we get a working scheme:



As mentioned earlier, this scheme is suitable for merging offices, where there are no more than 15 simultaneous conversations. If more than 15 are required, then we recommend using the software application, which was described in the second part.

Note: the described recommendations are suitable for connecting to the latest version of 3CX Shone System v14 .

Part 1
Part 2