Install Issabel 5 on Rocky Linux 8: Simple Step-by-Step PBX Setup

This guide shows how to install Issabel 5 on Rocky Linux 8 and configure it for a small office phone system. Issabel is an open-source unified communications server built on Asterisk, forked from Elastix. It adds a web interface for extensions, trunks, IVRs, queues, voicemail and call recording, so you do not need to edit Asterisk configuration files by hand.

Short answer: Install Rocky Linux 8 minimal on a server with 2 vCPU, 4 GB RAM and 40 GB disk, give it a static IP, disable SELinux, then run yum -y install wget && wget -O - http://repo.issabel.org/issabel5-netinstall.sh | bash. When it finishes, open http://SERVER-IP, log in as admin, create extensions under PBX » PBX Configuration, add a SIP trunk and routes, and restrict SIP and RTP in the firewall.

Before you start

Issabel 5 targets Rocky Linux 8 (and compatible EL8 releases). Rocky Linux 8 receives updates until 2029. Development of Issabel is community-driven and slower than Asterisk itself, so check the project’s release notes before you commit a production site to it. If you prefer to work directly with Asterisk and configuration files, see the Asterisk 22 install guide instead.

Item	Suggested for up to about 50 extensions
CPU / RAM	2 vCPU, 4 GB RAM
Disk	40 GB; more if you record calls
OS	Rocky Linux 8 minimal, fully updated
Network	Static IP, correct hostname and DNS, internet access for the installer

Step 1: prepare Rocky Linux 8

dnf -y update
hostnamectl set-hostname pbx.example.com
timedatectl set-timezone Europe/London      # your time zone
getenforce

Issabel expects SELinux to be disabled. If getenforce shows Enforcing, change it and reboot:

sed -i 's/^SELINUX=.*/SELINUX=disabled/' /etc/selinux/config
reboot

Step 2: run the Issabel netinstall script

yum -y install wget
wget -O - http://repo.issabel.org/issabel5-netinstall.sh | bash

The script adds the Issabel repositories, installs Asterisk, the web interface, MariaDB and the supporting services, and may ask you to choose options and set passwords along the way. Answer the prompts, let it finish (10–30 minutes depending on the connection) and reboot when it tells you to. Read the script from the repository first if your policy requires reviewing anything piped to a shell.

Step 3: first login

Browse to http://SERVER-IP (or HTTPS once a certificate is in place) and log in as admin with the password you set. Then:

1. Open System » Network and confirm the IP, gateway, DNS and hostname.
2. Check System » Dashboard for any service that is not running.
3. Change any default or weak passwords, and create separate web users for staff instead of sharing admin.

Step 4: create extensions

Go to PBX » PBX Configuration » Extensions, choose PJSIP (or SIP on older builds) and add each user: extension number, display name and a long random secret. Enable voicemail if needed. Register a softphone or desk phone with the server IP, extension number and secret, and call between two extensions to test audio.

Step 5: SIP trunk and routes

1. Trunks » Add SIP/PJSIP trunk: enter the details from your SIP provider (server, username, password, registration string or IP authentication).
2. Outbound Routes: add dial patterns (for example your country’s national and international formats) and select the trunk.
3. Inbound Routes: map each DID from the provider to an extension, ring group, queue or IVR.
4. Click Apply Config after changes so they reach Asterisk.

If the office router has SIP ALG, disable it before testing external calls, and set the external IP and local networks in the PBX’s SIP/NAT settings.

Step 6: firewall, security and backups

Port	Protocol	Use	Allow from
22	TCP	SSH	Admin networks only
80, 443	TCP	Web interface	Admin and office networks only
5060	UDP	SIP signalling	Office, remote phones, SIP provider
10000–20000	UDP	RTP media	Any (required for audio)

Use Issabel’s built-in firewall (Security » Firewall) or firewalld to apply these rules, and enable fail2ban for SIP registrations. Then schedule backups under System » Backup/Restore, copy them off the server, and keep the OS up to date with dnf -y update during a maintenance window.

Install Issabel 5 at a glance

Official documentation: Issabel project, Rocky Linux documentation.

Related guides: Install Asterisk 22 LTS on Debian 13 · SIP ports and firewall rules · Disable SIP ALG on your router.

Frequently asked questions