Install Kamailio SIP Server on CentOS 8 / CentOS 7

This guide will help you to install Latest Kamailio SIP Server on CentOS 7 / CentOS 8 Linux server. This is part of Series tutorials on Building an Enterprise VOIP System. Kamailio is a distribution of SER and provides a scalable SIP server suitable for small through to carrier grade installations.

Features of Kamailio SIP Server

Kamailio’s main advantages for use alongside Media server like Asterisk are:

• Kamailio can handle over 5000 call setups per second.
• Can serve up to 300,000 active subscribers with just a 4GB Ram System.
• Clustering can easily be realized by adding more Kamailio servers

Kamailio can function as:
● Registrar server
● Location server
● Proxy server
● SIP Application server
● Redirect server

Other Features of Kamailio are:

• NAT traversal support for SIP and RTP traffic
• Load balancing with many distribution algorithms and
  failover support
• Provides flexible least cost routing
• Easy to realize routing failover
• Support both IPv4 and IPv6
• SCTP multi-homing and multi-streaming
• Communication can be over UDP, TCP, TLS, and SCTP
• Digest SIP User authentication
• Provides event-based accounting
• Data storage can be to database, Radius or Diameter
• Extensible Java, Python, Lua and Perl Programming interface
• TLS support for SIP signaling and transparent handling of SRTP for secure audio

We have tested this guide on:

• Kamailio 5.x
• CentOS 7 / CentOS 8

Install Kamailio SIP Server on CentOS 7 / CentOS 8

Before we dive deep into the installation process, let’s get some heads up on basics about Kamailio SIP Server.

1. Set SELinux mode

If you’re not SELinux lover, I recommend you put it in Permissive mode:

sudo setenforce 0
sudo sed -i 's/^SELINUX=.*/SELINUX=permissive/g' /etc/selinux/config

If you decide to permanently disable it, you’ll need to reboot your  CentOS system:

sudo setenforce 0
sudo sed -i 's/^SELINUX=.*/SELINUX=disabled/g' /etc/selinux/config
sudo reboot

After rebooting, confirm SELinux status:

$ sestatus 
SELinux status: enabled
SELinuxfs mount: /sys/fs/selinux
SELinux root directory: /etc/selinux
Loaded policy name: targeted
Current mode: permissive
Mode from config file: enforcing
Policy MLS status: enabled
Policy deny_unknown status: allowed
Max kernel policy version: 31

2. Install MariaDB Database server

Kamailio requires a database server to function. For this, we’ll use the MariaDB database server which can be installed on CentOS 7 / CentOS 8:

sudo yum -y install mariadb-server
sudo systemctl enable --now mariadb
sudo mysql_secure_installation

3. Add Kamailio RPM Repository

CentOS 8:

Add Kamailio YUM repository on your CentOS 8 by running the following commands:

sudo yum -y install dnf-plugins-core
sudo yum config-manager --add-repo https://rpm.kamailio.org/centos/kamailio.repo

CentOS 7:

On CentOS 7, enable Kamailio RPM repository by running the following commands:

sudo yum -y install yum-utils
sudo yum-config-manager --add-repo https://rpm.kamailio.org/centos/kamailio.repo

4. Install Kamailio SIP Server

Once the repository is added, install Kamailio SIP Server on CentOS 8 / CentOS 7 Linux.

sudo yum install vim kamailio kamailio-presence kamailio-ldap kamailio-mysql kamailio-debuginfo kamailio-xmpp kamailio-unixodbc kamailio-utils kamailio-tls kamailio-outbound kamailio-gzcompress

Dependency tree should be shown nd you can hit th y key in your keyboard to begin installation.

...
Transaction Summary
======================================================================================================================================================================================================
Install  17 Packages
Upgrade   2 Packages

Total download size: 25 M
Is this ok [y/N]: y

Confirm installed Kamailio version:

$ kamailio -version
version: kamailio 5.5.2 (x86_64/linux) 55e232
flags: USE_TCP, USE_TLS, USE_SCTP, TLS_HOOKS, USE_RAW_SOCKS, DISABLE_NAGLE, USE_MCAST, DNS_IP_HACK, SHM_MMAP, PKG_MALLOC, Q_MALLOC, F_MALLOC, TLSF_MALLOC, DBG_SR_MEMORY, USE_FUTEX, FAST_LOCK-ADAPTIVE_WAIT, USE_DNS_CACHE, USE_DNS_FAILOVER, USE_NAPTR, USE_DST_BLOCKLIST, HAVE_RESOLV_RES, TLS_PTHREAD_MUTEX_SHARED
ADAPTIVE_WAIT_LOOPS 1024, MAX_RECV_BUFFER_SIZE 262144, MAX_URI_SIZE 1024, BUF_SIZE 65535, DEFAULT PKG_SIZE 8MB
poll method support: poll, epoll_lt, epoll_et, sigio_rt, select.
id: 55e232
compiled on 14:13:04 Aug 25 2021 with gcc 8.4.1

5. Configure Kamailio Server

Edit the file /etc/kamailio/kamctlrc  and make sure the DBENGINE variable is set to MySQL. Remove the pound symbol to uncomment it.

sudo vi /etc/kamailio/kamctlrc

Set Database engine to MYSQL

DBENGINE=MYSQL
DBHOST=localhost

Run the command below to create users and tables needed by Kamailio ( Schema).

$ sudo kamdbctl create
MySQL password for root:
INFO: test server charset
INFO: creating database kamailio …
INFO: granting privileges to database kamailio …
INFO: creating standard tables into kamailio …
INFO: Core Kamailio tables succesfully created.
Install presence related tables? (y/n): y
INFO: creating presence tables into kamailio …
INFO: Presence tables succesfully created.
Install tables for imc cpl siptrace domainpolicy carrierroute
drouting userblacklist htable purple uac pipelimit mtree sca mohqueue
rtpproxy rtpengine secfilter? (y/n): y
INFO: creating extra tables into kamailio …
INFO: Extra tables succesfully created.
Install tables for uid_auth_db uid_avp_db uid_domain uid_gflags
uid_uri_db? (y/n): y
INFO: creating uid tables into kamailio …
INFO: UID tables succesfully created.

When asked for root password, enter the MySQL root user password as configured through mysql_secure_installation

Answer Yes to all the questions that follow. The kamdbctl create command will add two Mysql users:

• kamailio: With the password.kamailiorw It has read/write access permissions to the Kamailio database.
• kamailioro: The password for this user is kamailioro. It has read-only access permissions to the Kamailio database.

Next is to edit /etc/kamailio/kamailio.cfg to configure Kamailio:

sudo vi /etc/kamailio/kamailio.cfg

Add the following lines just below #!KAMAILIO.

#!define WITH_MYSQL
#!define WITH_AUTH
#!define WITH_USRLOCDB
#!define WITH_NAT
#!define WITH_PRESENCE
#!define WITH_ACCDB

Start Kamailio

sudo systemctl restart kamailio

Enable the service to start on boot:

sudo systemctl enable kamailio

That’s the end. You should now have a running Kamailio SIP server on your CentOS 8 / CentOS 7 Linux.

$ systemctl status kamailio
● kamailio.service - Kamailio (OpenSER) - the Open Source SIP Server
   Loaded: loaded (/usr/lib/systemd/system/kamailio.service; enabled; vendor preset: disabled)
   Active: active (running) since Sun 2020-05-03 16:35:23 EAT; 12s ago
 Main PID: 9648 (kamailio)
    Tasks: 41 (limit: 24003)
   Memory: 50.0M
   CGroup: /system.slice/kamailio.service
           ├─9648 /usr/sbin/kamailio -DD -P /var/run/kamailio/kamailio.pid -f /etc/kamailio/kamailio.cfg -m 64 -M 4
           ├─9649 /usr/sbin/kamailio -DD -P /var/run/kamailio/kamailio.pid -f /etc/kamailio/kamailio.cfg -m 64 -M 4
           ├─9650 /usr/sbin/kamailio -DD -P /var/run/kamailio/kamailio.pid -f /etc/kamailio/kamailio.cfg -m 64 -M 4
           ├─9651 /usr/sbin/kamailio -DD -P /var/run/kamailio/kamailio.pid -f /etc/kamailio/kamailio.cfg -m 64 -M 4
           ├─9652 /usr/sbin/kamailio -DD -P /var/run/kamailio/kamailio.pid -f /etc/kamailio/kamailio.cfg -m 64 -M 4
           ├─9653 /usr/sbin/kamailio -DD -P /var/run/kamailio/kamailio.pid -f /etc/kamailio/kamailio.cfg -m 64 -M 4
           ├─9654 /usr/sbin/kamailio -DD -P /var/run/kamailio/kamailio.pid -f /etc/kamailio/kamailio.cfg -m 64 -M 4
           ├─9655 /usr/sbin/kamailio -DD -P /var/run/kamailio/kamailio.pid -f /etc/kamailio/kamailio.cfg -m 64 -M 4
           ├─9656 /usr/sbin/kamailio -DD -P /var/run/kamailio/kamailio.pid -f /etc/kamailio/kamailio.cfg -m 64 -M 4
           ├─9658 /usr/sbin/kamailio -DD -P /var/run/kamailio/kamailio.pid -f /etc/kamailio/kamailio.cfg -m 64 -M 4
           ├─9659 /usr/sbin/kamailio -DD -P /var/run/kamailio/kamailio.pid -f /etc/kamailio/kamailio.cfg -m 64 -M 4
......

Other guides:

• Install Asterisk PBX on CentOS 8
• Install Asterisk PBX on CentOS 7