How to Deploy Kamailio on Ubuntu VPS

This article provides a guide demonstrating how to deploy Kamailio on Ubuntu VPS.

Kamailio is a high-performance SIP (Session Initiation Protocol) server used for VoIP infrastructures, SIP trunking, IMS deployments, SBCs, and large-scale telecommunications platforms. It can handle thousands of concurrent calls while maintaining low resource usage.

This guide demonstrates how to deploy Kamailio 6.x on an Ubuntu VPS using the official Kamailio repositories.

Prerequisites

Before attempting to deploy Kamailio on Ubuntu VPS, ensure you have:

• Ubuntu 22.04 or Ubuntu 24.04 VPS
• Root or sudo access
• Public IP address
• Minimum:
  • 2 GB RAM
  • 2 CPU cores
  • 20 GB storage
  • Firewall access to open SIP ports

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How to Deploy Kamailio on Ubuntu VPS

To deploy Kamailio on Ubuntu VPS, follow the steps outlined below:

1. Update the Server

   Update all installed packages:

   sudo apt update
   sudo apt upgrade -y
   

   Install required utilities:

   sudo apt install -y curl gnupg2 wget
   

2. Add the Official Kamailio Repository

   Import the Kamailio repository signing key:

   curl -fsSL https://deb.kamailio.org/kamailiodebkey.gpg | \
   sudo gpg --dearmor -o /usr/share/keyrings/kamailio.gpg
   

   For Ubuntu 24.04 (Noble):

   echo "deb [signed-by=/usr/share/keyrings/kamailio.gpg] https://deb.kamailio.org/kamailio60 noble main" | \
   sudo tee /etc/apt/sources.list.d/kamailio.list
   

   For Ubuntu 22.04 (Jammy):

   echo "deb [signed-by=/usr/share/keyrings/kamailio.gpg] https://deb.kamailio.org/kamailio60 jammy main" | \
   sudo tee /etc/apt/sources.list.d/kamailio.list
   

   The Kamailio project maintains official repositories for Kamailio 6.x releases on Ubuntu and Debian systems.

   Update package indexes:

   sudo apt update
   

3. Install Kamailio 6

   Install the core package:

   sudo apt install -y kamailio
   

   Verify installation:

   kamailio -V
   

   Example output:

   version: kamailio 6.0.x
   

4. Install Useful Kamailio Modules

   For most production deployments, install additional modules:

   sudo apt install -y \
   kamailio-mysql-modules \
   kamailio-tls-modules \
   kamailio-websocket-modules \
   kamailio-utils-modules
   

   These modules provide:

   Module	Purpose
   MySQL	User authentication and location storage
   TLS	Secure SIP over TLS
   WebSocket	WebRTC support
   Utils	Administrative tools

5. Configure Firewall

   Open SIP ports:

   sudo ufw allow 5060/udp
   sudo ufw allow 5060/tcp
   sudo ufw allow 5061/tcp
   

   Enable firewall:

   sudo ufw enable
   

   Verify:

   sudo ufw status
   

6. Configure Kamailio

   Backup the default configuration:

   sudo cp /etc/kamailio/kamailio.cfg \
   /etc/kamailio/kamailio.cfg.backup
   

   Edit configuration:

   sudo nano /etc/kamailio/kamailio.cfg
   

   Locate the listening directive and configure your VPS IP:

   listen=udp:YOUR_SERVER_IP:5060
   

   Example:

   listen=udp:203.0.113.10:5060
   

   Set server alias:

   alias="sip.example.com"
   

   Replace with your actual domain.

7. Enable Database Support (Optional)

   Install MariaDB:

   sudo apt install -y mariadb-server
   

   Secure database:

   sudo mysql_secure_installation
   

   Edit Kamailio database settings:

   sudo nano /etc/kamailio/kamctlrc
   

   Configure:

   DBENGINE=MYSQL
   DBHOST=localhost
   SIP_DOMAIN=sip.example.com
   

   Create Kamailio database:

   sudo kamdbctl create
   

   Follow the prompts to create:

   • Database
   • Tables
   • Permissions

   Database-backed deployments are commonly used for subscriber authentication, registration storage, and accounting.

8. Enable Authentication Modules

   Open:

   sudo nano /etc/kamailio/kamailio.cfg
   

   Enable the following definitions near the top:

   #!define WITH_MYSQL
   #!define WITH_AUTH
   #!define WITH_USRLOCDB
   #!define WITH_ACCDB
   

   These enable:

   • Database storage
   • SIP authentication
   • User location services
   • Call accounting

9. Validate Configuration

   Before restarting Kamailio:

   sudo kamailio -c
   

   Expected result:

   configuration file OK
   

   Fix any reported syntax errors before proceeding.

10. Start Kamailio

    Enable service at boot:

    sudo systemctl enable kamailio
    

    Start service:

    sudo systemctl start kamailio
    

    Check status:

    sudo systemctl status kamailio
    

    You should see:

    Active: active (running)
    

    Kamailio includes native systemd service files for modern Ubuntu deployments.

11. Create a SIP User

    Add a SIP account:

    sudo kamctl add testuser password123
    

    Verify:

    sudo kamctl ul show
    

12. Test SIP Registration

    Configure a SIP softphone such as:

    • Zoiper
    • Linphone
    • MicroSIP

    Use:

    Username: testuser
    Password: password123
    Domain: sip.example.com
    Port: 5060
    Transport: UDP
    

    Attempt registration.

    Monitor logs:

    sudo journalctl -u kamailio -f
    

13. Monitor SIP Traffic

    Install sngrep:

    sudo apt install -y sngrep
    

    Launch:

    sudo sngrep
    

    You can now watch:

    • REGISTER requests
    • INVITE messages
    • SIP responses
    • Call flows

14. Enable SIP over TLS

    TLS encrypts SIP signaling traffic, protecting registrations, authentication credentials, and call setup messages.

    Install TLS Modules

    sudo apt install -y kamailio-tls-modules openssl
    

    Create TLS Certificates

    For production, use Let’s Encrypt.

    Install Certbot:

    sudo apt install -y certbot
    

    Generate certificate:

    sudo certbot certonly --standalone -d sip.example.com
    

    Certificates will be stored in:

    /etc/letsencrypt/live/sip.example.com/
    

    Create Kamailio TLS Configuration

    Create:

    sudo nano /etc/kamailio/tls.cfg
    

    Example:

    [server:default]
    method = TLSv1.2+
    
    private_key = /etc/letsencrypt/live/sip.example.com/privkey.pem
    certificate = /etc/letsencrypt/live/sip.example.com/fullchain.pem
    ca_list = /etc/ssl/certs/ca-certificates.crt
    
    verify_certificate = no
    require_certificate = no
    

    Enable TLS in Kamailio

    Edit:

    sudo nano /etc/kamailio/kamailio.cfg
    

    Enable:

    #!define WITH_TLS
    

    Add TLS listener:

    listen=tls:YOUR_SERVER_IP:5061
    

    Load TLS module if not already loaded:

    loadmodule "tls.so"
    
    modparam("tls", "config", "/etc/kamailio/tls.cfg")
    

    Open Firewall

    sudo ufw allow 5061/tcp
    

    Validate Configuration

    sudo kamailio -c
    

    Restart Kamailio:

    sudo systemctl restart kamailio
    

    Verify:

    sudo ss -tlnp | grep 5061
    

    Expected:

    LISTEN 0 128 0.0.0.0:5061
    

    Configure Softphones

    Set:

    Transport: TLS
    Port: 5061
    

    You should now see TLS registrations in:

    sudo sngrep
    

15. Install and Configure RTPEngine

    RTPEngine provides media proxying for:

    • NAT traversal
    • SRTP support
    • WebRTC
    • Codec transcoding
    • RTP anchoring

    Install RTPEngine

    Ubuntu package:

    sudo apt install -y rtpengine
    

    Configure Kernel Module

    Load:

    sudo modprobe xt_RTPENGINE
    

    Verify:

    lsmod | grep RTPENGINE
    

    Configure RTPEngine

    Edit:

    sudo nano /etc/rtpengine/rtpengine.conf
    

    Example:

    [rtpengine]
    table = 0
    
    interface = public/YOUR_PUBLIC_IP
    
    listen-ng = 127.0.0.1:2223
    
    port-min = 10000
    port-max = 20000
    
    foreground = false
    

    Open RTP Ports

    sudo ufw allow 10000:20000/udp
    

    Start RTPEngine

    sudo systemctl enable rtpengine
    sudo systemctl restart rtpengine
    

    Verify:

    sudo systemctl status rtpengine
    

    Enable RTPEngine in Kamailio

    Install module:

    sudo apt install -y kamailio-extra-modules
    

    Verify:

    ls /usr/lib/x86_64-linux-gnu/kamailio/modules/rtpengine.so
    

    Add to kamailio.cfg:

    loadmodule "rtpengine.so"
    
    modparam("rtpengine",
        "rtpengine_sock",
        "udp:127.0.0.1:2223")
    

    Route SIP Traffic Through RTPEngine

    Inside request_route:

    if (is_method("INVITE")) {
        rtpengine_offer();
    }
    
    if (is_method("BYE")) {
        rtpengine_delete();
    }
    

    Inside onreply_route:

    if (status =~ "[12][0-9][0-9]") {
        rtpengine_answer();
    }
    

    Validate:

    sudo kamailio -c
    

    Restart:

    sudo systemctl restart kamailio
    

16. Configure SIP Load Balancing with Dispatcher

    Kamailio’s Dispatcher module allows SIP traffic distribution across multiple PBX servers.

    Example topology:

    Internet
         |
     Kamailio
         |
    +----+----+
    |         |
    Asterisk1 Asterisk2
    

    Install Dispatcher Module

    Usually included:

    sudo apt install -y kamailio
    

    Verify:

    find /usr -name dispatcher.so
    

    Enable Dispatcher

    Add:

    loadmodule "dispatcher.so"
    
    modparam("dispatcher",
             "list_file",
             "/etc/kamailio/dispatcher.list")
    

    Create Backend List

    sudo nano /etc/kamailio/dispatcher.list
    

    Example:

    1 sip:10.0.0.11:5060
    1 sip:10.0.0.12:5060
    1 sip:10.0.0.13:5060
    

    Group 1 contains three SIP servers.

    Configure Round-Robin Routing

    Add to request_route:

    if (is_method("INVITE")) {
    
        if (!ds_select_dst("1", "4")) {
            send_reply("500", "No Destination");
            exit;
        }
    
        t_relay();
        exit;
    }
    

    Dispatcher algorithm values:

    Value	Algorithm
    0	Hash Call-ID
    2	Hash From URI
    4	Round Robin
    8	Random
    10	Weight Based

    Recommended:

    ds_select_dst("1", "4")
    

    for even distribution.

    Enable Backend Health Checks

    Add:

    modparam("dispatcher", "ds_ping_interval", 30)
    modparam("dispatcher", "ds_probing_mode", 1)
    

    Kamailio will automatically probe servers and remove failed nodes from rotation.

    Reload Dispatcher Without Restart

    After editing dispatcher.list:

    kamcmd dispatcher.reload
    

    View status:

    kamcmd dispatcher.list
    

    Example:

    SET: 1
    sip:10.0.0.11:5060 ACTIVE
    sip:10.0.0.12:5060 ACTIVE
    sip:10.0.0.13:5060 ACTIVE
    

Recommended Production Architecture

                    Internet
                        |
                 TLS 5061 / UDP 5060
                        |
                +----------------+
                |    Kamailio    |
                | Load Balancer  |
                +----------------+
                        |
                  RTPEngine
                        |
        +---------------+---------------+
        |                               |
 +--------------+              +--------------+
 | Asterisk #1  |              | Asterisk #2  |
 +--------------+              +--------------+
        |                               |
     SIP Users                     SIP Users

This architecture provides:

• SIP over TLS encryption
• RTP media anchoring via RTPEngine
• NAT traversal
• SIP load balancing
• High availability
• Horizontal scaling for thousands of concurrent calls
• WebRTC readiness (when combined with WSS and SRTP)

Useful Commands

Restart Kamailio:

sudo systemctl restart kamailio

Reload configuration:

sudo kamcmd cfg.reload

Check running processes:

ps aux | grep kamailio

View logs:

sudo journalctl -u kamailio

Next Steps

Once Kamailio is running successfully, consider adding:

• • WebRTC support

• Dispatcher module
• Failover routing
• SBC functionality
• FreeSWITCH or Asterisk integration

These features transform Kamailio from a basic SIP proxy into a carrier-grade VoIP platform capable of handling large-scale deployments.

Conclusion

You now know how to deploy Kamailio on Ubuntu VPS.

Related:

• How to Install and Deploy FusionPBX on Debian VPS
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