How to Install Kamailio SIP Server on Debian 12

What is Kamailio?

Kamailio is a robust, high-performance SIP (Session Initiation Protocol) server used for managing and routing SIP signaling in VoIP (Voice over IP), video, and real-time communication systems. It is open-source and designed for carrier-grade scalability, capable of handling tens of thousands of concurrent calls per second.

Running Kamailio on Debian 12 (Bookworm) is an excellent choice for organizations and developers building scalable, secure, and customizable communication infrastructure.

Core Features of Kamailio

SIP Proxy and Registrar

Acts as a SIP proxy, location server, redirect server, and registrar.
Manages SIP registration, authentication, call routing, and forwarding.

High Scalability and Performance

Optimized to serve large-scale SIP networks with high throughput.
Efficient memory usage and support for multi-threading and clustering.

NAT Traversal Support

Handles clients behind NAT using RTPProxy, MediaProxy, STUN, or ICE.
Ensures SIP and media flow even in complex network environments.

Flexible Routing Logic

Powerful built-in configuration language and support for KEMI (Kamailio Embedded Interface) using languages like Lua, Python, and JavaScript.
Enables advanced SIP routing and decision-making.

Security and Access Control

Supports TLS encryption, digest authentication, IP filtering, and DoS protection.
Can integrate with fail2ban, firewalls, and third-party authentication systems.

Database and Backend Integration

Connects to MySQL, MariaDB, PostgreSQL, Redis, and SQLite.
Used for user location, accounting, call detail records, and routing logic.

WebRTC Support

WebSocket and TLS modules enable WebRTC signaling, useful for browsers and mobile clients.
Often paired with RTPEngine or Janus for media handling.

Load Balancing and High Availability

Features like dispatcher module and clustering make it suitable for load balancing and distributed setups.
Can be used as a front-end SIP router for Asterisk, FreeSWITCH, or other backends.

Why Use Kamailio on Debian 12?

Debian 12 is known for its stability, security, and long-term support, making it an ideal platform for deploying Kamailio in production environments.

Benefits include:

Lightweight and clean base system
Reliable performance on physical and virtual servers
Access to up-to-date SIP modules and security patches
Well-supported via Debian’s and Kamailio’s active communities

System Requirements for Kamailio on Debian 12

Component	Minimum Requirement
OS	Debian 12 (Bookworm)
CPU	1+ core (multi-core for high performance)
RAM	512 MB (2 GB or more recommended)
Disk	~200 MB (more for logs and media relays)
Network Ports	5060/UDP, 5060/TCP, 5061/TLS (SIP), plus RTP relay ports
Dependencies	`libssl`, `libmysqlclient`, `libpcre`, `systemd`

Kamailio handles signaling only, not media. For RTP streams, use RTPEngine, RTPProxy, or similar.

Common Use Cases

SIP trunking gateway for ITSPs and enterprises
SIP proxy front-end for PBX systems like Asterisk or FreeSWITCH
VoIP load balancer for large deployments
WebRTC signaling gateway
IMS Core component for telecom environments
Real-time communication backend for custom applications

Kamailio vs Other SIP Platforms

Feature	Kamailio	OpenSIPS	Asterisk	FreeSWITCH
SIP Proxy Function	Yes	Yes	Partial	Partial
Media Handling	No	No	Yes	Yes
Performance	Very High	Very High	Moderate	Moderate
WebRTC Support	Yes	Yes	Limited	Yes
Routing Flexibility	Very High	Very High	Moderate	High
Scalability	Carrier-grade	Carrier-grade	Limited	Limited
Target Use Case	SIP signaling, routing	Similar	Full PBX	Multimedia/VoIP apps

Security Considerations

Enable TLS for encrypted SIP signaling
Restrict access via firewall rules (iptables, nftables, ufw)
Implement rate limiting and fail2ban to block brute-force attacks
Use digest authentication, and optionally integrate with RADIUS or LDAP
Secure external modules and protect the configuration directory

Pros of Kamailio on Debian 12

Highly scalable and efficient signaling engine
Modular and extensible via scripting or KEMI APIs
Runs well on low-resource servers or high-availability clusters
Active community and long-term Debian compatibility
Ideal for carrier-grade VoIP infrastructure

Cons

No media support out of the box (requires external tools)
Steep learning curve for new users
Configuration file syntax can be complex for beginners
Requires understanding of SIP/RTP protocols and VoIP architecture

Kamailio SIP Server on Debian 12 is an exceptional choice for building custom, scalable, and secure VoIP infrastructure. Its performance and flexibility make it a preferred solution for service providers, telecom operators, and developers who require robust signaling capabilities and integration with other systems like Asterisk, FreeSWITCH, or WebRTC.

With Debian 12’s reliability and Kamailio’s feature-rich architecture, you can confidently deploy everything from simple SIP proxies to complex, multi-node, carrier-grade communication platforms.

Step 1: Create a Cloud VPS on Shape.Host

Go to https://shape.host and log in.

Click Create.

Choose Instance.

Select your preferred server location.

Choose Debian 12 (64-bit) as your OS.

Pick a plan with at least 2 CPUs, 4 GB RAM, and 20 GB SSD.

Click Create Instance.

Find your instance’s IP address under the Resources section.

Step 2: Connect to Your Server

Linux/macOS:
Open Terminal and run:

ssh root@your_server_ip

Windows:
Use PuTTY:

Host: your_server_ip
Port: 22, Type: SSH
Log in as root when prompted.

Step 3: Update Package Index

apt update

This refreshes your system’s list of available packages.

Step 4: Install MariaDB and GnuPG

apt install mariadb-server
apt install -y gnupg

MariaDB is used as Kamailio’s database backend. GnuPG is needed for verifying package keys.

Step 5: Add Kamailio’s GPG Key

wget -O /usr/share/keyrings/kamailio.gpg https://deb.kamailio.org/kamailiodebkey.gpg

This key allows your system to trust packages from the Kamailio repository.

Step 6: Add the Kamailio Repository

tee /etc/apt/sources.list.d/kamailio.list<<EOF
deb     http://deb.kamailio.org/kamailio60 noble main
deb-src http://deb.kamailio.org/kamailio60 noble main
EOF

Adds Kamailio 6.0 packages (for Ubuntu Noble, also compatible with Debian 12).

Step 7: Update Again for Kamailio Packages

apt update

This pulls in the Kamailio packages from the new repo.

Step 8: Install Kamailio and Required Modules

apt install kamailio kamailio-mysql-modules kamailio-websocket-modules kamailio-tls-modules

Installs the core SIP server and modules for MySQL, WebSocket, and TLS support.

Step 9: Verify Kamailio Version

kamailio -V

Confirms Kamailio was installed successfully and shows its version.

Step 10: Configure Kamailio Controller

nano /etc/kamailio/kamctlrc

Update or add these lines:

SIP_DOMAIN=srv1.example.com
DBENGINE=MYSQL
DBHOST=localhost

SIP_DOMAIN is the domain or hostname of your server.
DBENGINE tells Kamailio to use MySQL.
DBHOST should remain localhost if the database is on the same machine.

Step 11: Initialize the Database

kamdbctl create

This sets up the required Kamailio tables inside your MariaDB server.

Step 12: Enable Core Features in Config

nano /etc/kamailio/kamailio.cfg

Just below #!KAMAILIO, add:

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

This enables support for MySQL, user authentication, SIP user location, and accounting.

Step 13: Restart Kamailio

systemctl restart kamailio

Applies your changes and starts the Kamailio SIP service.

Step 14: Check Kamailio Status

systemctl status kamailio

Make sure the service is running without errors.

You now have Kamailio SIP Server running on Debian 12, with MySQL, authentication, and WebSocket/TLS modules ready for use.

This setup runs best on a reliable Cloud VPS from Shape.Host, with:

Instant instance creation
Full root access
Fast, scalable hosting ideal for VoIP and real-time apps

Start building your SIP infrastructure today at https://shape.host

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