Kamailio

The open-source SIP server for large real-time communication services

About Kamailio

Kamailio is a free, open-source SIP server used to build large-scale VoIP and real-time communication platforms. Written in C for speed, it can act as a SIP proxy, registrar, location, presence, application or dispatcher server, handling thousands of call setups per second with a flexible routing language and hundreds of modules. Released under the GPL, Kamailio powers carrier and enterprise telephony worldwide and is aimed at operators and engineers building serious SIP infrastructure.

Kamailio website preview

Live preview of kamailio.org via the WordPress mShots service — it can take a few seconds to generate on a first visit.

Kamailio: strengths & things to check

Strengths

Completely free to use — this directory lists no paid plan for it.
Covers sip, voip, telephony, server — see the focus areas listed in its key facts.
Has 6 close alternatives in the same category on this page, so switching or comparing is easy.

Things to check

Free tools can change their model or shut down — avoid locking critical work into it without an export path.
Current plan prices are not listed here (they change too often to print reliably) — confirm the exact price on the official site.
It is one of 565 tools in the Communication & Collaboration category here — compare it against the alternatives below before you commit.

Derived from this listing's own data (pricing model, focus areas and category) — not a hands-on review score.

Kamailio pricing

Pricing model	Free — listed in this directory as a free tool, with no paid plan required to use it.
Free access	Yes — fully free
Current plan prices	Listed on the official site — prices change, so this directory links out instead of printing a number that may already be stale.
Official site	kamailio.org

Kamailio key facts

Category: Communication & Collaboration
Pricing: Free — listed in this directory as a free tool, with no paid plan required to use it.
Focus areas: sip, voip, telephony, server
Official site: kamailio.org

Kamailio FAQ

How much does Kamailio cost?

Free — listed in this directory as a free tool, with no paid plan required to use it. Current plans and prices are listed on the official site (kamailio.org).

What is Kamailio used for?

The open-source SIP server for large real-time communication services Its focus areas in the Communication & Collaboration category: sip, voip, telephony, server.

Where can I try Kamailio?

On its official site, kamailio.org — the Visit Official Site button above goes straight there.

Kamailio vs alternatives

	Kamailio	OpenSIPS	Asterisk	FreeSWITCH
Pricing	Free — listed in this directory as a free tool, with no paid plan required to use it.	Free — listed in this directory as a free tool, with no paid plan required to use it.	Free — listed in this directory as a free tool, with no paid plan required to use it.	Freemium — a free tier lets you start, and paid plans are available if you need more.
Focus areas	sip, voip, telephony, server	sip, voip, telephony, open source, server	voip, pbx, sip, telephony, open source	telephony, voip, open source, sip, self hosted
Official site	kamailio.org	opensips.org	asterisk.org	freeswitch.org
Directory status	Listed	Listed	Listed	Listed

Side-by-side from each listing's own directory data. Full alternative cards are below.

About the Communication & Collaboration category

Chat, video meetings, and messaging apps that keep teams connected. The Communication & Collaboration category on Tools Hub currently lists 565 tools. Alongside Kamailio, it includes Yeti Switch, Artalk, Coral, Friendica.

FreeCommunication & Collaborationsipvoiptelephonyserver

Alternatives to Kamailio

Tools in the same Communication & Collaboration category that share focus areas with Kamailio — worth comparing before you commit:

Communication & Collaboration

OpenSIPS

Open-source SIP proxy and server for voice and video

Freesipvoiptelephonyopen-source

Communication & Collaboration

Asterisk

Open-source IP PBX, VoIP gateway and conference server framework

Freevoippbxsiptelephony

Communication & Collaboration

FreeSWITCH

Open-source telephony platform for real-time voice and video

Freemiumtelephonyvoipopen-sourcesip

Communication & Collaboration

Anveo

VoIP platform with visual call flow builder

Freemiumvoipivrsipcall-flow

Communication & Collaboration

Callcentric

BYOD VoIP service with pay-per-minute plans

Freemiumvoipsipbyodtrunking

Communication & Collaboration

FreePBX

Web-based open-source GUI for managing Asterisk phone systems

Freepbxvoipasterisktelephony

More in Communication & Collaboration

Comparing tools in the Communication & Collaboration category? These related listings are worth a look: Yeti Switch — Open-source SIP softswitch, session border controller and VoIP billing system; Artalk — A self-hosted comment system for blogs, websites and web applications; Coral — A better commenting experience, from Vox Media.