Kamailio, formerly OpenSER (and sharing some common history with SIP Express Router (SER)), is a SIP server licensed under the GPL-2.0-or-later license. It can be configured to act as a SIP registrar, proxy or redirect server, and features presence support,

RADIUS In classical geometry, a radius ( : radii) of a circle or sphere is any of the line segments from its center to its perimeter, and in more modern usage, it is also their length. The name comes from the latin ''radius'', meaning ray but also the ...

syslog In computing, syslog is a standard for message logging. It allows separation of the software that generates messages, the system that stores them, and the software that reports and analyzes them. Each message is labeled with a facility code, i ...

accounting and authorization,

XML-RPC XML-RPC is a remote procedure call (RPC) protocol which uses XML to encode its calls and HTTP as a transport mechanism.Simon St. Laurent, Joe Johnston, Edd Dumbill. (June 2001) ''Programming Web Services with XML-RPC.'' O'Reilly. First Editi ...

and

JSON-RPC JSON-RPC is a remote procedure call protocol encoded in JSON. It is similar to the XML-RPC protocol, defining only a few data types and commands. JSON-RPC allows for notifications (data sent to the server that does not require a response) and for ...

-based remote control, SQL and

NoSQL A NoSQL (originally referring to "non- SQL" or "non-relational") database provides a mechanism for storage and retrieval of data that is modeled in means other than the tabular relations used in relational databases. Such databases have existed ...

backends,

IMS Ims is a Norwegian surname. Notable people with the surname include: * Gry Tofte Ims (born 1986), Norwegian footballer * Rolf Anker Ims (born 1958), Norwegian ecologist See also * IMS (disambiguation) Ims is a Norwegian surname. Notable people wit ...

VoLTE Voice over LTE (VoLTE) is an LTE high-speed wireless communication standard for mobile phones and data terminals, including Internet of things (IoT) devices and wearables. VoLTE has up to three times more voice and data capacity than older 3G ...

extensions and others.

Kamailio is a Hawaiian word. Kama'ilio means talk, to converse. "It was chosen for its special flavour."

Features

Kamailio is written in pure C with architecture-specific optimizations; it can be configured for many scenarios including small-office use, enterprise PBX replacements and carrier services—it is SIP signaling server—a

proxy Proxy may refer to: * Proxy or agent (law), a substitute authorized to act for another entity or a document which authorizes the agent so to act * Proxy (climate), a measured variable used to infer the value of a variable of interest in climate re ...

—aiming to be used for large real-time communication services. Features include: * SIP telephony system * SIP load balancer * SIP security firewall * Least cost routing engine * IMS/VoLTE platform * Instant messaging and presence services * SIP IPv4-IPv6 gateway * MSRP relay * SIP-WebRTC gateway

Usage

Kamailio is used by large

Internet Service Providers An Internet service provider (ISP) is an organization that provides services for accessing, using, or participating in the Internet. ISPs can be organized in various forms, such as commercial, community-owned, non-profit, or otherwise privatel ...

to provide public telephony service. The largest public announced deployment with several million of users is in operation at the German ISP '' 1&1''. Another large deployment is in operation at the provider

sipgate Sipgate, stylised as sipgate, is a European VoIP and mobile telephony operator. Company Sipgate was founded in 2004 and became one of Germany's largest VoIP service providers for consumers and small businesses. Through its network, which us ...

Forks

OpenSIPS

OpenSIPS, a fork of SER which has diverged—deciding to "go their own way" from the SER and OpenSER codebases—is a

free software Free software or libre software is computer software distributed under terms that allow users to run the software for any purpose as well as to study, change, and distribute it and any adapted versions. Free software is a matter of liberty, ...

implementation of SIP for

voice over IP Voice over Internet Protocol (VoIP), also called IP telephony, is a method and group of technologies for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet. The terms Interne ...

(VoIP) that can be used to handle voice, text and video communication. OpenSIPS is intended for installations serving thousands of calls and is

IETF The Internet Engineering Task Force (IETF) is a standards organization for the Internet and is responsible for the technical standards that make up the Internet protocol suite (TCP/IP). It has no formal membership roster or requirements and ...

RFC 3261 compliant. The software was recognized by Google in 2017 with their Open Source Peer Bonus award.

History

Kamailio's roots go back to 2001, when the first line of SIP Express Router (SER) was written; at the time, the working group published results a
iptel.org
��in September 2002 the code itself was published under the

GPL The GNU General Public License (GNU GPL or simply GPL) is a series of widely used free software licenses that guarantee end users the four freedoms to run, study, share, and modify the software. The license was the first copyleft for general us ...

. The first fork of SER came in 2005—OpenSER—which would later merge back into the code that would become Kamailio. The codebases of SER and OpenSER (by then known as Kamailio) converged in December 2012, and it was decided to continue to use Kamailio as the main name of the project, which remains open source. During the first years of development, ''serweb''—a web-based user provisioning—was available.

Timeline

;2001 :*SIP Express Router (SER) is initially developed by the

Fraunhofer Institute for Open Communication Systems The Fraunhofer Institute for Open Communication Systems, or FOKUS, is an organization of the Fraunhofer Society. Headquartered in Berlin (Charlottenburg), the institute is engaged in applied research and development in the field of Information ...

(FOKUS) ;2002 :*First third-party contribution (

ENUM Telephone number mapping is a system of unifying the international telephone number system of the public switched telephone network with the Internet addressing and identification name spaces. Internationally, telephone numbers are systematicall ...

module) :;September ::*Code is

'd and first published ;2003 :*Adoption by the general public begins; additional free and open source code is contributed by independent third parties ;2004 :*Part of the FOKUS team moves, with the SER copyrights, to the newly created company iptel.org :*Two of the five SER core developers and one main contributor start a new free and

open source Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use the source code, design documents, or content of the product. The open-source model is a decentralized sof ...

software project named OpenSER. ;2005 :*The company IPtel.org is bought by

TEKELEC Tekelec, Inc. was a Morrisville, North Carolina based telecommunications company. It developed hardware and software for networks that are fixed, wireless, or packet-based. It provided IP services to help mobile carriers with network signaling, p ...

, and is responsible for the TEKELEC session router and CSCF. ;2007 :;May 12 ::*SER 2.0 RC-1 (Ottendorf) is made available ;2008 :;August ::*OpenSER is renamed Kamailio to avoid conflict with similar trademarks :;November 4 ::*Kamailio developers sketch and announce a plan to team up with the SER developers to create the future sip-router project ;2013 :*FOKUS and the Kamailio community organize the first iteration of the annual 'Kamailio World' conference in Berlin, Germany.

References

External links

{{Portal, Free and open-source software
Kamailio Homepage
Telephony software Free VoIP software Free server software Free routing software