Liblinphone is a high level library integrating all the SIP video calls feature into a single easy to use API. Usually telecommunications is made of two things: media (transport of voice or video, encoding and decoding...), and signaling (routing calls, ringing, accepting a call etc...).

Liblinphone aims at combining the two things together and doing most things automatically. This makes it easier to the programmer to implement video calls in any application, without being an expert in VoIP and telecommunications. Liblinphone is an open source library based on Mediastreamer2 for voice/video streaming, and belle-sip for SIP signaling.

Liblinphone in Linphone architecture

Linphone and linphonec are directly based on Liblinphone.


Signaling features

  • SIP user agent compliant with RFC 3261
  • IPv6 dual stack mode
  • Digest authentication
  • Supports multiple calls simultaneously with call management features: hold on with music, resume, transfer...
  • Multiple SIP proxy support: registrar, proxies, outbound proxies
  • Text instant messaging with delivery notification
  • Presence using the SIMPLE standard in peer to peer mode
  • DTMF (telephone tones) support using SIP INFO or RFC 2833

Media features

Liblinphone leverages on mediastreamer2 engine for rendering audio & video streams, and as such takes advantages of all features implemented in mediastreamer2.


Liblinphone is available on the following platforms:

  • Linux Debian 6/7, Centos 6/7 (x86, x86_64, ARM v5 to v7, blackfin)
  • Windows XP, Vista, 7 and 8 (x86, works also on x86_64)
  • Apple Mac OS X 10.7 to 10.10 (x86_64)
  • Apple iOS 6 to 8 (ARM v7, ARM 64)
  • Google Android 4 to 6 (ARM v5 to v7, x86)
  • BlackBerry OS10 (ARM v7)
  • Windows Phone 8 and 8.1 (ARM v7)

Implemented standards

Registration, calls

  • Session Initiation Protocol, RFC 3261
    • 8. General User Agent behaviour
    • 9. Cancelling a request
    • 10. Registrations
    • 12. Dialogs
    • 13. Initiating a session
    • 14. Modifying an existing session
    • 15. Terminating a session
    • 17. Transactions
    • 18. Transports
    • 22.4 The Digest Authentication Scheme
  • Session Description Protocol, RFC 4566
  • An Offer/Answer Model with the Session Description Protocol (SDP), RFC 3264
  • An Extension to the Session Initiation Protocol (SIP), RFC 3581 (use of rport parameter)
  • Session Initiation Protocol (SIP) INFO Method and Package Framework, RFC 6086
    • 4. The INFO Method
  • The Session Initiation Protocol (SIP) Refer Method, RFC 3515
    • 2. The REFER Method
  • Session Description Protocol (SDP) Security Descriptions for Media Streams, RFC 4568
  • Managing Client-Initiated Connections in the Session Initiation Protocol (+sip.instance parameter), RFC5626
  • Connection reuse in the Session Initiation Protocol (alias parameter), RFC5923
  • Correct Transaction Handling for 2xx Response to Session Initiation Protocol (SIP) INVITE Requests, RFC6026
  • A privacy mechanism for the Session Initiation Protocol, RFC3323
  • Private Extensions to the Session Initiation Protocol (SIP) for Asserted Identity within Trusted Networks, RFC3325
  • Indication of message composition in instant messaging, RFC3994

Presence and Instant Messaging

  • Session Initiation Protocol (SIP)-Specific Event Notification, RFC 3265
  • A Presence Event Package for the Session Initiation Protocol (SIP), RFC 3856
  • Session Initiation Protocol (SIP) Extension for Instant Messaging, RFC 3428 (only text/plain messages)
  • Session Initiation Protocol (SIP) Extension for Event State Publication, RFC 3903 (Creation of PUBLISH requests)
  • A Data Model for Presence, RFC 4479
  • RPID: Rich Presence Extensions to the Presence Information Data Format (PIDF), RFC 4480





Liblinphone is dual licensed. It can be licensed and distributed:

  • under GNU GPLv2 license - for free (open source)
  • under proprietary and commercial license to be used in closed source applications. Contact Belledonne Communications for costs and other service information.


Liblinphone Android version:

Liblinphone iOS version:

Liblinphone Blackberry:

Liblinphone win32 SDK version:


Liblinphone macos SDK version:

Source code

Project git

linphone, including:

  • oRTP
  • mediastreamer2
  • liblinphone
  • linphonec
  • linphone (gtk)

git clone git:// --recursive

Liblinphone BB10



The Liblinphone wiki gives good hints to start programming with liblinphone.

The API reference documentations are available in various formats depending on the target programming language:

Liblinphone C API documentation (used for Linux, Windows, Mac and iOS) documented with Doxygen.

Liblinphone's Java wrapper for Android applications.

Python wrapper documentation 

JavaScript API documentation for programming with the linphone-web plugin.