New release of Flexisip, our SIP-based server suite

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Since its 1.0 release announced in 2015, Flexisip has regularly evolved in a "rolling release" model, suiting well to our goal of enriching rapidly its feature set, at the cost of sometimes breaking configuration compatibility.

With this 2.0 release comes the time for maturity. The feature set is now more than sufficient to power a complete real-time communication network, with secure authentication, audio, video, chat and ICE. This release focuses on providing a stable, clean, and robust reference to deploy communication networks on the long term.


The last feature that entered the 2.0 release is the support of RFC8599 for the transmission of the push notification information through REGISTER requests, where we leverage to adapt to iOS 13 new push notification constraints.

Some other important features were added during the last years, for example:

  • ExternalAuthentication, a new proxy module that performs SIP request authentication based on the inputs of an external http service. It typically allows Flexisip to interact with a third party authentication service in order to authenticate a SIP request.
  • The “Server known resource lists” feature, a feature that allows to directly provision a Liblinphone-based client with a server defined contact list, together with associated presence information. The typical use case can be to have team workers sharing a common company-defined address book on their communication app.

Please refer to our changelog file for a detailed description of flexisip 2.0 release.


The Flexisip software now comprises three modules: proxy, presence and conference (the latter being required for Linphone's group chat features).

This server suite is typically suitable to deploy your own cloud SIP service tuned for your Linphone-based application, especially since it supports push notifications (including iOS13 new requirements).


Flexisip services can be installed at your premises or on a machine rented from a cloud service provider, such as AWS, Azure or OVH.

Documentation, configuration, and management tools have been entirely reviewed and improved to ease the work of system administrators in charge of configuration or maintenance.
-> Source code can be downloaded from our Gitlab or cloned with Git.
-> The Flexisip documentation is available on our public Wiki.

As a company, we also sell installation, configuration and support services for the Flexisip software, as well as proprietary licenses to customers who do not want to use it via its open source license (Affero GPLv3).
Do not hesitate to contact us to discuss your complete client and server VoIP project!

Leveraging on this strong milestone, the development of Flexisip will of course continue, with new features, performance, interoperability and scalability improvements to come in the next months.