Our products and services focus: voice and video over IP applications and communication systems.


Flexisip is a complete, modular and scalable SIP server suite written in C++11, comprising proxy, presence and group chat functions.

Flexisip offers an easy-to-install SIP server solution, offering « out of the box » all the required features to deploy your own SIP service tuned for mobile or desktop applications.

Flexisip can be integrated into your SIP infrastructure for different purposes :


Flexisip instances can be deployed on server machines, in order to run a SIP VoIP service. The free SIP service is running with Flexisip since 2011, and enables Linphone users to create their SIP addresses in order to communicate together.


Thanks to its modular architecture and its limited number of required dependencies, Flexisip can perfectly run on small hardwares (embedded systems).


Push Gateway is a specific operation mode of Flexisip, developed by Belledonne Communications to deliver SIP incoming calls or text messages on mobile device platforms where push notifications are required to receive information while the app is in foreground.

Supporting push notifications was already highly recommended and becomes mandatory on some OS (iOS ≥ 10, Android ≥ 8). The push system is promoted as the efficient, highly reliable, bug-free system to receive information while the phone is off.

Flexisip Push Gateway aims at being integrated into existing SIP infrastructures that do not support push notifications, most of the time without any configuration change.


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

  • under GNU Affero GPLv3 license - for free (open source)
  • under proprietary and commercial license to be used in closed source applications.

Contact for costs and services information.

Read more about Flexisip on