Compare software

FlexisipKamailio

Best for: Running your own SIP VoIP service, especially for Linphone mobile users

Best for: Telecom engineers building SIP, VoIP or WebRTC platforms

Free

Free under the AGPL 3.0, with a paid proprietary licence for closed-source use.

 Free

Free and open source under the GPLv2 or later.

Self-hosted Linux, Self-hosted
  • Push gateway delivers calls and messages to mobile apps in the background
  • Proxy, presence and B2BUA in one suite
All 4 strengths
  • Push gateway delivers calls and messages to mobile apps in the background
  • Proxy, presence and B2BUA in one suite
  • Powers the public linphone.org SIP service
  • Can run on embedded hardware
  • Handles thousands of call setups per second
  • WebSocket support for WebRTC plus TLS for secure signalling
All 4 strengths
  • Handles thousands of call setups per second
  • WebSocket support for WebRTC plus TLS for secure signalling
  • Wide routing features including load balancing, fail-over and least cost routing
  • Actively maintained with regular stable releases
  • Requires SIP and VoIP knowledge to deploy
  • Conference server is now a separate package
  • Infrastructure for engineers, not an end-user calling app
  • Configuration requires solid SIP and VoIP knowledge
All 3 limitations
  • Infrastructure for engineers, not an end-user calling app
  • Configuration requires solid SIP and VoIP knowledge
  • Handles signalling only; media needs separate servers
Self-hosted Downloadable app, Self-hosted
Open source Open source
License: AGPL-3.0 License: GPL-2.0-or-later
Not stated if an account is needed No account needed
Not stated if it works offline Not stated if it works offline
Sources

Catalog checked October 2, 2026
Sources

Catalog checked October 2, 2026

“Not stated” means we have not confirmed it. Features can vary by device and plan.