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Asterisk vs Flexisip: catalog facts
Asterisk	Flexisip
Free Free and open source.	Free Free under the AGPL 3.0, with a paid proprietary licence for closed-source use.
Linux, Self-hosted	Self-hosted
Run your own PBX and VoIP system Flexible enough to build custom telephony setups	Push gateway delivers calls and messages to mobile apps in the background Proxy, presence and B2BUA in one suite
Configuration requires telephony knowledge A framework to build on rather than a ready-to-use phone system	Requires SIP and VoIP knowledge to deploy Conference server is now a separate package
Downloadable app, Self-hosted	Self-hosted
Open source	Open source
License not stated	License: AGPL-3.0
No account needed	Not stated if an account is needed
Not stated if it works offline	Not stated if it works offline
Official website Full listing and sources Checked September 24, 2026	Official website Full listing and sources Checked October 2, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.