PhoneWhat it triggersThe softwareFaxWhat a fax costsVerified fax lines

The software

Surveyed against the GitHub API. Star counts are a staleness marker, not a quality judgement — last push is the field that matters, and the licence column is the one that decides whether you can host it.

App-to-app — build these first

ProjectRoleLicenceLast push
livekit/livekitWebRTC SFU + SDKs Apache-2.02026-09-07
versatica/mediasoupWebRTC SFU library ISC2026-09-07
meetecho/janus-gatewayWebRTC gateway GPL-3.02026-09-07
pion/webrtcWebRTC in pure Go MIT2026-09-07
coturn/coturnSTUN/TURN relay see repo2026-09-07
onsip/SIP.jsBrowser SIP client MIT2026-06-15
AzuraCast/AzuraCastFull radio station platform AGPL-3.02026-09-07
libretime/libretimeRadio automation AGPL-3.02026-09-07
savonet/liquidsoapStream scripting engine GPL-2.02026-09-07
xiph/Icecast-ServerStream server GPL-2.02026-08-19
owncast/owncastSelf-hosted live video + chat MIT2026-09-07
bluenviron/mediamtxRTSP/RTMP/WebRTC/HLS relay MIT2026-09-07
ossrs/srsStreaming cluster MIT2026-09-05
jitsi/jitsi-meetVideo conferencing Apache-2.02026-09-07
element-hq/synapseMatrix homeserver — messaging + VoIP signalling AGPL-3.02026-09-07

Only once there are real numbers

ProjectRoleLicenceLast push
asterisk/asteriskPBX / SIP see repo2026-09-02
signalwire/freeswitchSoftswitch see repo2026-09-04
kamailio/kamailioSIP proxy / registrar see repo2026-09-07
fonoster/routrSIP server, modern stack MIT2026-09-07

⚠️ Licences that constrain a hosted service

The AGPL network clause triggers on offering software over a network, even though nothing is distributed. That is fine if we publish the source, and it is a decision if we do not.

azuracast — AGPL-3.0

AGPL network clause: offering this over a network to users triggers the source obligation even though nothing is distributed. Fine if we publish; a decision if we do not.

libretime — AGPL-3.0

AGPL network clause: offering this over a network to users triggers the source obligation even though nothing is distributed. Fine if we publish; a decision if we do not.

synapse — AGPL-3.0

AGPL network clause: offering this over a network to users triggers the source obligation even though nothing is distributed. Fine if we publish; a decision if we do not.

Engineering and regulatory orientation, not legal advice. The FCC obligations named here are real and enforced; confirm your own position with counsel before carrying a single call to a phone number.