List of Top Free Open Source & Self Hosted Application for Communication - SIP

SIP/IPBX telephony software.

Asterisk – Easy to use but advanced IP PBX system, VoIP gateway and conference server. GPL-2.0 C
ASTPP – VoIP Billing Solution for Freeswitch. It supports prepaid and postpaid billing with call rating and credit control. It also provides many other features. AGPL-3.0 PHP
Eqivo – Eqivo implements an API layer on top of FreeSWITCH facilitating integration between web applications and voice/video-enabled endpoints such as traditional phone lines (PSTN), VoIP phones, webRTC clients etc. MIT PHP
Flexisip – A complete, modular and scalable SIP server, includes a push gateway, to deliver SIP incoming calls or text messages on mobile device platforms where push notifications are required to receive information when the app is not active in the foreground. AGPL-3.0 C/Docker
Freepbx – Web-based open source GUI that controls and manages Asterisk. GPL-2.0 PHP
FreeSWITCH – Scalable open source cross-platform telephony platform. MPL-2.0 C
FusionPBX – Open source project that provides a customizable and flexible web interface to the very powerful and highly scalable multi-platform voice switch called FreeSWITCH. MPL-1.1 PHP
Kamailio – Modular SIP server (registrar/proxy/router/etc). GPL-2.0 C
Kazoo – KAZOO is an open-source, highly scalable software platform designed to provide carrier-grade VoIP switch functions and features. MPL-1.1 Erlang
openSIPS – OpenSIPS is an Open Source SIP proxy/server for voice, video, IM, presence and any other SIP extensions. GPL-2.0 C
Routr – A lightweight sip proxy, location server, and registrar for a reliable and scalable SIP infrastructure. MIT Docker
SIP3 – VoIP troubleshooting and monitoring platform. Apache-2.0 Kotlin
SIPCAPTURE Homer – Troubleshooting and monitoring VoIP calls. AGPL-3.0 Angular/C
Wazo – Full-featured IPBX solution built atop Asterisk with integrated Web administration interface and REST-ful API. GPL-3.0 Python
Yeti-Switch – Transit class4 softswitch(SBC) with integrated billing and routing engine and REST API. GPL-2.0 C++/Ruby