Best Communication - SIP software in 2026

Asterisk

asterisk.org

Open source

Easy to use but advanced IP PBX system, VoIP gateway and conference server.

Flexisip

linphone.org

Open source

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.

Freepbx

freepbx.org

Open source

Web-based open source GUI that controls and manages Asterisk.

FreeSWITCH

freeswitch.org

Open source

Scalable open source cross-platform telephony platform.

FusionPBX

fusionpbx.com

Open source

Web interface for multi-platform voice switch called FreeSWITCH.

Kamailio

kamailio.org

Open source

Modular SIP server (registrar/proxy/router/etc).

openSIPS

opensips.org

Open source

SIP proxy/server for voice, video, IM, presence and any other SIP extensions.

Routr

routr.io

Open source

Lightweight SIP proxy, location server, and registrar for a reliable and scalable SIP infrastructure.

SIP3

sip3.io

Open source

VoIP troubleshooting and monitoring platform.

SIPCAPTURE Homer

sipcapture.org

Open source

Troubleshooting and monitoring VoIP calls.

Wazo

wazo-platform.org

Open source

Full-featured IPBX solution built atop Asterisk with integrated Web administration interface and REST-ful API.

Yeti-Switch

yeti-switch.org

Open source

Transit class4 softswitch(SBC) with integrated billing and routing engine and REST API.