The best free alternative to Asterisk is 3CX. If that doesn't suit you, our users have ranked more than 25 alternatives to Asterisk and 17 is free so hopefully you can find a suitable replacement. Other interesting free alternatives to Asterisk are FreeSWITCH, FreePBX, Wazo and Yate - Yet Another Telephony Engine.
3CX is a software-based, open standards IP PBX that offers complete Unified Communications, out of the box.
Offers a free trial period, after with you need to upgrade to paid subscription.
It's a soft phone, not a VoIP server / exchange
FreeSWITCH is a scalable open source cross-platform telephony platform designed to route and interconnect popular communication protocols using audio, video, text or any other form of media. It was created in 2006 to fill the void left by proprietary commercial solutions.
FreePBX is a web-based open source GUI (graphical user interface) that controls and manages Asterisk (PBX), an open source communication server.
Its a very user friendly Interface which is very easy for beginners to understand
FreePBX operates in tandem with Asterisk, not independent of it.
Wazo is mainly an IPBX that provides communication services such audio, video, and instant messaging based on the use of standard network technologies such as the TCP/IP protocol. It is interoperable with most market telephony systems and gives users access to flexible and...
Yate is a softswitch (concept of separating the network hardware from network software).
Carrier type services - not targeted as a PBX
XiVO is an IP-PBX, a unified communications platform that connects phones on a local or private network with other networks such as public landlines and mobile telephones.
FusionPBX is an open source FreeSWITCH GUI. FusionPBX can be used as a high available single or domain based multi-tenant PBX, carrier grade switch, call center server, fax server, voip server, voicemail server, conference server, voice application server, appliance framework...
Acefone is a UK-based hosted phone system and cloud communication provider that can help you to streamline your business communication & customer service operations.
Kamailio® (successor of former OpenSER and SER) is an open source SIP server released under GPL, able to handle thousands of call setups per second. Among features: asynchronous TCP, UDP and SCTP, secure communication via TLS for VoIP (voice, video); WebSocket support for...
Vodia Phone app is a free add-on for your Vodia PBX that lets you connect to your account on your Vodia PBX. Starting with Android 5.0 Lollipop, based on the WebRTC technology.
A robust SIP/H.323/WebRTC softswitch for Windows with a long list of features including PBX and billing.
Cyprus
EU
France
Romania
Easy to use, easy to install, feature rich