Apps similar to Kamailio include Asterisk, which is free and open source. Other options are 3CX, FreeSWITCH, FreePBX and Yate - Yet Another Telephony Engine. You can choose from more than 10 IP PBX Systems like Kamailio for Linux, Windows, Mac, self-hosting and Android.
The MiRTA PBX is an interface written in PHP using Mysql as backend to manage a multitenant PBX built over the Asterisk Open Source PBX. An easy to use interface allows you to manage one or more Asterisk PBX in a multi tenant, load sharing and high availability configuration.
OpenSIPS (Open SIP Server) is a mature Open Source implementation of a SIP server. OpenSIPS is more than a SIP proxy/router as it includes application-level functionalities. OpenSIPS, as a SIP server, is the core component of any SIP-based VoIP solution.
Ozeki Phone System XE is a Software PBX telephony platform for Windows. Ozeki enables your applications to connect PBX and access IVR, Webphone, SMS sending, 3D video calls and other functionalities. It makes possible to use PHP VOIP, .
Japan
A robust SIP/H.323/WebRTC softswitch for Windows with a long list of features including PBX and billing.
Romania
EU
IvozProvider supports multiple management levels, from Global platform administrator to final user, each of them having its own web interface with visibility to perform configuration tasks.
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.
