https://www.kamailio.org/w/
The Kamailio SIP Server Project – The Open Source SIP Server
sip serveropen sourceproject
https://www.3cx.com/phone-system/sip-server/
3CX SIP Server Software. Open-standards. Hosted or On-premise
Dec 24, 2025 - 3CX SIP server software is a communications solution that works with popular IP phones, gateways and SIP trunk providers. Install in minutes.
sip serveropen standardson premise3cxsoftware
https://routr.io/
A SIP server by Fonoster
sip server
https://www.ejabberd.im/
ejabberd XMPP Server with MQTT Broker & SIP Service
ejabberd is an XMPP server (Jabber server), MQTT broker and SIP gateway built to create awesome realtime services like massive chat, instant communication, IoT...
xmpp serverejabberdmqttbrokersip
https://www.f5.com/glossary/sip-proxy-server
What is a SIP Proxy Server? | F5
Learn more about the SIP proxy server, which controls calls and IP addresses in a SIP-enabled network.
what isproxy serversipf5