What is OpenSIPS? As you are reading this blog post, you must already know what OpenSIPs is, but still, it is good to take a look at this powerful VoIP development technology before we jump into an installation guide. OpenSIPs is an acronym for Open Session Initiation Protocol Server. It is very popular among open source VoIP community members and top VoIP development companies as a multipurpose and multifunctional SIP server. It can also operate as a signaling server and it can be used in multiple applications with custom OpenSIPs development such as: SIP Registrar SIP Router/Switch SIP Switch SIP