2. The Basics Voice Over Internet Protocol (VoIP) is an internet based voice communication system. Basic Steps of a VoIP system: Conversion of analog voice signals to digital format Compression/translation of the signal into IP packets Transmission via the Internet Private Branch Exchange (PBX) is a high-quality telephone system that makes connections among the internal telephones of a private organization — usually a business — and also connects them to the public switched telephone network (PSTN) via trunk lines.