VOIP stands for Voice over Internet Protocol (VoIP) and PBX stands for private box exchange. It is a business telephone system that offers services like a usual PBX and uses LAN or WAN network.
VoIP PBX systems can shift calls between either VoIP or local lines or between VoIP and conventional telephone users, like a PBX would. A VoIP PBX system can be hardware based or a software system.
VOIP gateways can be aligned with typical PBX functionality to monitor their managed intranet and help in reducing long distance bills, better mobility, and improved redundancy.
VOIP PBX works in two different ways. It can either work as a hardware object, or, if taking into consideration its virtual role, it can work as a complete software system.
SIP stands for Session Initiation Protocol.
Some PBXs can be enabled for using multimedia communication (initiating and receiving voice and video calls over an IP network). The entire system uses improved encryption technology and proxy servers to generate call sessions over an existing internet network.
Virtual PBX services have the ability to host voice, video and data conferencing. A business can therefore work through distance without having to invest in any a additional software or hardware. Furthermore, virtual PBX systems offer online ways to trace call data, which can help with billing and planning.