Voice Over Internet Protocol (VoIP) – a set of technologies that enable the delivery of voice communications over the Internet. There are four major components to a VoIP network.
- Call Processing Server/IP PBX – establish, monitor and terminate communications
- User End-Devices – VoIP phones or softphones that are used by end-users to initiate the communications
- Media/VoIP Gateways – interface the voice content uses so it can be transported over the IP network
- IP network – the IP backbone provides the connectivity among the distributed elements
VoIP signaling protocols are the enablers of the VoIP network. The protocols determine what types of features and functionalities are available, as well as how all of the VoIP components interact with one another. Examples include H.323, real-time transport protocol (RTP) and session initiation protocol (SIP).